90A ANNUAL MEETING ABSTRACTS for endometrial carcinoma, the sensitivity and specificity of detecting endometrial Results: As a marker of tumor aggressiveness, upregulation of Bcl2 in the tumor cells malignancy were 72.7% and 100%, respectively. The positive predictive value is was marginally significant (p=0.047), upregulation of hMSH2 was significant in both 100%. tumor cells and the non tumor internal control cells (p=0.026 and 0.003 respectively); expression of αSMA was restricted to the stroma in aggressive tumors (p<0.001) and to the tumor cells in the non aggressive tumors (p=0.029). Stromal expression of αSMA was highy predictive of aggressive behavior (p,0.001; accuracy 87%). Logistic regression combining the expression of αSMA and hMSH2 yielded a predictive model with 97% accuracy (p<0.001). Neither the expression of β -catenin nor that of Cyclin D1 was statistically significant for predicting aggressiveness of BCC. Conclusions: Aggressive BCC express αSMA in the stroma while non aggressive BCC express αSMA in the tumor cells. Stromal expression of αSMA is an accurate, reliable, and easy to use marker of aggressiveness in BCC and can be used in clinical practice for surgical therapeutic decisions.

403 D2-40 a Novel Immunohistochemical Stain as a Complementory or Possible Replacement to Factor XIIIa and CD34 Immunoperoxidase Stains in Differentiating Dermatofibroma and Dermatofibrosarcoma Protuberance B Bandarchi, S Hafezi, F Siadat, G Rasty. University of Toronto, Toronto, ON, Canada. Background: Usually differentiating between dermatofibroma (DF), particularly cellular variant and dermatofibrosarcoma protuberance (DFSP) in excisional Conclusions: In this prospective study, we demonstrate that Thin Prep Pap test has are straightforward. However, differentiating between these two entities may become a reasonably high sensitivity and/or specificity in detecting endometrial carcinoma. problematic in superficial biopsies. Both DF and DFSP are composed of dermal spindle Based on our findings, the ThinPrep Pap test may be used as a primary screening test cell proliferation, which may also demonstrate storiform pattern. Although changes of for endometrial carcinoma for high risk population. overlying epidermis as well as grenz zone are soft signs of dermatofibroma, in a minority of cases the distinction is problematic. Majority of dermatofibromas and DFSPs are 401 Urothelial Cell Clusters in Voided Urine Cytology Specimens: A positive for factor XIIIa and CD34 immunostains, respectively. However, reportedly Histologic and Cytologic Review of 146 Patients there are some cases revealing overlapping staining and conflicting results. In this study MD Zieske, MB Cohen, CS Jensen. University of Iowa, Iowa City, IA. we compared the results of different immunoperoxidase stains. Background: The evaluation and classification of atypical urine cytology specimens Design: 20 cases of DF (including 6 cellular variant) and 24 cases of DFSP were selected remains challenging and controversial. The presence of urothelial cell clusters in voided from archives of Department of Anatomic at Sunnybrook Health Sciences urine specimens has historically been considered an atypical finding, suggesting an Centre, University of Toronto. We applied Factor XIIIa, CD34 and monoclonal mouse increased risk of urothelial neoplasia. However, recent literature has not only questioned anti D2-40 immunoperoxidase stains to formalin-fixed, paraffin-embedded tissue the value of reporting urothelial cell clusters, but suggested it is misleading. The aim of sections. D2-40 immunoperoxidase stain identifies a 40 kD O-link sialoglycoprotein our study was to determine the significance of urothelial cell clusters in voided urine present on a variety of tissues including testicular germ cell tumors as well as lymphatic cytology specimens at our institution. endothelium. Design: The final reports of 3135 consecutive voided urine specimens over a 7 year Results: All 20 (100%) cases of DF revealed strong and diffuse D2-40 staining of spindle period (2000-2006) were searched for cases interpreted as atypical based only on the cells as well as stroma. Factor XIIIa showed strong and diffuse positivity in spindle presence of urothelial cell clusters without other significant cytologic atypia. Correlation cells, more prominent at the periphery of lesions. All spindle cells were negative for with the results of subsequent histologic (within 60 days) and cytologic specimens CD34 immunostain except one case revealing focal CD34 positivity. Interestingly this was performed. focus was negative for D2-40 (mirror image). All DFSPs revealed strong and diffuse Results: 167 specimens (5.33% of all voided urine specimens) from 146 patients positivity for CD34 and negativity for factor XIIIa. 4/24 (16%) cases of DFSPs showed (male, 99; female, 47; mean age, 58.9 years) were identified with 15 patients having positivity by D2-40, however the staining pattern was faint, patchy and non-crisp, in multiple specimens. Histologic and cytologic follow-up was available in 26 (17.8% of contrary to diffuse, strong, granular and sharp staining in DF. 146 patients) and 59 (40.4%) patients, respectively. 61 (41.8%) patients had no further Conclusions: D2-40 appears to be a novel immunohistochemical stain, which is 100% specimens at our institution. In patients with histologic follow-up, 14 patients (9.6%) positive in dermatofibromas, including cellular variant. It may show focal and faint had low-grade urothelial carcinoma (UC), 2 (1.4%) had high grade UC, and 1 (0.7%) stromal staining in DFSP. We suggest D2-40 utilization is complementary or even had urothelial . In patients with cytologic follow-up, 1 (0.7%) patient had high replacement to factor XIIIa and CD34 immunostaining in superficial biopsies in which grade UC, 6 (4.1%) had atypical findings, and 11 (7.5%) had urothelial cell clusters the junction of dermis and subcutaneous tissue is not present for definitive diagnosis. in subsequent voided specimens. Additionally, two patients underwent subsequent nephrectomy for renal (papillary renal carcinoma and cystic nephroma). The 404 Characterization of Epidermal Merkel Cell Density Adjacent to remaining patients with follow-up (49, 33.6%) had benign/reactive findings. In total, Merkel Cell Carcinomas 17 patients (11.6%) had a subsequent diagnosis of urothelial carcinoma. Of those 17 EA Bantle, JS Lewis, J Lennerz. Washington University in St. Louis, St. Louis, MO. patients, 9 (52.9%) had no prior history of urologic malignancy at our institution. Background: Merkel cell carcinoma (MCC) is a unique and highly aggressive Conclusions: The presence of urothelial cell clusters in voided urine specimens neuroendocrine carcinoma of the skin. It has an incidence of 0.23 per 100,000 people correlates with a measureable risk of underlying urothelial neoplasia. Their presence in the United States. Although relatively rare, the grave prognosis makes it an area of in voided urine specimens should continue to be reported to clinicians to facilitate particular clinical concern. The pathobiology of MCC is poorly understood. It is well appropriate clinical follow-up. known that MCC is typically an intradermal tumor, but there very rare reports of MCC in-situ. Whether or not there is a pre-neoplastic state that acts as the precursor lesion to the invasive tumor is not known. The aim of this study was to discern whether or not Dermatopathology there is Merkel cell within the epidermis overlying the invasive tumor. Design: A total of 21 resection specimens for MCC with overlying epidermis were identified in the files of Washington University from 1989 to the present. The cases, along 402 Immonuhistologic Determinants of Aggressiveness in Basal Cell with 21 site-matched controls, were immunostained for chromogranin-A (chr-A) and Carcinoma cytokeratin 20 (CK20) on 4-micron thick sections using standard autostainer protocols. PA Adegboyega, S Rodriguez, J McLarty. Louisiana State University Health Sciences Sections were examined by one study pathologist (EB), and the number of Merkel cells Center, Shreveport, LA; University of Texas Medical Branch, Galveston, TX. quantified in the epidermis and hair follicles overlying the tumor. A total of 5 linear mm Background: Basal cell carcinoma (BCC) is a very common malignant skin tumor of epidermis directly above the tumors as well as the entire epidermis on control sections that rarely metastasizes but is often locally aggressive. Search for clinically useful (2-49 mm) was examined and counted for positive cells in each case. markers of aggressiveness is still on-going. Bcl2, β-Catenin, Cyclin D1, hMSH2 and Results: MCC cases had an average of .49/.50 Merkel cells per mm (for chr-A and CK αSMA are previously reported but inconlusively, to have potential for predicting BCC 20, respectively), whereas normal cases showed .66/.95. The density of Merkel cells aggressiveness. We therefore studied their expression as prognostic indices, in a group within the epidermis adjacent to MCC was significantly less (p < 0.5) than that of normal of clinically proven aggressive BCC from the head and neck region. controls (Wilcoxon signed rank test). The number of Merkel cells counted on sections Design: The study materials consisted of 28 cases of aggressive BCC based on >2 stained with chr-A and ck 20 was correlated, (r = 0.5561; CI 0.17-.79) indicating that recurrences, tumor size >3 cm, and infiltration of deeper structures. 35 randomly they are both good markers for Merkel cells. In addition, two types of morphologically selected cases of BCC were also studied as controls. Representative tissue sections were distinct Merkel cells, those with dendritic processes and those without, were identified immunostained and the expression of the gene products of interest was evaluated using a in all specimens. The dendritic-type appeared to be more concentrated around the hair semiquatitative scale of 0-4. Also, their topographic locations were noted. The expression follicles while the non-dendritic type tended to be found in the stratum basale. of each gene product was compared between the tumor cells and the corresponding non Conclusions: The density of Merkel cells in the epidermis overlying MCC is not tumor cells in the same tissue section. The results of the two study groups were subjected increased when compared to site matched controls. Unlike and certain to statistical analysis and the gene products with statistically significant dysregulation carcinomas, an intraepidermal proliferation of neoplastic cells does not appear to precede were analyzed further (by logistic regression) to generate reliable immunohistologic the development of MCC in most cases. criteria for determining the aggressiveness of BCC. The accuracy of the criteria was tested using the Omnibus tests of model coefficients. ANNUAL MEETING ABSTRACTS 91A

405 Risks Associated with Permanent Synthetic Dermal Fillers particularly since the latter tumor may lack CD45 and/or CD20, yet both neoplasms CJ Bechert, B Ackerman. National Cancer Institute, Bethesda, MD; Ackerman Academy may express PAX-5, a B-cell associated marker. of Dermatopathology, New York, NY. Background: Modern permanent synthetic dermal fillers consist of particulates 408 Immunohistochemical Expression of Bif-1 and Bax in Primary suspended in a resorbable carrier solution. Some common brands are ArteColl/ArteFill, Cutaneous Merkel Cell Carcinoma Dermalive/Dermadeep, Aquamid, Bioplastique, Evolution, and Matridex. In 2006, the KB Calder, SM Schlauder, L Turner, MB Morgan. University of South Florida, Tampa, FDA approved the first non-resorbable, aesthetic injectable dermal implant (ArteFill, FL. made by Artes Medical USA, Inc.) for use in nasolabial folds. Although FDA approval Background: Bax-interacting factor-1 (Bif-1) binds to Bax which in turn activates this of ArteFill was based on data from a 12-month clinical trial conducted by the company, proapoptotic protein. In the absence of Bif-1, the ability to induce through no long-term studies have proven the safety of it or of similar products. This is of the intrinsic pathway is greatly reduced. Merkel Cell Carcinoma (MCC) classically particular concern because permanent synthetic dermal fillers are essentially foreign demonstrates an aggressive behavior and lack of response to chemotherapy, which bodies injected into the skin, thereby acting as a potential source of stimulation and remains unexplained. Previous studies have documented the presence of Bax in MCC, of long-term side-effects. but Bif-1 expression has not been evaluated. Herein, the expression of Bif-1 and Bax Design: We report clinical features and histopathological findings in two patients who in cutaneous MCC is examined. had adverse reactions after having been injected cutaneously with the fillerArteColl and Design: The immunohistochemical expression of Bif-1(provided by Dr Wong at Moffitt the new dermal Matridex. Additionally, we reviewed the literature for the past 10 years Cancer Center and Research Institute Tampa, Fl) and Bax (pre-diluted, GeneTec, Texas) of reported cases of complications associated with modern permanent dermal fillers. protein were examined in 9 cases of MCC. Both positive and negative controls were Results: Adverse effects of permanent synthetic dermal implants are unpredictable, conducted. All the cases were reviewed by a single dermatopathologist. sometimes occurring months or years after the procedure, and at times leading to Results: Bif-1 was detected in 9 cases (100%) and Bax was expressed in 6 cases (66%) disfiguring erythematous nodules that histopathologically show a foreign body of MCC. The percent positive cells for Bif-1 in MCC ranged from 85-98% positive granulomatous reaction. Even though such reactions are rare, when they occur, the (mean 93.9%). At the same time, decreased Bax expression was demonstrated with consequences may be devastating. 0-8% positive cells (mean 3.45%). Conclusions: As a permanent foreign body injected into the skin, synthetic dermal Conclusions: The increased expression of Bif-1 in MCC is associated with low levels fillers are inherently prone to cause adverse reactions, some of them immediate and of Bax staining. These findings suggest that the up-regulation of Bif-1 could in part others delayed, even years after the injections. Given the numerous reports of adverse be responsible for tumorigenesis in cutaneous MCC. As demonstrated, Bax and Bif-1 reactions occurring years later, permanent synthetic dermal fillers should be reserved expression are not exclusively antithetical; therefore, future studies evaluating the for reconstructive procedures and not for cosmetic ones. expression of both proteins should be conducted.

406 Acetylcholine Expression in Merkel Cell Carcinoma 409 Interobserver Variability in Differentiation of Nodal Nevus from JW Bowers, SM Schlauder, KB Calder, JJ Aufman, MB Morgan. University of South Micrometastasis in Sentinel Lymph Adenectomy Specimens Florida College of , Tampa, FL. N Cetin, M Bannan, F Darvishian, C Hajdu, D Nonaka, W Ye, Z Pei, J Melamed. NYU, Background: Neurocrest-derived tissues express muscarinic and nicotinic acetylcholine New York; Karolinska Inst, Stockholm, Sweden. receptors (mAChR and nAChR respectfully). These receptors are critical for migration Background: Sentinel lymph node status is a strong predictor of prognosis in cutaneous of neurocrest-derived cells to their corresponding tissues during development. Recent malignant melanoma. Benign nodal nevus (NN) in sentinel lymph nodes can mimic reports demonstrate neurocrest derived melanoma and numerous non-Merkel cell melanoma micrometastasis (MM) and may be difficult to differentiate in select cases. neuroendocrine tumors express both muscarinic and nicotinic receptors. In light of Therefore, we reviewed and studied the interobserver variability in evaluation of MM the controversy surrounding the origin and of Merkel cell carcinoma versus NN in sentinel lymph nodes biopsied in melanoma. (MCC), we investigated the immunohistochemical expression of both mAChR and Design: Sentinel lymphadenectomy cases, where small melanocytic lesions, either nAChR in MCC. capsular nevus or melanoma micrometastasis were identified and all slides retrieved Design: Fifteen cases of primary non-metastatic cutaneous MCC archived at a large for study. Cases with macrometastases were excluded from the study. Five routine VA hospital and tertiary referral dermatopathology service were retrieved by computer Hematoxylin-Eosin (HE) slides and immunohistochemical stains (Melan-A, HMB- assisted search. We used the following for : conjugated 45, and S-100) were independently evaluated by five experienced pathologists. rabbit anti-human muscarinic M3 acetylcholine receptor Antibody (ABR-Affinity Interobserver variability in diagnoses of nodal melanocytic lesion was studied by using BioReagents Golden, CO); conjugated rabbit anti-muscarinic acetylcholine receptor kappa statistical analysis. M5 monoclonal antibody (Novus Biologicals Littleton, CO); and conjugated rat anti- Results: Overall, all pathologists showed substantial agreement in the diagnosis of nodal nicotinic acetylcholine receptor (beta 2 subunit) monoclonal antibody (Sigma-Aldrich nevus or metastasis (34 of 41 cases concordant; kappa value 0.79; 95% CI, 0.69–0.89). St. Louis, MO). All the cases were confirmed prior to study by a single board certified In 7 of 41 cases (17 %) there were differing diagnoses as follows: 1 of 5 pathologists dermatopathologist. diagnosed NN, and 2 of 5 diagnosed NN in 3 and 4 of the cases respectively. The Results: Fifteen cases of primary cutaneous MCC were diffusely positive for M3 and concordant cases of NN showed classic features – location in the capsule or fibrous M5 mAChR staining. All cases lacked immunohistochemical staining for the beta 2 trabeculae, cytologically bland appearance with frequent spindled morphology, nAChR. negative or only focal and weak reactivity for HMB-45. MM concordant cases showed Conclusions: Despite the limited number of cases, MCC appears to uniformly express intraprenchymal location and larger size (>30 cells). Common features in discordant M3 and M5 receptors. These receptors have been linked to cell proliferation and cases were small size of the lesion (clusters <10 cells, not persisting on all levels), migration which might confer a potential therapeutic target. Further studies directed at intraparenchymal location or epithelioid morphology of nevoid cells. confirming this relationship and a possible autocrine mechanism are needed. Conclusions: This study demonstrates that the differentiation of nodal nevus from micrometastasis by evaluating of the HE slides along with immunohistochemical 407 Reactivity with TdT in Merkel Cell Carcinoma stains for Melan-A, HMB-45, and S-100 can be difficult without full concordance by CJ Buresh, BR Oliai, RT Miller. ProPath Laboratory, Dallas, TX. experienced pathologists. In such cases more cautious approach by surgical pathologists Background: Merkel cell carcinoma (MCC) is a high-grade neuroendocrine carcinoma should be used including the comparison of primary lesion, and ancillary studies. In of skin characterized by cells with a “blastic” appearance; scant cytoplasm, and fine, such cases, the term nodal melanocytic lesion of undetermined significance may be evenly distributed chromatin. Terminal deoxynucleotidyl transferase (TdT) is a DNA utilized to indicate uncertainty and allow for appropriate surveillance and cautious polymerase present in thymic T-cells, lymphoblastic lymphoma/leukemia, and some management by oncologists. cases of acute myeloid leukemia. MCC and lymphoblastic lymphoma/leukemia may have a similar morphologic appearance, and TdT reactivity in MCC has not been 410 Prospective Evaluation of an Extended Histologic Protocol for described. After observing TdT reactivity in a case of MCC, we evaluated a series of Detection of Melanoma Micrometastasis MCC to determine the spectrum of reactivity with this marker in these tumors. N Cetin, M Bannan, B Wang, J Melamed. New York University Medical Center, New Design: We reviewed 24 cases of MCC, the diagnoses confirmed by immunoreactivity York, NY. with cytokeratin 20 and neuroendocrine markers in each case, and performed an Background: Sentinel lymph node status is a strong predictor of prognosis in cutaneous immunohistochemical stain for TdT on each tumor. Positive control material consisted malignant melanoma. Current recommendations for histopathological evaluation of of multi-tumor block sections mounted on the same slides as the patient tissue. The sentinel lymph node in melanoma are limited to 6 levels (3 Hematoxylin-Eosin (HE) number of immunoreactive tumor cells was scored using a four-tiered scale: reactivity levels with alternating S-100 and HMB-45, levels: 1,3,5). More recently an increased in less than 1% of cells was scored as 0, reactivity in 1-25% of cells was scored as 1+, sensitivity of detecting metastasis has been suggested through use of a modified extended reactivity in 26-50% of cells was scored as 2+, and reactivity in greater than 50% of pathologic assessment (EPA) method which includes deeper levels of the block. At cells was scored as 3+. Nuclear staining intensity was also evaluated and was scored our institution which is a melanoma tertiary care center, we prospectively evaluate the as weak, moderate, or strong. increased sensitivity offered by an EPA method with a protocol for assessment of 5 Results: TdT reactivity was identified in 17/24 (70.8%) of MCC. Staining intensity was HE levels as follows:1,3,5,7,9. variable, but was often moderate to strong and present in a significant percentage of Design: Of 329 malignant melanoma cases with sentinel lymph node biopsies performed cells. Five cases showed 3+ reactivity (reactivity in >50% of cells), three cases showed over the last 2 year period, 44 cases had positive sentinel lymph nodes. The extent of 2+ reactivity (26-50% positive cells), and nine cases showed 1+ reactivity (reactivity in metastasis determined through analysis of numbered levels was used to compare the 1-25% of cells). Of the seven negative cases, three showed rare positive cells (<1% of routine method with the extended method. tumor cells). Expression of TdT was not observed in epidermis, epithelium of cutaneous Results: The rate of micrometastasis detected by EPA over the 2 years was similar to the appendages, endothelial cells, or stromal cells. rate by RPA in the previous 2 years (p = 0.689). In 2 of 42 cases, micrometastasis was Conclusions: Since MCC may have cytomorphologic features similar to lymphoblastic identified only on the later HE levels (EPA method). In the majority of cases, metastasis lymphoma and may present as metastatic , reactivity with TdT in MCC could was present on the RPA levels which were the first three HE levels. represent a diagnostic pitfall in the differential diagnosis with lymphoblastic lymphoma, 92A ANNUAL MEETING ABSTRACTS

Conclusions: An extended pathologic analysis offers a 5% increase in sensitivity in D1 (mean score 2.6 versus 7.6, p=0.05) along with RET (mean score 6.6 versus 10, detection of melanoma metastasis. However, this increase in sensitivity comes with p=0.003) and E-cadherin (mean score 5.8 versus 9, p=0.015) was increased in melanoma. an extra cost of labor and reagents which may be difficult to justify in an era of cost Among primary melanoma. No significant difference was shown between tumors of containment. different thicknesses. Primary versus metastatic melanoma. MSH2/CYCLIN D1 pair can differentiate the groups with 76% accuracy although only CYCLIN D1 (mean score 9 411 P16 Expression in Primary, Recurrent, and Metastatic Merkel Cell versus 5.5, p=0.005) demonstrated statistically significant differences in expression. Carcinomas: A Tissue Microarray Analysis Demonstrating Upregulation Conclusions: Our study indicates that the mismatch repair protein MSH2 expression, when combined with the expression levels of CYCLIN D1 or P16, can reliably EM Cham, TA Victor, KW Lannert, RK Orr, SM Share, TC Pereira, O Lakiza, WB Laskin, differentiate nevi from melanoma. These marker combinations may be useful PM Iannaccone, DO Walterhouse, CD Sturgis. Evanston Northwestern Healthcare, diagnostically and prognostically. Our data also highlights the potential importance of Evanston, IL; Allegheny General Hospital, Pittsburgh, PA; Children’s Memorial MSH2 in melanoma pathogenesis. MSH2 is known to regulate postreplicative DNA Hospital, Chicago, IL; Northwestern Memorial Hospital, Chicago, IL. repair and recently shown to induce cell cycle arrest and apoptosis after DNA damage. Background: Merkel cell carcinomas (MCCs) are rare but aggressive primary cutaneous Further work with more markers should increase the accuracy of differentiating primary neuroendocrine malignancies. Molecular mechanisms in Merkel cell carcinogenesis are from metastatic or low from high grade melanoma. not well understood. P16, a protein product of a cyclin-dependent kinase inhibitor gene, is known to be overexpressed in neuroendocrine tumors and in melanoma; however, few studies of P16 biology have been conducted in MCCs. In this study, we evaluate 414 H2A.X Phosphorylation in Melanocytic Lesions: Expression in P16 expression in a MCC tissue microarray. Malignant Melanoma and Melanocytic Nevi with Severe Architectural and Design: MCC slides and blocks (44 specimens / 39 patients) were retreived from Cytologic Atypia 3 institutions’ archives (ENH 1992-2007, NWMH 2000-2006, AGH 1994-2005). WL Cheung, JM Moresi, GJ Netto. Johns Hopkins Hospital, Baltimore, MD. Nonconsecutive cases included 28 primary, 11 metastatic, and 5 recurrent tumors. Background: Phosphorylation of histone H2A.X at serine 139 (H2A.X-phos) is Patients included 23 (62%) males, 15 (38%) females, and 1 patient for whom history was associated with DNA breaks and plays an important role in recruiting other proteins not available. Mean age at presentation was 71 years (44-94 years). Tissue microarrays involved in DNA repair. Since failure of DNA repair can lead to carcinogenesis, an were created with 3 to 5 cores (0.6 mm) from each MCC. P16 IHC (Biocare Medical, increase of H2A.X phosphorylation, as a surrogate epigenetic marker for DNA break, 1:1000, with antigen retrieval decloaking chamber) was conducted. IHC was scored has been demonstrated in precursor lesions of non-cutaneous malignancies. The current with a semiquantitative three-tiered scale for percent reactivity and intensity. Original study aims at evaluating H2A.X-phos expression in different groups of melanocytic diagnoses and array IHC were confirmed by two pathologists (EMC and CDS). lesions. Results: Strong P16 nuclear reactivity was noted in 89% (25/28) of primary, 100% of Design: Immunohistochemistry was performed using polyclonal antibody for H2A.X- metastatic (11/11), and 100% (5/5) of recurrent MCCs. Three of the primary tumors phos (Upstate Biotech, NY) on parrafin embedded sections from a total of 31 melanocytic showed no reactivity. Strong intensity was seen in 79% (22/28) of primary, 81% (9/11) lesions retrieved from our archives. All original diagnoses were of metastatic, and 100% (5/5) of recurrent cases. confirmed. The 31 cases formed four groups of melanocytic lesions. Group 1 consisted Conclusions: Our data indicate that the majority of primary MCCs and essentially all of 11 invasive malignant melanoma; Group 2: nine melanocytic nevi with severe metastatic and recurrent MCCs overexpress P16, nearly all showing strong intensity. cytologic and architectural atypia; Group 3: six melanocytic nevi with mild cytologic These findings indicate that Merkel cell carcinogenesis may be in part attributed to p16 and architectural atypia/intradermal or compound nevus and Group 4 contained 5 Spitz gene upregulation. As genetic and peptide treatments become available for patients with nevi. All immunostained sections were reviewed by two pathologists on the study. aggressive malignancies, molecules in the p16 pathway may be important therapeutic Results: H2A.X-phos was positive in 9/11 (81%) invasive melanoma (group 1) and targets in patients diagnosed with MCC. 7/9 (77%) melanocytic nevi with severe cytologic and architectural atypia (group 2). In sharp contrast, all remaining lesions in groups 3 and 4 lacked evidence of H2A. 412 Low Affinity Nerve Growth Factor Receptor (P75NGFR) and Perineural X-phos expression including examined melanocytic nevi with mild cytologic and Invasion in Cutaneous Neoplasms architectural atypia, benign intradermal/compound nevi and Spitz nevi. The difference was statistically highly significant (p < 0.0001; Fisher’s exact test). MM Chan, SR Tahan. Beth Israel Deaconess Medical Center, Boston, MA. Conclusions: This is the first study assessing H2A.X-phos expression in different Background: Perineural invasion (PNI) is a well-recognized route of tumor extension classes of melanocytic lesions. Our pilot study reveals that H2A.X-phos expression in cutaneous neoplasms. Despite an established association with increased morbidity appears to be restricted to melanoma and melanocytic nevi with severe cytologic and and frequent local recurrences and metastases, the mechanisms that invoke PNI have architectural atypia. Further studies are needed to confirm the current findings. High yet to be eludicated. We hypothesized that a receptor for nerve growth factors may H2A.X-phos expression in severely atypical and malignant melanomatous lesions be selectively expressed in tumors with perineural invasion. In this study, the P75 could be of diagnostic utility and may further our understanding of the biologic events neurotrophin receptor (P75NGFR) expression was investigated. This nerve growth factor involved in the development of malignant melanoma. receptor is involved in central nervous system function and has been implicated other non-cutaneous tumors with perineural invasion. Design: Immunohistochemical staining for P75NGFR (NeoMarkers, Fremont, CA) was 415 Is Mammaglobin Expression Helpful in Differentiating Mammary performed on forty-seven skin specimens with perineural invasion including invasive from Extramammary Pagets’ Disease and in the Differential Diagnosis of squamous cell carcinomas (SCC=29), basal cell carcinomas (BCC=8), and malignant Pagetoid Neoplasms of the Skin? melanomas (MM=10). P75NGFR expression was compared to similar skin tumors without TL Cibull, BC Gleason, S Badve, BR Smoller, KM Hiatt. University of Arkansas Medical perineural invasion (SCC=7, BCC=7, MM=9) using Fisher’s exact test. School, Little Rock, AR; Indiana University, Indianapolis, IN. Results: P75NGFR staining was not seen in any invasive squamous cell carcinomas Background: Mammaglobin (MGB) protein overexpression was first found in breast irrespective of the presence of perineural invasion (n=0/36). Two basal cell carcinomas carcinoma, with expression present in approximately 50% of tumors seemingly with PNI (n=2/8) and three (n=3/7) without PNI were positive for P75NGFR, most of irrespective of tumor grade, pathologic stage, or HER2 gene amplification status. which showed only focal staining. Interestingly, eight of ten (80%) invasive malignant Originally, MGB overexpression was thought to be restricted to breast carcinoma, but has melanomas with PNI were positive for P75NGFR. This was in contrast to only one of nine since been noted in other malignancies including melanoma, salivary gland tumors, and (11%) melanomas without PNI, P = 0.006. endometrial carcinoma. Skin involvement by breast carcinoma and melanoma can look Conclusions: P75NGFR may be selectively implicated in the pathogenesis of PNI in similar histologically. Both can show a predominantly pagetoid intraepithelial spread of invasive malignant melanomas. Furthermore, its expression may serve as a marker of tumor cells. The purpose of this study was to see if the overexpression of MGB would PNI in melanomas lacking histologic evidence of PNI due to inadequate sampling. be helpful in the histologic differential diagnosis of skin tumors that show intraepithelial pagetoid spread of tumor cells (mammary pagets’ disease (MPD), extramammary pagets’ 413 Expression of MSH2 in Combination with CYCLIN D1 Can disease (EMPD), bowenoid papulosis (BP), and melanoma insitu (MIS)). Distinguish Benign Nevi from Maligant Melanocytic Tumors Design: We searched the archives for cases with the diagnosis of MPD, EMPD, BP, and MIS. Each case was IHC stained with monoclonal mouse anti-human mammaglobin CH Chen, A Rajput, H Feilotter, T Radcliffe, M Akbari, VA Tron. Kingston General clone 304-1A5 (DakoCytomation). Strong diffuse cytoplasmic staining was considered Hospital, Queen’s University, Kingston, ON, Canada; University of British Columbia, positive. If positive the pattern of staining was recorded as (diffuse >10% or focal <10% Vancouver, BC, Canada; Predictive Patterns Software Inc, Kingston, ON, Canada. of neoplastic cells positive). Our control was ductal adenocarcinoma. Background: Melanoma is an increasingly common with a dismal outcome Results: in advanced stages. Tumor thickness and nodal status remain the main prognostic parameters. This study aims at determining protein expression profiles capable of Mammaglobin Expression in Pagetoid Tumors of the Skin Mammaglobin expression (n=# cases) Positive (Diffuse/Focal) Negative predicting tumor progression and to provide information as to the underlying disease MPD (n=13) 1 (Diffuse) 2 (Focal) 10 mechanism. EMPD (n=10) 1(Diffuse) 5 (Focal) 4 Design: Using a melanoma TMA, we investigated 56 melanocytic lesions including 11 BP (n=5) 0 5 benign nevi, 25 primary and 20 metastatic melanoma with relevant clinicopathologic MIS (n=7) 0 7 data. Immunohistochemistry for the following cell cycle regulators, DNA repair proteins mammary pagets’ disease (MPD), extramammary pagets’ disease (EMPD), bowenoid papulosis and signaling molecules was performed on formalin-fixed tissue: CYCLIN D1, MLH1, (BP), melanoma insitu (MIS) MSH2, P16, P53, RET, P-STAT3, CDC27 and PAX3. Immunoexpression was assessed Conclusions: - MGB is expressed less commonly in MPD (23%) than would be expected by two independent evaluators. Statistical analysis included Kruskal-Wallis test, from previous studies of invasive breast carcinoma. Even with diffuse overexpression of Bayesian analysis and Support Vector Machine supervised learning. MGB in underlying breast carcinoma, there was significant loss of expression of MGB Results: Nevi versus melanoma. Combinatorial use of MSH2/CYCLIN D1 could in pagetoid tumor cells. Similar loss of MGB expression has been seen in metastatic distinguish nevi from melanoma with 86% accuracy. The accuracy was increased to breast carcinoma to skin, possibly indicating decreased MGB expression in tumor 91% with additional use of P16 although MSH2 and P16 expression individually did not cells with loss of cell adhesion and gain of metastatic ability - MGB is not helpful in show statistical significance. On the other hand, the individual expression of CYCLIN ANNUAL MEETING ABSTRACTS 93A the differential diagnosis of skin tumors showing an intraepithelial pagetoid spread of with the DIF and LM findings. The C3d and C4d methodologies have been previously tumor cells - MIS did not show overexpression of MGB, which is in contrast to previous published. studies reporting overexpression in melanomas. Results: All discoid lupus erythematosus (DLE)(11/11) and systemic lupus erythematosus (SLE)(4/4) cases showed prominent granular C3d along the dermal 416 Cdc7 in Melanomas, Spitz Tumors, and Melanocytic Nevi epidermal junction (DEJ) and a positive lupus band test (LBT) by DIF. Additionally, all SLE cases demonstrated granular DEJ C4d with C3d or C4d in blood vessels (BV). LE Clarke, J Hennessy, TJ Fountaine, RD Bruggeman, JT Clarke, KF Helm. Penn State Only 1 DLE case showed DEJ C4d. All subacute lupus erythematosus (SCLE) cases Hershey Medical Center, Hershey, PA. (10/10) lacked DEJ C3d and C4d; none had a positive LBT by DIF. C4d within epidermal Background: Malignant melanoma is a lethal cutaneous neoplasm that may exhibit keratinocytes was seen in some SCLE (3/10), corresponding to IgG by DIF and anti-Ro histopathologic overlap with Spitz nevi and other benign melanocytic lesions. Evidence antibodies. Drug induced cases showed C3d and C4d in BV. Dermatomyositis (DM) suggests abnormalities in cell cycle regulation promote melanoma progression. Cdc7 showed C3d and C4d in BV corresponding to C5b-9 in BV by DIF (11/11). 45% showed is a serine-threonine kinase required for initiation of DNA replication that has been DEJ C3d, none had DEJ C4d, differing from SLE. No DM case had a positive LBT shown to be overexpressed in melanoma cell lines with defects in the DNA damage G1 albeit all had prominent DEJ C5b-9. Pemphigoid cases displayed homogenous DEJ C3d checkpoint. The purpose of this study was to evaluate expression of Cdc7 in a wide range (12/14) while C4d was characteristically negative, with 100% concordance with linear of melanocytic neoplasms by immunohistochemical methods on routinely processed IgG and C3 by DIF. Of 9 cases, 80% demonstrated intercellular C3d and formalin-fixed parrafin-embedded tissue in tissue microarrays. C4d, mirroring intercellular IgG and C3 on DIF. Porphyria showed homogeneous and Design: Tissue microarrays containing triplicate samples of 100 melanocytic neoplasms granular C3d and C4d (9/9 C3d; 6/9 C4d), mirroring Ig and C5b-9 in BV by DIF. IgA were constructed. Included were 33 melanomas, 39 Spitz nevi (including a group of vasculitis exhibited prominent C3d and C4d (4/4) in BV, corresponding to complement ‘atypical’ Spitz nevi), and 28 benign nevi of other types. Immunohistochemistry was and IgA in BV by DIF. Two relapsing polychondritis cases showed C3d and C4d within performed on 5-um sections using a monoclonal mouse antibody (SPM 171, Abcam). chondrocyte nuclei, in contrast to negative staining chondrodermatitis nodularis helicus Only crisp nuclear staining was considered positive. Staining was scored semi- (2/2). 30 cases with a nonspecific DIF profile were negative for C3d and C4d. quantitatively according to intensity as none (0), weak (1), and moderate-strong (2), Conclusions: C3d and C4d by IH largely mirror the DIF profile. When correlated with and according to extent as none (0), 0- 2% (1), 2-10% (2), and >10% (3). To correlate LM and clinical findings, C3d and C4d may provide useful diagnostic information, extent and intensity of immunopositivity, values were converted into composite scores by adding to morphologic assessment. It may prompt further DIF testing or in some multiplying scores of extent by intensity. The differences between groups were analyzed instances, may even define a reasonable substitute for DIF. using the t test (2-sided). All P values < 0.05 were considered significant. Results: Overall, 55% of melanomas (all types), 72% of Spitz nevi, and 39% of benign nevi expressed Cdc7. Positivity was greatest within the dermal components of the 419 Is Immunohistochemical Analysis of DNA Mismatch Repair Spitz nevi and melanomas. Composite scores differed significantly between malignant Proteins in Unselected Sebaceous Neoplasms Warranted as a Screening melanoma and benign melanocytic nevi (P < 0.001) but not between melanoma and Test for Muir-Torre Syndrome? Spitz nevi (P = 0). When the group of atypical Spitz nevi were excluded, the difference ZP Elaba, D Mandich, RW Cartun, S Ligato. Hartford Hospital, Hartford, CT. approached statistical significance P( = 0.059). Background: Muir-Torre syndrome (MTS) is an autosomal-dominant genodermatosis Conclusions: Cdc7 expression differs significantly among cutaneous melanocytic defined as the combined occurrence of at least one sebaceous gland neoplasm, or neoplasms and can be evaluated by routine immunohistochemical methods. The results keratoacanthoma, in conjunction with an internal malignancy. The majority of cases suggest abnormalities of the DNA damage G1 checkpoint are involved in the progression of MTS are caused by germline mutations in the DNA mismatch repair (MMR) genes of melanocytic lesions and may account for some of the differences between malignant MSH2 or MLH1. Early identification of this syndrome is important because skin melanomas and benign melanocytic nevi. lesions usually precede internal neoplasms. The aim of this study was to evaluate if the immunohistochemical expression of MHL1 and MSH2 in unselected sebaceous 417 Real Time RT-PCR Based Detection of Prognostic Markers in neoplasms is a useful screening method for the detection of MTS in the general Primary Melanoma from Paraffin-Embedded Tissue population. Design: Thirty-two sebaceous neoplasms (18 sebaceous adenoma, 6 sebaceous E Duncavage, R Jarrett, ML Council, A Lind, J Pfeifer. Washington University, St. epithelioma, 4 sebaceous carcinoma, 1 adnexal neoplasm with sebaceous differentiation, Louis, MO. 1 squamous cell carcinoma with sebaceous differentiation and 2 basal cell carcinoma Background: While histologic factors such as Breslow thickness, Clark’s level, with squamous and sebaceous differentiation) were identified. Immunohistochemical ulceration, and mitotic rate are associated with metastatic potential in primary staining for DNA MMR proteins (MLH1, MSH2, MSH6 and PMS2) was performed melanomas, they cannot fully predict disease outcome or suggest specific molecular on formalin-fixed, paraffin-embedded tissue. Clinical information was then collected treatment targets. For our analysis, we chose 10 genes previously reported to be highly to identify occurrence of internal malignancies in these subjects. correlated with metastatic dissemination of cutaneous melanoma in microarray-based Results: Loss of expression of MMR proteins was identified in 7/32 cases (22%), with studies of fresh frozen specimens. loss of MSH2 in 6/7 and MLH1 in1/7 cases. Eight (25%) of the 32 cases had at least Design: We identified a set of 16 patients with primary melanoma. For each patient, 1 internal malignancy associated with the sebaceous neoplasm, fulfilling the clinical paraffin-embedded tissue (PET) representing the primary tumor was present in our criteria for MTS. Of these 8 cases, 5 (62%) showed loss of expression of MMR proteins. files. The patient cohort represented a range of stages at presentation: 4 presented Three cases (9%) with both sebaceous neoplasm and internal malignancy did not show with T1 tumors, 2 with T2 tumors, 3 with T3 tumors, and the remaining 7 with T4 any loss in either MSH2 or MLH1 expression. tumors. All patients underwent sentinel lymph node (SLN) examination; 10 had SLN Conclusions: Loss of expression of MMR proteins was identified in 22% of an metastases. 9 of the 16 patients were living as of 7.17.07; the overall average follow- unselected population with sebaceous neoplasm and in 62% of cases of sebaceous up was 37 months. Exon-spanning primers with amplicon lengths between 80-120 bp neoplasm with associated internal malignancy. These findings are highly suggestive were constructed based on referenced GenBank sequences. RNA was extracted from of MTS and should be followed up with confirmatory molecular genetic tests. In our 10µm sections of primary resection specimens and analyzed using Aglient NanoRNA opinion, patients with a sebaceous neoplasm should be offered testing for microsatellite chips. Gene expression was measured in duplicate using a one-step SYBR green based instability by immunohistochemical analysis as a screening test for MTS. RT-PCR chemistry on an ABI 7300 instrument. Amplicon identity was confirmed by melting curve analysis. Results: We analyzed a total of 708 RT-PCR reactions, including controls. Gene 420 Differential Nuclear Patterns of BMI-1 Expression in Melanomas expression values were normalized to β-actin expression. Statistical significance was and Benign Nevi calculated using the SAS software package. While the expression levels of all selected RR Fortna, T Pasha, R Elenitsas, X Xu. University of Pennsylvania, Philadelphia, genes, including CDC2, FDG3, KPNA2, MCM4, MELK, NME1, PROM2, PTGDS, PA. RFC4, and SLUG, were correlated with melanoma recurrence, only MELK, a serine/ Background: Recent evidence suggests that melanomas, like some other malignancies, threonine kinase, approached statistical significance (p=.05). When T stage was taken contain a population of “tumor stem cells” which may drive tumor proliferation. BMI- into account, none of the selected genes provided additional prognostic information. 1, a transcription factor that negatively regulates expression of the Ink4a/Arf locus, is Conclusions: Using methods optimized to detect gene expression in archival PET, we necessary for self-renewal of normal stem cells and has recently been implicated in were unable to show a significant correlation between expression of selected genes self-renewal of tumor stem cells in certain malignancies. and outcome in our limited data set. However, we have shown that it is possible to Design: An immunohistochemical analysis of BMI-1 in melanomas and nevi was reliably detect gene expression in routine PET melanoma specimens. By adding more performed. We used an area-averaged four-point (0+ to 3+) scoring system to measure patient samples to our data set, we hope to strengthen the statistical significance of overall nuclear expression and an area-averaged five point (0+ to 4+) scoring system these findings. to measure prevalence of nuclear “speckles.” Two-tailed Student’s t-Test was used for statistical analyses. 418 The Use of C3D and C4D as a Diagnostic Adjunct in the Assessment Results: Both melanomas and nevi expressed nuclear BMI-1, with no statistical of Non-Neoplastic Skin Disease difference between the two (scores 1.50 ± 0.48 for melanomas (n=7) and 1.89 ± 0.54 for nevi (n=17); p=0.11). An unusual nuclear “speckle” pattern was noted in melanomas, ME Dyrsen, PA Chadwick, CM Magro. Weill Cornell Medical College, NY, NY. superimposed on the background nuclear staining. It consisted of ∼1 to 5 tiny (1-2 Background: Direct immunofluorescent (DIF) testing is an important adjunct in µm in diameter), intense foci of BMI-1 within the nucleus, which did not colocalize classifying inflammatory skin conditions. While advances have been made in applying with the nucleolus. The pattern was distinctly more prominent in melanomas than in antibodies to tissue, there has been no reported success of immunohistochemistry (IH) as nevi. Other cell types expressing BMI-1 did not show this pattern, and it has not been a potential substitute for cutaneous DIF testing. C3d and C4d are stable components of described in other tumor types. We scored the samples and found a distinctly higher complement activation. We used C3d and C4d IH on paraffin embedded formalin fixed prevalence of the pattern in melanomas than in nevi (scores 3.51 ± 0.50 for melanomas tissue as a potential diagnostic adjunct in evaluating inflammatory skin . (n=7) and 1.09 ± 1.00 for nevi (n=17); p<0.0001). When nevi were subdivided into Design: A natural language search identified cases submitted for both light microscopic dysplastic and non-dysplastic types, the nuclear speckle pattern remained clearly more (LM) and DIF studies, from 7/06-8/07. We correlated the C3d and C4d staining pattern prevalent in melanomas than in either dysplastic nevi (score=1.42 ± 1.05; p<0.0003, 94A ANNUAL MEETING ABSTRACTS n=11) or non-dysplastic nevi (score=0.50 ± 0.58; p<0.0001, n=6). The pattern appeared 423 CD25 Expression in Cutaneous Mast Cell Lesions: Differential somewhat more prominent in dysplastic than in non-dysplastic nevi, although this Expression in Cutaneous and Systemic Mastocytosis difference did not reach statistical significance (p=0.069) with the number of samples JL Herrick, LA Erickson, TJ Flotte. Mayo Clinic, Rochester, MN. analyzed to date. Background: Mastocytosis is a heterogeneous disorder that may affect the skin alone Conclusions: BMI-1 is expressed in both melanomas and nevi, but a unique nuclear or may affect other organs. CD25, the alpha subunit of the IL-2 receptor, has been speckle pattern of expression is distinctly more prominent in melanomas than in nevi. studied in systemic mastocytosis where it is a marker of aberrency, but has not been This pattern may be diagnostically useful in differentiating benign and malignant evaluated in cutaneous mast cell lesions. We analyzed a series of 21 patients with melanocytic lesions. Further investigation of the identity of these speckles may cutaneous mast cell lesions. also provide insight into a possible role for BMI-1 in melanocytic dysplasia and Design: Formalin-fixed paraffin embedded tissues from 21 patients with cutaneous tumorigenesis. mast cell lesions, including 5 mastocytomas, 6 cases of telangectasia macularis eruptiva perstans, and 10 cases of urticaria pigmentosa, were analyzed immunohistochemically 421 Diagnosis of Mycosis Fungoides with Different Algorithmic with antibodies to CD25. Immunoreactivity was graded semiquantitatively from 0 Approaches to 3+. The results were correlated with the patients’ clinical follow-up information PS Furmanczyk, GM Wolgamot, SJ Kussick, DE Sabath, JE Olerud, ZB Argenyi. regarding systemic involvement, as well as, bone marrow studies and serum University of Washington, Seattle, WA; Northwest Pathology, Bellingham, WA; tryptase levels. Phenopath Laboratories, Seattle, WA. Results: Follow-up information showed 11 of the patients manifested systemic mast Background: The diagnosis of early mycosis fungoides (MF) is difficult due to cell disease while 10 patients had mast cell disease limited to the skin. Increased CD25 overlapping histopathologic features with benign dermatoses. Several studies have expression was identified in the cutaneous lesions of patients with systemic mast cell evaluated specific approaches to aid in making this diagnosis, including grading systems disease as compared to those of patients with mast cell disease limited to the skin. scoring specific histologic features, panel scores to increase diagnostic consistency, and Cutaneous mast cell lesions in patients with systemic mastocytosis showed greater most recently, an International Society for Cutaneous Lymphoma (ISCL) algorithm expression of CD25 (8 of 11 cases showed 2+ or 3+ CD25 staining), than cutaneous incorporating clinical and histologic findings with ancillary testing. At the UWMC, lesions from patients with cutaneous mast cell disease only (2 of 10 cases showed 2+ at the clinicians discretion, cases of suspected MF are submitted individually to 5-6 or 3+ staining for CD25). pathologists for scoring, from which an average panel score is combined with the clinical Conclusions: The intensity of aberrant expression of CD25 in cutaneous mast cells impression to reach a diagnosis. The purpose of this study is to retrospectively compare within mastocytosis correlates with the extent of disease. these different diagnostic approaches. Design: The pathology files at UWMC were reviewed for cases from a referral 424 Acute Generalized Exanthematous Pustulosis: A Clinical and clinic in which MF was in the clinical differential. The biopsies were Histologic Study of Forty-Five Cases evaluated using 3 different approaches: 1) histologic grading based on the system MP Hoang, M Mahalingam, J Bhawan, P Kapur, WA High. Massachusetts General proposed by Guitart et al; 2) review by an MF panel; and 3) application of the ISCL Hospital, Boston, MA; Boston University Medical School, Boston, MA; UT scoring system, which included immunohistochemical evaluation of CD3, CD20, Southwestern Medical Center, Dallas, TX; University of Colorado Health Sciences CD2, CD5, and CD7. Center, Aurora, CO. Results: A total of 81 cases were evaluated. Clinical follow-up averaged 31.2 months Background: Literature on acute generalized exanthematous pustulosis (AGEP) is on 68% of cases, while the other 32% of cases had < 6 months of follow-up. Subsequent restricted to case reports with only one prior series. clinicopathologic diagnosis of MF was made in 37 cases (49% stage IA/IB). An MF panel Design: We evaluated the clinical features of 45 AGEP cases and compare their histologic score was available in 40 cases. The Guitart et al grading system for categorized features to those of 19 cases of pustular psoriasis. cases with a subsequent clinicopathologic diagnosis of MF as follows: 41% MF; 43% Results: Patients with AGEP ranged in age from 12 to 91 years (mean, 53 years) with a suggestive of MF; 8% cannot exclude MF; 8% not MF. For cases with a panel score; M:F=4:3. All 45 patients presented with a generalized erythematous, pustular eruption 81% of MF cases had an avg score >2.0 (consistent with MF). An ISCL clinical score (mean duration of pustules, documented in 17 patients, 12 days) and fever (latter in could be assigned in 42 cases. Of these, 22 had a total score of at least 3 (4 required for 25/31, 81%). History of recent drug intake was documented in 36/38 (95%) patients and MF) utilizing clinical, histologic and IHC findings (77% with a diagnosis of MF). IHC 13 of whom had a prior drug reaction. Of the five pediatric cases, two had prior URI and showed loss of CD7, CD5 or CD2 in 22 cases (68% of which were MF cases). no history of recent drug ingestion. None had a history of psoriasis. Histologic features Conclusions: The diagnosis of MF is difficult resulting in different approaches; of AGEP vs. pustular psoriasis are summarized in the Table below. therefore, comparison of the currently available methods could resolve their inherent AGEP Pustular psoriasis P value limitations. N 45 19 Parakeratosis with neutrophils and serum 7/45 1/19 NS Parakeratosis with neutrophils 4/45 16/19 0.002 422 p63 Is Specific for Spindle Cell Squamous Cell Carcinoma in Subcorneal pustules 45/45 18/19 NS the Differential Diagnosis with Atypical Fibroxanthoma Intraepidermal pustules 40/45 18/19 NS BC Gleason, TL Cibull, KB Calder, MB Morgan, AB Thomas, SD Billings, KM Hiatt, Eosinophils within pustule 14/45 1/19 0.03 BR Smoller. University of Arkansas for Medical Sciences, Little Rock, AR; University Epidermal spongiosis 45/45 14/19 0.0002 Acanthosis 44/45 19/19 NS of South Florida College of Medicine, Tampa, FL; Cleveland Clinic Foundation, Psoriasiform hyperplasia 8/45 9/19 0.01 Cleveland, OH. Basal mitoses (>1/10HPFs) 30/43 11/19 NS Background: The histologic differential diagnosis of atypical spindle cell neoplasms Exocytosis of eosinophils 16/45 1/19 0.01 arising in sun-damaged skin primarily includes atypical fibroxanthoma (AFX), spindle Necrotic keratinocytes 41/45 1/19 0.004 cell squamous cell carcinoma (SCSCC) and spindle cell melanoma. While spindle papillary dermal edema 43/45 7/19 0.006 Vasculitis 0/44 0/18 NS cell melanoma is readily differentiated by reactivity for S100, AFX and SCSCC can Fibrinoid 1/44 0/18 NS be difficult, if not impossible, to distinguish in some cases, as keratin expression in Extravasation of erythrocytes 42/45 10/19 0.006 SCSCC may be focal or absent and no reliable marker for AFX has been identified. Follicular involvement 4/45 1/19 NS p63 is normally expressed in the basal and lower spinous layer keratinocytes and is Dermal eosinophils (>1+) 19/44 0/18 0.0004 widely used as a marker for poorly differentiated SCC. As normal mesenchymal cells Dermal neutrophils (>1+) 25/44 6/18 NS Dermal lymphoocytes (>1+) 25/44 12/18 NS do not express p63, this antibody may be helpful in the distinction between SCSCC and AFX. Previous studies have shown that p63 is a sensitive marker for SCSCC, but Conclusions: Our findings support the theory that the majority of adult AGEP cases the immunoreactivity of p63 in a large series of strictly defined AFXs (see below) has are drug induced while in pediatric AGEP, and drug appear to be equally not been investigated. implicated. Salient histologic features of AGEP include: eosinophilic pustulosis, Design: The files of 3 institutions were searched for AFXs that satisfied the following spongiosis, eosinophilic exocytosis, necrotic keratinocytes, papillary dermal edema, criteria: 1) origin in sun-damaged skin; 2) complete excision with negative margins (on extravasation of erythrocytes and dermal eosinophils. Given that these parameters are this or a subsequent specimen) in order to evaluate the entire lesion, including the deep significantly reduced/absent in pustular psoriasis, an awareness of these will likely margin; 3) no extension into subcutaneous tissue; 4) no reactivity for AE1/AE3, CAM5.2, increase diagnostic accuracy of AGEP. CK5/6 or S100; and 5) no overlying epidermal dysplasia, necrosis, perineural invasion or lymphovascular invasion. Immunostains for p63 were performed on 20 AFXs meeting 425 High-Grade Atypical Melanocytic Nevi Show Kinetic and these criteria. For comparison, 6 SCSCCs were stained for p63 and all 3 keratins. Microsatellite Features of Progression at the Junctional Compartment Results: All 20 AFXs were negative for p63. Interestingly, 2 additional cases diagnosed EA Husain, L Pozo, A Blanes, SJ Diaz-Cano. Homerton University Hospital, London, as AFX on shave biopsies showed strong, multifocal nuclear positivity for p63. However, United Kingdom; University of Malaga School of Medicine, Malaga, Spain; King’s during review of the excision specimens, extensive involvement of the subcutaneous College Hospital, London, United Kingdom. tissue was noted in these 2 cases, excluding the diagnosis of AFX. All 6 SCSCCs were Background: Atypical (dysplastic) melanocytic nevi (AMN) are heterogeneous positive for p63. lesions considered precursors of malignant melanomas (MM). No cell kinetic, cell Conclusions: Prior studies have shown that p63 is a sensitive marker for SCSCC. cycle regulators and microsatellite profile analyses by topographic compartments are Our study supports this finding and further suggests that p63 is specific marker for available. SCSCC in the differential diagnosis with AFX, if the latter is strictly defined. Although Design: We selected 133 lesions, classified into low-grade AMN (92), high-grade AMN it is unknown whether tumors that express p63 in the absence of keratins represent (31), and MIS (10), using standard criteria. Regular melanocytic nevi (15 junctional, 20 immunophenotypically aberrant SCSCCs, in our experience, p63 reactivity argues compound) and MM (15 radial growth phase and 27 vertical growth phase) were used against the diagnosis of AFX. as controls. The microsatellite patterns of TP53, INK4a (p16), p21WAF1, and p27KIP1 were studied by PCR-capillary electrophoresis after topographic microdissection (junction, superficial and deep dermis) and DNA extraction. The same areas were studied for the expression of Ki-67, p53, p21WAF1, and p27Kip1, and scored by topographic ANNUAL MEETING ABSTRACTS 95A compartments. Apoptosis was studied by the in situ end labeling (ISEL) of fragmented MSH2 and MSH6 was observed. No internal carcinoma was found in these patients. In DNA. The results were compared using analysis of variance and Student t-test, and 11 sebaceous tumors a strong expression of all of three proteins was seen. MSH2 gene considered significant if P<0.05. analysis revealed three patients harboring the same alterations in position IVS10+6 Results: Benign melanocytic lesions and low-grade AMN revealed sporadic p16 (T>C). IVS10+12 (A>C) has been found in two of these patients. Moreover, a possible microsatellite abnormalities at the junction only, while MM shows coexistent splicing donor in position IVS12+2 (T>A) was detected in one of these patients.In other microsatellite abnormalities (p16, p27) and no topographic gradient. High-grade AMN patient, we found within the exon 13 at position IVS13-1 (G>C) a possible slicing revealed coexistent microsatellite abnormalities of p53, p16, and p27 in 40%. All acceptor. MLH1 analysis did not show any alteration. markers immunoexpression decreased from intraepidermal to dermal compartments, Conclusions: It is postulated that the immunohistochemical analysis of mismatch repair whereas increased with the degree of atypia in AMN. Ki-67 was mainly restricted to proteins can be a useful tool in the evaluation of skin sebaceous tumors in the diagnosis the junction in high-grade AMN, whereas no significant differences by compartments of MTS syndrome. These molecular alterations may be correlated with the loss of the were detected in low-grade AMN. P53 immunoexpression was significantly higher MSH2 proteins and indicate a new phenotypic group of Muir-Torre patients. in high-grade AMN and MIS and revealed and inverse correlation with p21 and p27 expression. Significantly decreased expression was observed in invasive MM (12.09%). 428 MFG-E8 Expression in Malignant Melanoma and Benign ISEL index was significantly lower at the junctional compartment of high-grade AMN Melanocytic Nevi (2.21% vs. 4.01% at dermal one). No significant differences were observed for ISEL MM Johnson, NA Belsley, M Jinushi, DR Carrasco, G Dranoff, MC Mihm. Massachusetts index by compartments in low-grade AMN. General Hospital, Boston; Beth Israel Deaconess Hospital, Boston; Dana-Farber Cancer Conclusions: High-grade AMN accumulates microsatellite abnormalities of TP53 and Institute, Boston. cell cycle regulators (p21WAF1 and p27KIP1), along with abnormal p53 expression Background: Milk fat globule-EGF 8 (MFG-E8), also know as lactadherin, is a only. In contrast, invasion in MM seems to be TP53-independent and conventional nevi phosphatidylserine-binding protein that opsonizes apoptotic cells to facilitate phagocyte and low-grade AMN show low incidence of cell cycle regulator abnormalities. engulfment via the αvβ3 and αvβ5 integrins, one of which (αvβ3) is expressed by melanoma cells in vertical growth phase. MFG-E8 has been shown in animal models 426 Preserved Topographic Gradient of Cell Cycle Regulator to play important roles in mammary gland involution, immunoregulation, angiogenesis, Microsatellites Abnormalities and Regressive Cell Kinetics Characterizes and fertilization, and its expression has been documented in a number of different Spitz Tumors murine cancer cell lines, including melanoma. It has therefore been hypothesized that EA Husain, L Pozo, A Blanes, SJ Diaz-Cano. King’s College Hospital, London, United MFG-E8 may play a role in tumorigenesis. We sought to investigate MFG-E8 expression Kingdom; Homerton University Hospital, London, United Kingdom; University of patterns in human melanomas. Malaga School of Medicine, Malaga, Spain. Design: We evaluated MFG-E8 expression in 11 vertical growth phase melanomas and Background: Cell kinetics and microsatellite profile of cell cycle regulators by 5 compound melanocytic nevi by immunohistochemistry. The melanomas included topographic compartments remain unknown in Spitz tumors (ST). No study has examples of nodular (5), superficial spreading (2), acral lentiginous (2), lentigo maligna correlated simultaneously these variables. (1), and unclassified (1) types. We classified staining based on pattern (cytoplasmic, Design: We selected ST (42, all B-RAF-negative), malignant melanomas (42, 15 radial membranous, and perinuclear), intensity (0-3+), location (superficial, deep, or diffuse), growth phase MM-RGP and 27 vertical growth phase MM-VGP), and conventional and volume (percentage of tumor cells stained). Histologic features including mitotic melanocytic nevi (15 junctional, 20 compound), the latter two groups used as controls. rate and presence or absence of tumor-infiltrating lymphocytes were examined, and The microsatellite patterns of TP53, INK4a (p16), p21WAF1, and p27KIP1 were sentinel lymph node status was included where available. studied by PCR-capillary electrophoresis after topographic microdissection (junctional, Results: MFG-E8 expression was significantly higher in melanomas than in compound superficial and deep dermal) and DNA extraction. The same areas were systematically nevi (8/11 versus 1/5, p=0.04877). Melanomas expressing MFG-E8 included all studied for the expression of Ki-67, p53, p21WAF1, and p27Kip1, and scored by examples of nodular and superficial spreading types as well as the unclassified case, topographic compartments, screening the whole compartment in each case. CD-31- with no expression seen in the cases of acral lentiginous or lentigo maligna melanoma. stained slides were used to estimate microvessel density. The results were statistically Percentage of cells staining varied from <5% to 90%, with an average of 40%. Staining compared using analysis of variance and Student t-test, and considered significant if patterns were variable, and intensity ranged from 2-3+. Staining was diffuse in 5 cases, P<0.05. Appropriate controls were run in each case. deep in 2, and superficial in 1. There was no correlation between MFG-E8 expression Results: Microsatellite abnormalities were heterogeneously distributed in ST (maximum and mitotic rate, tumor-infiltrating lymphocytes, or sentinel node status. incidence for p16, 50%) but predominate in junctional compartments and did not show Conclusions: MFG-E8 expression was significantly higher in melanomas than in coexistent microsatellite abnormalities. Benign melanocytic lesions revealed sporadic benign melanocytic nevi, and was only present in certain tumor types. Its relationship p16 microsatellite abnormalities at the junction only, while MM shows coexistent to αvβ3 and αvβ5 suggests that further investigation into MFG-E8 function in melanoma microsatellite abnormalities (p16, p27) and no topographic gradient. Superficial-to-deep and inquiry into its relationship with cell surface adhesion molecules and angiogenesis gradient was maintained for Ki-67 in all lesions, but was significantly higher in MM. are warranted. No differences in p53 immunoexpression were detected. ST revealed reverse pattern with significantly overexpressed p21WAF1 and p27Kip1 and increased microvessel 429 Elastin Immunostain Distinguishes the Elastic Fiber Network in density at the deep dermal compartment (Table). Malignant Melanomas with Regression from Melanomas with Scarring ST and MM: Kinetics and microvessel profile Fibrosis Spitz Tumors MM-RGP MM-VGP Ki-67 (%) 5.49 22.89 36.9 H Kamino, S Tam, S Toussaint. New York University School of Medicine, New York, p53 (%) 5.58 4.24 9.56 NY; Hospital Manuel Gea Gonzalez, Mexico, DF, Mexico. p21-WAF1 (%) 20.73 -- 9.18 Background: Partial regression has been reported in 10% to 5% of invasive p27-KIP1 (%) 52.76 -- 4.42 melanomas. Although, histopathologic identification of regression is usually easy, in CD31 (uvess/HPF) 7.42 2.58 4.89 some cases it can be difficult to distinguish regression from scarring fibrosis secondary Conclusions: STs (in contrast to MM) reveal preserved microsatellite and kinetic to a previous surgical procedure. In this study, we compare the elastic fiber pattern in gradient and an overall regression profile (low proliferation and over-expression of pro- melanoma with regression to the pattern in melanomas with scarring fibrosis. apoptotic molecules). The microvessel pattern is inefficient to maintain cell proliferation Design: We studied the elastic fiber network in 33 invasive melanomas with the and has been demonstrated independent of the kinetic profile, in contrast to MM. fibrosing stage of regression. None had a prior surgical procedure. For comparison, we studied ten cases of invasive melanomas with scarring fibrosis due to prior surgery. 427 The Value of Skin Sebaceous Gland Tumors in the Diagnosis of The Breslow thickness in both groups ranged from 0.4 mm to 3.4 mm. The elastic fiber Muir-Torre Syndrome by Immunohistochemical and Molecular Evaluation pattern was evaluated with elastic van Gieson (EVG) stain and elastin immunostain. of MLH1, MSH2 and MSH6 Genes For baseline control, we used the elastic tissue network from non-lesional skin adjacent M Idoate, R Zarate, A Cordoba, I Sanchez-Carpintero, M Robles, J Echeveste, T Tunon, to the melanoma. J Garcia-Foncillas, MD Lozano, A Panizo. University of Navarra, Pamplona, Navarra, Results: The elastic tissue network was better visualized with the elastin immunostain Spain; Navarra Hospital, Pamplona, Navarra, Spain. than with the EVG stain. All 33 cases of melanoma with regression showed markedly Background: Sebaceous tumors are rare neoplasms frequently associated with Muir- decreased density to absence of elastic fibers in the areas of fibrosis. At the base of Torre syndrome (MTS). The mutation of mismatch repair genes correlates strongly the regression, a layer of compressed thin elastic fibers, normally seen in the papillary with the lack of expression of the correspondent proteins. To evaluate the utility of dermis, appeared pushed down by the fibrosis into the reticular dermis. This pattern immunohistochemical analysis of mismatch repair proteins in the diagnosis of MTS was similar to that seen at the base of non-regressed invasive areas of melanoma. In a series of patients diagnosed of sebaceous skin tumors have been included in the melanomas on sun-damaged skin, thicker elastotic fibers and globules were also seen at study. the base of the regression. In the ten cases of melanoma with a surgical scar, elastic fibers Design: A retrospective clinico-pathological review of 24 skin sebaceous tumors of 21 were also absent to decreased in areas of fibrosis. At their base there were thick, coarse, patients (range 55-97 years) diagnosed during the period 1996-2007. In all cases a chart branched elastic fibers oriented parallel to the skin surface, which are characteristic of review was realized. An immunohistochemical study of all biopsies was performed the level of the spared reticular dermis. using monoclonal antibodies against MLH1, MSH2, MSH6 (Biocare Medical) using Conclusions: We recognized different patterns of elastic fibers found at the base of an amplification method from Novocastra. Direct sequencing of purified PCR products regression of melanoma compared to the base of melanomas with a surgical scar. The of MLH1 and MSH2 genes was performed. elastin immunostain was superior to the EVG stain in visualizing these patterns. These Results: All tumors were located in the face or scalp. In 8 conventional sebaceous findings can be helpful in distinguishing the fibrosing stage of regression from scarring tumors (6 adenomas, 1 carcinoma, and 1 nevus) from 5 patients a lack of expression fibrosis, a common pitfall in evaluating melanomas. of both MSH2 and MSH6 was observed. In all of these patients a visceral carcinoma had been diagnosed previously. In the other hand, in 5 sebaceous tumors (4 adenoma and 1 carcinoma) from same number of patients lack of expression of either MLH1 or 96A ANNUAL MEETING ABSTRACTS

430 FoxP3+ CD4+ T Regulatory Cells and Survival in Melanoma staining to control slides, with diffuse cytoplasmic staining and complete membrane H Kamino, R Walters, S Tam, H Ratech. New York University School of Medicine, New staining. For a case to be called positive, more than 1% of the tumor cell population York, NY; Albert Einstein Medical College, Bronx, NY. had to stain. Overall percent staining was estimated by A) total proportion of melanoma Background: A specialized subset of CD4+ T cells known as T regulatory (T-reg) cells staining with the aforementioned criteria and B) Proportion of melanoma cells cells can infiltrate tumors and suppress tumor-specific cytotoxic CD8+T cell responses, staining positive by the same criteria in the vertical growth phase alone. thereby inhibiting tumor rejection. T-reg cells constitutively express FoxP3, a member Results: 1. Nevi retained very high levels of c-kit expression (89%). 2. The total of the forkhead family of transcription factors. It has been suggested that CD4+/CD25+/ number ALM staining positive was 76% in our population, which had a much higher FOXP3+ T-reg cells induce immunotolerance during early melanoma genesis, favoring Asian/Pacific Islander representation compared to prior studies. 3. C-kit expression melanoma growth, because there is a higher percentage of T-reg cells in the radial growth was the highest in the junctional component for both nevi and ALMs. As the ALM phase than in the vertical growth phase of melanomas. We investigated the relationship became nodular, c-kit expression diminished to 31%. This vertical component is the between T-reg cells and survival in patients with melanoma of different thicknesses. most likely to metastasize. Design: Tissue sections of 44 cases of invasive melanoma were immunohistochemically Conclusions: Presently, systemic treatments have had a negligible impact on overall stained for FoxP3. The positive cells were counted using a 10x10, 1 mm2 grid in a survival for advanced stage melanomas. Previous clinical trials investigated the use 10x ocular combined with a 40x objective in an Olympus BX41 . In each of imatinib mesylate as a targeted molecular therapy for patients with metastatic tissue section, 5 areas were counted both within the tumor and at the tumor-stromal malignant melanoma, however it was found to be ineffective. It was later noted that interface. The mean FoxP3+ cell counts were analyzed with respect to patient survival these trials were conducted with a majority non-ALM patients that expressed normal, and tumor thickness. or reduced levels of c-kit. Our study shows that a large percentage of ALM have c-kit Results: The melanoma thickness ranged from 0.87 to 5.4 mm. The survival ranged expression, and further clinical trials with ALM patients utilizing imatinib mesylate from 6 to 220 months. Eleven patients died with disease. There was no correlation should be considered. between the total number of FoxP3+ cells and tumor thickness or between the total number of FoxP3+ cells and overall survival. However, there were about 2.5 times as 433 Expression of Mineralocorticoid Receptor and 11β-Hydroxysteroid many FoxP3+ cells at the tumor-stromal interface compared to those within the tumor Dehydrogenase Type II in Cutaneous Adnexal Neoplasms: A Tissue -9 (24.84 vs. 9.59; T-test, p=1 x 10 ). Microarray Study Conclusions: Although the distribution of FoxP3+ cells varies between the tumor and AC Laga, E Yakirevich, DJ Morris, R Tavares, L Noble, RA DeLellis, MB Resnick. Alpert the interface in invasive melanomas, we did not find any predictive value for survival. Medical School of Brown University, Providence, RI. Possibly, T-reg cells are not significant in the tumor progression of malignant melanoma. Background: The skin is an important target for mineralocorticoids. Aldosterone, the Alternatively, a larger sample size might be required to demonstrate an effect of FoxP3+ main endogenously secreted mineralocorticoid, binds to mineralocorticoid receptors cells on survival. (MR) in sweat glands to regulate water and electrolyte metabolism. The ability of non-selective MR to bind mineralocorticoids is mediated by 11β-hydroxysteroid 431 Nevic Cell Aggregates in Sentinel Lymph Node Biopsies: Incidence dehydrogenase type II (11βHSD2), which inactivates cortisol to cortisone, preventing in Melanoma vs Non-Melanoma Malignancies and Diagnostic Pitfalls binding of glucocorticoids to MR. In this study, we characterized the expression of MR FA Khokhar, M Garcia-Moliner. Tufts - New England Medical Center, Boston, MA. and 11β-HSD2 in cutaneous adnexal neoplasms (CAN). Background: Sentinel lymph node (SLN) evaluation is a widely used tool for staging Design: We constructed tissue microarrays using paraffin-embedded specimens of patients with melanoma or other malignancies. Nodal nevic cell rests / aggregates from 35 patients with CAN. Expression of MR and 11βHSD2 was investigated by represent a diagnostic pitfall for evaluation of sentinel lymph nodes for malignancy. immunohistochemistry. A recently described mouse MAb MR-18 antibody was used for These nodal inclusions are thought to arise from embryologic entrapment or benign MR; a rabbit polyclonal antibody H-145 was used for 11βHSD2. The cohort of tumors inclusions. consisted of 4 mixed tumors (MT), 3 cylindromas (Cy), 10 poromas, 4 spiradenomas Design: 1235 cases of SLN excisions were collected from the records of the pathology (Sp), 6 clear cell hidradenomas (CCH), 3 syringomas (Sy), 3 porocarcinomas (PoCa), department at Tufts-NEMC (years 1999 – 2007). All SLN biopsies at our institution are and 2 sebaceous carcinomas (SebCa). The level of protein expression was scored routinely evaluated by three H&E levels and by immunohistochemistry as appropiate. semiquantitavely using a scale from 0 to 3+. The cases positive for nevic cell aggregates were examined by immunohistochemistry Results: In normal skin, MR and 11βHSD2 were co- expressed in the secretory cells for S100, Mart1 and, in some cases, HMB-45. of sweat glands and in eccrine ducts, with a predominant nuclear localization for MR Results: Nevic cell aggregates were detected in 12 out of 1235 (1%) cases of SLN and cytoplasmic staining for 11βHSD2. Benign eccrine tumors including MT, Cy, excisions. The incidence was higher for patients with melanoma (11 / 276) at 4% than poroma, Sp, and Sy showed strong expression of MR and 11βHSD2 with accentuation patients who had SLN biopsy for non-melanoma malignancies (1/959) at 0.1%. Nevic of staining in neoplastic ducts. The staining patterns for MR and 11βHSD2 were similar cell rests were almost always identified on the first H&E level. Morphologically, nevic to those seen in normal skin. In contrast, CCH exhibited strong diffuse staining for cells had a benign appearance and were present exclusively within the fibrous capsule both markers. Malignant adnexal tumors including PoCa and SebCa were negative of the ymph node. Immunohistochemical analysis showed them to be Mart1 and S100 for both markers. positive but negative for HMB-45 and Ki-67. One case was positive for both metastatic Expression of MR and 11βHSD2 in cutaneous adnexal tumors melanoma and a nevic cell rest, posing a unique diagnostic challenge. MT Cy Poroma Sp CCH Sy PoCa SebCa Conclusions: The incidence of nevic cell rests was higher in SLN excised for melanoma MR 4/4 3/3 9/10 4/4 6/6 3/3 0/3 0/2 than in SLN biopsies performed for other malignancies. A possible explanation may 11βHSD2 3/4 2/3 7/10 4/4 6/6 3/3 0/3 0/2 be that SLN biopsies for melanoma are stained routinely with S100 and Mart1 at our Conclusions: This is the first characterization of MR and 11βHSD2 in adnexal institution. However, all the nevic cell rests were detected on routine H&E. There was neoplasms. Benign eccrine tumors co-express MR and 11βHSD2, while expression is no age or sex predilection affecting incidence and the nevic cell rests were detected lost in Poca and SebCa. This expression pattern reflects the histogenetic origin of adnexal at various anatomic locations. They represent a major diagnostic pitfall. Considerable tumors and suggests a role of these proteins in tumor progression. Collectively, these difficulty can arise if nevic cell aggregates and metastatic melanoma, are present in data show that MR and 11βHSD2 may be useful markers of eccrine tumors and should the same lymph node. Features of intracapsular location, benign cytology, HMB-45 be included in the IHC panel to more accurately subtype this tumors. and ki-67 negativity help support a diagnosis of benign nevic cell aggregates instead of metastatic disease. 434 Ductal-Type Acrosyringeal Nevus: A Previously Undescribed Table 1 Histologic Variant Melanoma Cases Other malignancies Total CV Lalonde, JS Schulmeier, KM Hiatt, BR Smoller. University of Mississippi Medical No. of sentinel lymph node excisions 276 959 1235 Center, Jackson, MS; University of Arkansas for Medical Sciences, Little Rock, AR. Sentinel lymph nodes with nevic cell rests 11 1 12 Background: Hamartomas of the eccrine apparatus are uncommon; however, various Anatomic Location of SLN with Nevic Cell Rests subtypes have been classified. Those arising from the intraepidermal portion, or Cervical Axillary Inguinal Submandibular Total acrosyringium, are even less common. We could find only two histologic variants of 1 (non-melanoma) 3 6 2 12 acrosyringeal nevus described in the literature. The more common known as eccrine syringofibroadenoma is composed of thin anastomosing epithelial cords and strands 432 C-kit Expression in Acral Lentiginous Melanoma and Nevi: A forming a lattice that is connected to the undersurface of the epidermis. It is histologically Preclinical Study for Gleevec® Therapy in ALM identical to the acrosyringeal nevus of Weedon and Lewis. A second variant, less accepted KM Kitagawa, JM Lee, C Lum, P Bryant-Greenwood. John A. Burns School of as a distinct entity, is the syringoacanthoma. This lesion exhibits prominent acanthosis Medicine, Honolulu, HI. and papillomatosis. We present a novel histologic variant of acrosyringeal nevus. Background: Primary cutaneous melanomas are classified into four major subtypes: Design: An 88 year-old Caucasian female presented with a 2.1 x 1.5 cm, oval-shaped, superficial spreading, lentigo maligna, nodular, and acral lentiginous (ALM). Once smooth, erythematous plaque on her right medial leg. The lesion was asymptomatic and diagnosed, ALM patients often face a poorer prognosis than other subtypes. New of unknown duration. A shave biopsy was performed with clinical suspicion of primary molecular markers are needed to adequately classify all melanoma subtypes, as well skin carcinoma. The specimen was routinely processed and paraffin embedded. as predict their clinical behavior. These molecular alterations may provide novel Results: Hematoxylin and eosin-stained sections showed mild orthohyperkeratosis therapeutic modalities. Pathways for melanoma activation have been extensively studied overlying a thin epidermis with a prominent granular layer and unremarkable spinous including alterations in BRAF and NRAS. ALM however, arises in hypopigmented skin layer. The normal rete peg pattern was not present, and, instead, there was a striking with low levels of sun exposure. Therefore, it has been hypothesized that malignant proliferation of intraepidermal ductules projecting downward from the epidermis into transformation of acral nevi to ALM utilize a different molecular pathway. Curtin et the papillary dermis in place of the retia. The lumina of the ductules were empty. An al found that 36% of ALM had either an increase in c-kit copy number or mutation occasional ductal, rete-like, projection had more than one lumen extending off the main leading to enhanced c-kit expression. stem in an arborizing fashion. The basal cells along the dermo-epidermal junction and Design: A total of 52 ALM cases and 62 acral nevi cases were examined. The cases were extending along the rete-ductules were somewhat palisaded. A rare intraepidermal stained with a rabbit polyclonal anti-CD117/c-kit antibody. Positive cells had identical horn was present. There was occasional anastomosis of these rete-ductules, that ANNUAL MEETING ABSTRACTS 97A was confined to the superficial dermis, unlike the long, thin anastomosing branches of phosphatase of regenerating liver-3 (PRL-3) is involved in the acquisition of metastatic syringofibroadenoma. Only a rare dermal duct component could be identified. The dermis potential. It is overexpressed in metastatic colorectal and gastric carcinomas. In animal exhibited solar elastosis with a somewhat lobular proliferation of capillary lumina in models, it is associated with enhanced mobility, invasive activity, and tumor metastasis of the papillary dermis. Inflammatory cells were scant with only a few lymphocytes and ovarian and melanoma cells. The goal of this study is to investigate PRL-3 expression in rare mast cells, histocytes and plasma cells. human cutaneous melanoma and determine whether PRL-3 can be used as a prognostic Conclusions: We believe this to be a unique hamartomatous lesion of the acrosyringeal or predictive marker. portion of the eccrine sweat gland. Design: 83 human cutaneous melanomas and 9 skin nevi were studied. Paraffin embedded tissue microarrays (TMA) with two 1.0 mm cores of each neoplasm were 435 CRTC1-MAML2 Translocation Is Absent in Primary Mucoepidermoid immunostained with anti-PRL3 monoclonal antibody (5D3.) Two additional TMAs Carcinomas of the Skin with non squamous cell lung (n=25), breast (n=26),endometrial (n=26), colon (n=26), and ovarian (n=25) carcinomas were also immunostained. PRL-3 expression was JK Lennerz, A Perry, JD Pfeifer, AC Lind. Washington University St. Louis, School of correlated with clinicopathologic characteristics including age, Breslow score, Clark’s Medicine, St. Louis, MO. level, TNM staging, lymph node involvement, ulceration, distant metastasis, and local Background: Approximately 60% of mucoepidermoid carcinoms (MEC) of the recurrence. salivary glands are characterized by a t(11;19)(q21-22;p13) translocation, associated Results: PRL-3 expression was examined and was mainly localized to the cytoplasm with significantly lower risk of local recurrence. This oncogenic t(11;19) translocation and membrane. Expression was found in 61 of 83 (73.5%) cutaneous melanomas and 6 results in a fusion gene consisting of exon 1 of CRTC1/MECT1/TORC1 and exons 2- of 9 (66.7%) nevi. PRL-3 was also noted in 88% of non squamous cell lung carcinomas, 5 of MAML2. The resulting fusion protein activates the transcription of the NOTCH 84.6% of breast carcinomas, 76.9% of endometrial carcinomas, 65.4% of colon target gene HES1. While t(11;19) has been shown in salivary gland tumors and clear carcinomas, and 64% of ovarian carcinomas. The mean followup time for melanomas cell hidradenoma of the skin, it remains to be determined if adnexal tumors of the skin was 6.84 years (range 1 month - 17 years) A significant correlation was found between with histomorphological features of MEC harbor the same translocation. a lack of PRL-3 and distant metastasis (P = 0.0318). No significant correlation between Design: The surgical pathology archives of Washington University were searched for PRL-3 expression and other clinicopathologic characteristics was found. cutaneous MEC. Identified cases were reviewed for the presence of the following three Conclusions: Our study shows that the lack of PRL-3 expression in melanoma histopathological features: a) cystic dermal nodule with b) overlying intact epidermis correlates with distant metastasis. PRL-3 is not specific for melanoma, being present and presence of c) three cell types (squamoid, intermediate, mucinous). in non squamous cell lung, breast, endometrial, colon, and ovarian carcinomas. PRL-3 Results: We identified 10 cases with the following population characteristics: mean age expression is not limited to malignant neoplasms, being present in benign nevi. of 55 years (range 9-79 years); 4 men. The sites included: vulva, axilla, sacrum, breast, extremities (n=3), eyelid and forehead. We identified one case with the CRTC1-MAML2 fusion gene by RT-PCR and verified the presence of the t(11;19) by interphase FISH. 438 PRL-3 Protein Expression in Sinonasal and Cutaneous Evaluation of this patient’s medical history revealed a MEC of the minor salivary glands, Melanoma with known metastatic disease. Of the 9 other “primary” cutaneous MEC, none showed MG Lim, JB Arbiser, D Lawson, C Shou, XJ Chang, IM Stein, S Muller, C Cohen. evidence of t(11;19) or the associated fusion gene, and none had a history of MEC at Emory University Hospital, Atlanta, GA; Beijing Institute for Cancer Research, another site. Five of these cases were informative as tested by interphase FISH using Beijing, China; Attogen Biomedical Research, Worchester, MA; Monogenics Ltd., breakapart probe methodology. All 5 showed rearrangement of the CRTC1 gene but Chestnut Hill, MA. no rearrangements of the MAML2 gene. Background: Overexpression of phosphatase of regenerating liver-3 (PRL-3), a protein Conclusions: Adnexal tumors of the skin with histomorphological features of MEC tyrosine phosphatase, is associated with metastasis of colorectal, ovarian, breast, and do not harbor the t(11;19) characteristic of MEC of the salivary gland. However, all gastric carcinomas. Animal models have also shown that overexpression of PRL-3 informative MEC of the skin showed rearrangement of the CRTC1 gene; the fusion in melanoma cells is associated with metastasis. Mucosal melanomas, compared to partner(s) in these cases remains to be determined. cutaneous melanomas, are known to have amplification of PRL-3, to behave more aggressively, and to have a poorer prognosis. Recent studies have identified inhibitors 436 Primary Cutaneous PEComas: Distinctive Clear Cell Lesions of of PRL-3, such as pentamidine and biflavonoids, which may have therapeutic potential. Skin We compared sinonasal mucosal and cutaneous melanomas for PRL-3 overexpression to assess the predictive and possible targeted therapeutic value of PRL-3. B Liegl, JL Hornick, CDM Fletcher. Brigham & Women’s Hospital, Boston. Design: 29 sinonasal melanomas and 83 cutaneous melanomas from all sites were Background: PEComas are defined as mesenchymal tumors composed of histologically immunostained for PRL-3 using monoclonal antibody with overnight incubation at 4 and immunohistochemically distinctive perivascular epithelioid cells. PEComas arising degrees C, but without antigen retrieval. A known PRL-3 positive colon cancer was used in somatic soft tissue or skin are rare. Herein we report 10 primary cutaneous PEComas, as positive control. No stain or <10% staining (0) and faint/barely perceptible staining to further characterize the clinicopathologic spectrum. (1+) were regarded as negative; moderate or strong complete staining (2+, 3+) in 10% Design: Cutaneous PEComas and unclassified clear or granular cell cutaneous neoplasms of tumor cells were regarded as positive. received between 1989 and 2007 were evaluated. All cases were re-examined to evaluate: Results: 26 of 29 (89.7%) sinonasal melanomas expressed cytoplasmic and membranous tumor margins, architectural pattern (nested, circumscribed, infiltrative), cell types PRL-3; 23 (85%) of positive melanoma had 3+ staining intensity with expression present (epithelioid, spindled), cytoplasm (clear, palely eosinophilic, or granular), cytologic in >50% of cells. Of the cutaneous melanomas, 61 of 83 (73.5%) expressed PRL-3; 46 atypia, mitotic rate and necrosis. Immunohistochemical stains for SMA, Desmin, (75.4%) of these positively staining melanomas had 3+ staining intensity, present in Caldesmon, Calponin, HMB-45, Melan A, MiTF, S-100, EMA and Pan-Keratin were > 50% of tumor cells. The frequencies of strong staining for PRL-3 in sinonasal and performed. cutaneous melanomas were not significantly different (p= >0.05). Results: Eight patients were female; 2 were male. The age ranged from 15-81 yrs Conclusions: PRL-3 overexpression is noted in the majority of sinonasal and cutaneous (median 52 yrs). None had tuberous sclerosis. Tumor size ranged from 0.7 to 2 cm melanomas, usually strong and diffuse in distribution. It does not appear to be a marker (median 1.5 cm). Eight tumors were located on the limbs and 2 on the back. The of metastatic or more aggressive behavior for melanomas of any particular site. Targeted tumors involved the dermis and were generally well circumscribed, but peripheral therapy against PRL-3 may be useful in melanoma in general, but not specifically for entrapment of dermal collagen and infiltration into subcutaneous fat was often present. those of sinonasal origin. Architecturally, a nested or focally trabecular growth pattern with associated delicate thin-walled capillaries was observed. Six tumors were composed of epithelioid cells and 4 showed mixed epithelioid and spindle cell morphology. Tumor cells had clear, 439 Spindle Cell Carcinoma of the Skin: A Clinicopathological palely eosinophilic or granular cytoplasm. Multinucleate tumor giant cells were Analysis of 30 Cases observed in 3 cases. Mitotic activity ranged from 0 to 2 mitoses per 30 high power B Luzar, W-L Wang, R Asher, AJ Lazar, M Bracko, E Calonje. Medical Faculty, Ljubljana, fields. Pleomorphism or necrosis was absent. All cases showed at least focal positivity Slovenia; UT-MD Anderson Cancer Center, Houston, TX; St John’s Institute of for HMB-45. Melan A was positive in 5/7. In cases where HMB-45 was positive in Dermatology, London, United Kingdom; Institute of Oncology, Ljubljana, Slovenia. fewer than 5% of tumor cells (5/10), MiTF was positive in the majority of the tumor Background: To analyse various clinico-pathological parameters and to correlate them cell nuclei. Desmin positivity was observed in 5 and SMA in 1 case. The other muscle with survival of patients with spindle cell carcinoma of the skin. markers (caldesmon, calponin) as well as Pan-Keratin and EMA were negative. Follow Design: Parameters studied in 30 patients were: gender, age, location, tumour size, up data were available in 6 cases and ranged between 3 and 108 months (median 47 connection to epidermis, depth of invasion, perineural, blood vessel and lymphatic months). No lesion has recurred to date. invasion, tumoral necrosis, other type of squamous differentiation, previous irradiation, Conclusions: Primary cutaneous PEComas are rare apparently benign cutaneous tumors local recurrence, and presence of metastatic disease. By immunohistochemisty, we which predominantly affect adult females. The main differential diagnoses include evaluated wide spectrum cytokeratin, cytokeratin MNF116, cytokeratin AE1/AE3, EMA, balloon cell melanocytic lesions, so-called distinctive dermal clear cell neoplasm, S100, smooth muscle actin and desmin. Follow-up data was obtained form patients’ metastatic renal cell carcinoma and clear cell benign fibrous histiocytoma. Accurate charts and Cancer Registries. recognition of this entity is essential to avoid misdiagnosis as malignant tumors, Results: Follow-up, available for 23 patients, was from 2 - 230 months (mean 41): especially malignant melanoma. 10 were alive and without disease, 9 died of unrelated causes, 3 died of disease and one was alive with metastatic disease. 10 cases had moderate/poorly differentiated 437 PRL-3 Expression – Possible Prognostic and Predictive Marker squamous cell carcinoma in the vicinity of spindle cell component. Blood vessel in Primary Cutaneous Melanoma invasion was found in 4, invasion of lymphatics in 4 and perineural invasion in 8 patients. Five patients had loco-regional lymph-node metastases and 3 had systemic MG Lim, D Lawson, G Cotsonis, XJ Chang, C Shou, IM Stein, C Cohen. Emory metastases. Multivariate analysis revealed blood vessel invasion as the only independent University Hospital, Atlanta, GA; Attogen Biomedical Research, Worcester, MA; Beijing prognostic factor associated with poor outcome (p=0.01). By univariate analysis, local Institute for Cancer Research, Beijing, China; Monogenics Ltd., Chestnut Hill, MA. recurrence correlated with depth of invasion (p=0.02), lymphatic invasion (p=0.018) Background: Protein tyrosine phosphatases play an important role in the regulation and development of metastases (p=0.006). Perineural invasion was related to depth of of cellular physiologic and pathologic processes. Recent studies have shown that 98A ANNUAL MEETING ABSTRACTS invasion (p=0.003), while development of metastases correlated with depth of invasion Tucson, AZ) cytoplasmic expression was determined with adequate positive and negative (p=0.02), vascular invasion (p=0.001), lymphatic invasion (p=0.001) and tumoral controls. The results were graded as weak, moderate or strong based on the intensity of necrosis (p=0.002). stained cells constituting the neoplasm. Conclusions: Spindle cell carcinoma of the skin is a disease of elderly, occurring most Results: Fifteen of the sixteen tumors that were studied possessed strong diffuse frequently in the seventh decade on sun-exposed skin. On presentation, tumour usually cytoplasmic reactivity. CD117 staining was seen in perinuclear/cytoplasmic location measures less that 20 mm, but infiltrates subcutis. Local recurrence is directly related of cells comprising an average thirty percent of the tumor. While fifteen of the sixteen to non-radical excision. Blood vessel invasion is the only independent histological cases studied had strong staining, the staining pattern was only seen among the spindle parameter associated with poor outcome. A combination of cytokeratins is advisable cells constituting the neoplasm. Interestingly, the majority of anaplastic, multinucleated for immunohistochemical confirmation of squamous differentiation since staining for cells did not stain. The epithelium with the exception of melanocytes, dermal structures single cytokeratin may be inconsistent: absent, focal or diffuse. including adnexa did not stain. Rare tumor associated mast cells showed staining for CD117. 440 Cutaneous Leiomyosarcoma: Clinico-Pathologic Analysis of 76 Conclusions: We have demonstrated that CD117 staining is present in AFX. CD117 Cases immunoreactivity would appear to be sensitive for AFX. We hope this study will lead others to investigate its potential diagnostic utility and ultimately, its pathogenic D Massi, A Franchi, L Alos, M Cook, S Di Palma, B Enguita, G Ferrara, D Kazakov, relationship to AFX. T Mentzel, M Michal, I Panelos, JR Peralto, M Santucci, G Tragni, A Zioga, AP Dei Tos. University of Florence, Florence, Japan; Hospital Clinic, Barcelona, Spain; Royal Surrey County Hospital, Guilford, United Kingdom; Hospital Universitario 2 de 443 Can Histology of Recurrence Distinguish Banal from Dysplastic Octubre, Madrid, Spain; Gaetano Rummo Hospital, Benevento, Italy; Charles University Nevi? Medical Faculty Hospital, Pilsen, Czech Republic; Geneinschftpraxis, Friedrichshafen, EC Miller, SR Tahan. Beth Israel Deaconess Medical Center, Boston, MA; Harvard Germany; University of Ioannina, Ioannina, Greece; Istituto Nazionale Tumori, Milan, Medical School, Boston, MA. Italy; Regional Hospital of Treviso, Treviso, Italy. Background: Features of recurrence after incomplete removal of melanocytic nevi have Background: Cutaneous leiomyosarcoma (LMS) is an uncommon entity. Tumors been described (“recurrent nevus phenomenon”), however no studies have addressed confined to the dermis have been reported to carry a favorable prognosis whereas whether there are any differences in the histology of recurrent banal versus dysplastic subcutaneous LMS showing mitotic activity and cytological atypia can metastasize. nevi. The aim of this study is to determine if histologic features present in a local Design: 76 cases were retrieved from the surgical pathology and consultation recurrence can distinguish regrowth of a banal nevus from a dysplastic nevus. Authors’ files. Hematoxylin-and-eosin stained slides were reviewed, diagnoses were Design: All 25 skin excisions identified as containing locally “recurrent nevus” from the confirmed and all tumors were stained for smooth muscle actin (SMA), desmin and 1995-2007 BIDMC archives with available slides of the original biopsy and recurrence h-caldesmon. were entered into this study. The original biopsies were reviewed: 10 lesions were Results: 61 patients were male and 15 were female (median age 71 years, range 22 to classified as banal and 15 as dysplastic nevi using established criteria. Slides from 98 years of age). Tumor size ranged from 0.4 to 6 cm. The most frequent sites were the recurrence were then reviewed by two observers blinded to the pathology of the extremities (26), head and neck (24), followed by trunk and genitals. Past medical original lesion for the following parameters: patient age, gender, location (head/neck, history showed radiotherapy in 4 cases; one immunosuppressed patient had a previous trunk, extremity), weeks to re-excision, margins (positive vs negative), single cell vs renal transplantation. Completely excised tumors were: purely dermal (17), dermal nested pattern, Pagetoid spread (none, low, high), upward spread of pigmentation (none, with minimal extension to the subcutis (17), dermal and subcutaneous (35), purely low, high), bridging (present/absent), nesting (present/absent), adnexal involvement subcutaneous (2). Clinical follow-up in 55 cases, ranging from 1-288 months (median (present/absent), recurrence within scar, predominant cell type (spindle vs epithelioid), follow up 36 months), revealed local, often late, recurrences in 15 cases (27.7%) and intraepidermal nuclear atypia (none, low grade, high grade), intraepidermal nuclear evidence of distant metastases in 4 cases (7.4%). Interestingly, one case of dermal LMS and cell size (small, large, very large), intraepidermal mitosis (present vs absent), with minimal extension to the subcutis developed distant visceral metastases 15 years dermal nuclear atypia (none, low grade, high grade), dermal mitosis (present/absent), after the initial diagnosis. melanophages (none, few, many), and lymphocytic response (present/absent). Fisher’s Conclusions: Cutaneous LMS shows peculiar architectural features, distinctive from exact test was used to compare category data and the unpaired t-test for variables its soft tissue counterpart. Lesions involving the subcutis have a higher recurrent and between groups. metastatic potential in comparison with dermal LMS. However, although rarely, also Results: In this cohort, re-excisions of recurrences were performed from 6 to 155 weeks dermal LMS may metastatize and therefore long-term follow up is mandatory. after biopsy. Only regrowth within scar (7 of 10 banal nevi versus 4 of 15 dysplastic nevi, P=0.05) among the 20 analyzed parameters differed between banal and dysplastic 441 PAR-2 Is Downregulated in Keratinocytes from Lesions nevi. Interval to re-excision did not affect any parameter. Of interest, intraepidermal mitoses were only encountered within lesions re-excised within 10 weeks of biopsy, D Massi, R Nassini, S Materazzi, A Naldini, F Prignano, A Pacini, F Tarantini, S Moretti. with a trend for the dysplastic group. University of Florence, Florence, Italy; University of Siena, Siena, Italy. Conclusions: No histologic parameter of recurrence beside regrowth within scar Background: Protease-activated receptor-2 (PAR-2) belongs to a G protein-coupled differentiated banal from dysplastic nevi in this pilot study. This implies that one cannot receptor superfamily, activated by the proteolytic cleavage of their extracellular amino reliably judge the nature of the original nevus based on evaluation of the histology of terminal domain. PAR-2 is expressed by epidermal keratinocytes, where its activation by the recurrence. trypsin-like enzymes affects epidermal pigmentation through modulation of melanosome uptake. Vitiligo is a skin disorder characterized by melanocyte impairment and loss of in keratinocytes. Thus, we hypothesized that PAR-2 dysregulation could be 444 Whole Slide Dematopathology Image Repository: A Valuable involved in the mechanism of vitiligo. Resource for Pathology Residency Training and Practice Design: Immunohistochemical staining for PAR-2 protein was evaluated in skin SK Mohanty, M Keady, J Bhawan, M Mahalingam. University of Massachusetts Medical specimens taken from 23 vitiligo patients with active disease. PAR-2 mRNA levels Center, Worcester, MA; Boston University Medical School, Boston, MA. were evaluated by Ribonuclease Protection Assay (RPA) in 15 selected samples. Background: Whole Slide Imaging (WSI) automatically images the entire slide at Expression (mRNA) and function (mobilization of intracellular Ca2+, [Ca2+]i) of PAR- high speed and produces high-resolution facsimiles, and is a valuable resource as an 2 was studied in primary cultures of keratinocytes from lesional and healthy skin of educational tool. The principal objectives of this project were to assess the feasibility vitiligo patients. of creating a high-quality and comprehensive annotation of a spectrum of cases in Results: PAR-2 mRNA and protein expression was markedly reduced in keratinocytes dermatopathology with a view to creating a library of utility as a teaching tool for from lesional versus perilesional and normal epidermis. Cultured keratinocytes from residents. depigmented lesions exhibited lower PAR-2 mRNA levels as compared to healthy skin. Design: Automated whole slide image capture was performed using a microscope 2+ The PAR-2 agonists, SLIGKV-NH2 and trypsin, produced a reduced [Ca ]i response with the aid of Coolscope’s motorized stage, video camera and webSlide VS software in keratinocytes from lesional skin as compared to healthy skin. (Bacus Labs, IL). The camera runs at 1.3 mega pixels with a resolution of 1280 x 960. Conclusions: PAR-2 expression is selectively reduced in keratinocytes from skin areas The system ran in automated batch mode with automated focus. Mouse point-and- of vitiligo characterized by pigment loss. The reduction observed in vivo appears to be click operations performed on the Slide View image generated moved the slide under associated with a reduced PAR-2 function in vitro. These data support a primary role the Coolscope’s high magnification objectives. 20x WSI images of specific areas of of PAR-2 in the mechanism of depigmentation in vitiligo. interest were captured. Results: After automated image capture, the imaging technician visually examined 442 CD117 Immunoreactivity in Atypical Fibroxanthoma whole slide images for image quality. A test run indicated that the time for scanning one slide at 20X magnification was observed to vary anywhere from 60-180 minutes RA Mathew, SM Schlauder, K Calder, MB Morgan. University of South Florida, depending on the section size. The quality of the image was found to be optimal. Images Tampa, FL. were compressed during the capture process in a multi-layered JPG2000 format. Background: Atypical fibroxanthoma (AFX) is a spindle cell neoplasm of the skin seen Conclusions: Over the past five years WSI technology is becoming ubiquitous in typically on sun-damaged skin of the elderly. Though described as a benign entity, local educational settings. Our preliminary pilot study indicates that acquiring a fully recurrence and distant metastasis have been reported. This study aims to investigate the annotated and comprehensive collection of teaching material is a feasible but a time potential pathogenic role of CD117, the c-kit receptor in AFX. consuming goal. Design: A diagnostic coded search of the database at James A Haley VA in Tampa FL was performed for all cases of AFX between years 2004 to 2007. Sixteen cases were found and the diagnosis was confirmed by a single board certified dermatopathologist (MBM). These diagnoses were rendered on the basis of published morphologic criteria and with the aid of immunohistochemical markers typically CD68(+), S100(-), smooth muscle actin(-), cytokeratin-903(-), and pankeratin(-). CD117 (prediluted Ventana, ANNUAL MEETING ABSTRACTS 99A

445 Quantitative Assessment of Dermal Fibroblasts in Nephrogenic 447 Cutaneous Lymphomas with Prominent Granulomatous Systemic Fibrosis Component: Clinicopathological Features in a Series of 16 Cases RM Nazarian, RV Mandal, A Kagan, J Kay, LM Duncan. Massachusetts General A Padron, C Barranco, F Gallardo, R Esgueva, P Blanco, A Ariza, R Pujol, S Serrano. Hospital, Boston, MA. IMAS, UAB, Hospital del Mar, Barcelona, Spain; Hospital Germans Trias i Pujol, Background: Nephrogenic systemic fibrosis (NSF) is a recently described disorder UAB, Badalaona, Barcelona, Spain. affecting patients with impaired renal function who previously received gadolinium- Background: The presence of a prominent granulomatous tissue reaction in skin containing radiographic contrast. Commonly reported histopathologic findings biopsies from primary or secondary cutaneous malignant lymphomas is a rare but on cutaneous biopsies from patients diagnosed with NSF include: fibroblast cell well-known phenomenon. proliferation, increased mucin deposition, and thickened collagen bundles with adjacent Design: Sixteen patients (8 males and 8 females) with cutaneous malignant lymphoma clefts within the dermis. The current study aims to confirm whether the dermal fibroblast showing a prominent granulomatous inflammatory infiltrate were retrieved from cell count in skin biopsies from patients diagnosed with NSF differs significantly from the Catalan Cutaneous Lymphoma Network database (in which 987 patients are that of non-NSF patients and whether there is any correlation with age of the skin registered). Of the 16 patients, mycosis fungoides was present in 5 cases (2 of them lesion, level of plasma creatinine, and symptom-preceding dose or cumulative dose with granulomatous slack skin [GSS] features), Sézary syndrome in 1 case, CD30+ of gadolinium. large cutaneous T-cell lymphoma (CTCL) in 2 cases, CD4+ peripheral CTCL in 1 case, Design: Five high-power fields (hpf) from 5mm &H E stained formalin-fixed paraffin- and primary cutaneous B-cell lymphoma in 3 cases. The remaining 4 patients showed embedded skin biopsy sections were digitally photographed from 17 histologically peripheral T-cell lymphoma with secondary epithelioid granulomatous involvement of confirmed cases of NSF and 17 non-NSF controls. The total number of dermal fibroblast the skin. Clinical presentation and course, histologic appearance, and immunophenotype nuclei was then manually quantified by three independent observers. Demographic were reviewed. and clinical data were reviewed to determine plasma creatinine, gadolinium dose Results: Clinically, lesions were patches (n=1), papules (n=1), plaques (n=6), or nodules administered, and duration from time of last gadolinium exposure for all patients. (n=8). Except for the 2 cases showing GSS, clinical findings did not allow to suspect Results: The dermal fibroblast cell count was significantly greater for all NSF cases the presence of underlying granulomatous reactions. Histologically, non-necrotizing (mean: 68.87/hpf) in comparison to negative controls (mean: 14.03/hpf). There was high (sarcoid-like) granuloma formation was the most common (11 cases) granulomatous inter-observer agreement for cases and controls with Pearson correlation coefficients of pattern identified. Additionally, GSS was observed in 2 cases, granuloma annulare-like 0.945 (p<0.01) and 0.726 (p<0.01), respectively. Controls were matched for age (mean: findings in 4 cases (of these, sarcoid-like granulomas were also present in one case and 63, range: 36-79 years), sex (11 male, 6 female), and site (forearm, thigh, and lower leg necrotizing tuberculoid granulomas in another). Of note, no definite diagnostic features skin biopsies). No significant correlation between dermal fibroblast cell count and time of lymphoma were initially present in 5 (31%) cases. No significant differences regarding from last gadolinium exposure, symptom-preceding dose or cumulative gadolinium prognosis could be demonstrated. dose, and plasma creatinine at time of skin biopsy was identified. Conclusions: The diagnosis of granulomatous variants of cutaneous lymphoma is based Conclusions: To our knowledge, this is the first study to quantitatively assess the extent on the presence of a malignant lymphoid infitrates in conjunction with a prominent of dermal fibroblast proliferation in NSF. Our results substantiate previous reports of granulomatous . However, the features of the granulomatous component increased dermal fibroblast number as a diagnostic histologic feature in skin biopsies of are quite inconstant, even among different biopsies from a given patient. Diagnosis, patients with NSF with high interobserver correlation. The extent of dermal fibroblast therefore, relies on clinical presentation and the features of the non-granulomatous proliferation does not correlate with increased age of skin lesion, dose of gadolinium component, with demonstration of a monoclonal lymphoid population. Occurrence of administered, or plasma creatinine at the time of skin biopsy. granulomatous inflammation in cutaneous lymphoma does not seem to have prognostic implications. 446 Intra- and Peri-Tumoral Lymphocytic Response Is Associated with Loss of DNA Mismatch Repair (MMR) Protein in Sebaceous Neoplasms 448 Loss of BRMS1 Expression Is Strongly Associated with (SNs) Metastatic Potential of Malignant Melanoma L Orta, D Klimstra, P Mecca, L Tang, K Busam, J Shia. Memorial Sloan-Kettering PA Phadke, H Ashby-Richardson, A Shepard-Barry, SP Naber, DR Welch. New England Cancer Center, NY. Medical Center, Boston, MA; University of Alabama at Birmingham, Birmingham, Background: Development of SNs and visceral malignancies is characteristic of AL. Muir-Torre syndrome, a variant of hereditary nonpolyposis colorectal cancer (HNPCC) Background: Breast Cancer Metastasis Suppressor 1 (BRMS1) is a recently discovered syndrome. The fundamental genetic defect lies in DNA MMR genes. Colorectal and metastasis suppressor gene. So far, most human and animal studies have focused on endometrial tumors in HNPCC are shown to have a specific phenotype: increased tumor breast cancer and demonstrated that BRMS1 suppresses multiple organ metastasis by infiltrating lymphocytes (TILs) with or without peri-tumoral lymphoid response (PTLR), affecting numerous steps of the metastatic cascade, without affecting primary tumor a feature that carries both predictive value in detecting MMR deficiency and potential growth. The role of BRMS1 in primary and metastatic melanoma has not been tested in implication in prognosis and therapy. The purpose of this study was to assess whether detail. BRMS1 was shown, in a single study, to significantly suppress lung metastasis these histologic features were present in SNs deficient in DNA MMR. in nude mice using human melanoma cell lines. The current study is the first using Design: Immunohistochemical (IHC) staining for CD3 was performed in 17 extra-ocular human tissue and explores BRMS1 expression patterns in various melanocytic lesions sebaceous carcinomas (SC) and 11 sebaceous adenomas (SA) from 16 and 6 patients, to determine its role in human melanoma progression and metastasis. respectively. MMR protein status by IHC staining was known from a previous study: Design: 14 cases of benign intradermal nevi, 33 cases of malignant melanoma, and 8/17 SCs and 9/11 SAs were deficient in at least 1 of 4 proteins (MLH1, MSH2, MSH6 53 cases of metastatic melanoma (25 lymph node, 10 brain, 5 lung, 7 skin and soft and PMS2). The number of CD3-positive TILs/5 high power fields (HPFs) and PTLR tissue, 2 parotid gland, 1 bone, 1 appendix, 1 omentum and 1 spleen) were studied. (graded 0, 1+, 2+ or 3+) were correlated with the MMR IHC results. Immunohistochemical staining for BRMS1 was performed using a custom made Results: CD3-positive TIL counts are summarized in Table 1. monoclonal antibody (Clone 3a1.21) on paraffin-embedded formalin-fixed tissue. Table 1. TIL counts in different patient groups* Expression was graded based on intensity (0-3) and percentage of cells staining for CD3-positive TIL/5 HPFs BRMS1. Range Median Mean P value Results: BRMS1 was expressed strongly in 14/14 benign nevi. Staining was SC (n=17) MMR normal by IHC (n=9) 0-14.6 0.8 3.0 0.004 predominantly nuclear, with a diffuse and intense staining pattern. The primary MMR abnormal by IHC (n=8) 3.2-39.4 11.7 16.0 SA (n=11) MMR normal by IHC (n=2) 0.2, 0.4 0.3 0.3 0.007 melanomas showed a significant decrease in BRMS1 expression compared to benign MMR abnormal by IHC (n=9) 0.2-25 7.6 8.2 nevi (P<0.001). A further reduction in BRMS1 protein levels was observed in metastatic *No significant difference between SCs and SAs (p=0.56). melanoma compared to both benign nevi and primary melanomas (P<0.001). A slight Using 5/5 HPFs and 2+ as cutoffs for TIL and PTLR, respectively, the value of these 2 increase in cytoplasmic staining of BRMS1 was noted in the primary and metastatic features in predicting MMR protein status is summarized in Table 2. melanoma groups. Table 2. Sensitivity and specificity of lymphocytic response in predicting abnormal MMR protein Conclusions: The dramatic reduction of BRMS1 expression in primary and metastatic by IHC. melanoma as compared to benign nevi suggests an important role for the BRMS1 protein IHC for MMR proteins Sensitivity Specificity in the regulation of melanoma progression and metastasis. Secondly, the greater loss Normal Abnormal of expression in metastases compared to primary melanoma suggests that BRMS1 is SC (n=17) TIL*>=5 1 6 75% (6/8) 89% (8/9) critical in the later stages of melanoma progression and correlates well with its role as a TIL*<5 8 2 metastasis suppressor gene. Whether the increase in cytoplasmic BRMS1 is functionally PTLR>=2+ 2 6 75% (6/8) 78% (7/9) relevant needs further evaluation. Currently, studies using survival data are underway PTLR<2+ 7 2 to address the prognostic and potential therapeutic utility of BRMS1 in advanced and SA (n=11) metastatic melanoma. TIL*>=5 0 6 67% (6/9) 2/2 TIL*<5 2 3 PTLR>=2+ 0 6 67% (6/9) 2/2 449 HER-2/Neu Expression in Extramammary Paget Disease: A PTLR<2+ 2 3 Clinicopathologic and Immunohistochemistry Study of 47 Cases with and * CD3-positive TILs in 5 HPFs. without Underlying Malignancies Conclusions: Intra- and peri-tumoral lymphocytic response is heightened in SNs that JA Plaza, C Torres-Cabala, D Ivan, VG Prieto. M.D. Anderson Cancer Center, show abnormal MMR protein expression, suggesting a similar relationship between Houston, TX. tumor phenotype and MMR abnormality in SNs as in colorectal or endometrial tumors. Background: Extramammary Paget disease (EMPD) is an infrequent and distinct form Awareness of such histologic features will help increase identification of individuals at skin cancer of unknown histogenesis, rarely representing a secondary event caused by risk for deficiency in the MMR genes. extension of a primary adenocarcinoma. Her-2/Neu overexpression in breast cancer is correlated with a more aggressive behavior; the newly introduced anti-Her-2/Neu antibody has been proven to improve survival in these patients. We investigated Her- 100A ANNUAL MEETING ABSTRACTS

2/Neu expression by immunohistochemistry in EMPD with and without underlying Conclusions: 1. KOC is expressed in Merkel cell carcinomas with an expression pattern malignancy to try to correlate with tumor recurrence, progression, and possible similar to pulmonary and extrapulmonary small cell carcinomas. 2. KOC may play an targeted therapy. important role in the regulation of the biological behavior of high-grade neuroendocrine Design: 47 cases of EMPD were retrieved. Clinical data information were obtained from carcinomas, including Merkel cell carcinomas. the hospital records. Immunohistochemical studies against Her-2/Neu were performed in all cases using formalin-fixed, paraffin-embedded tissue sections. Following the 452 Immunohistochemical Distinction of Cutaneous Spindle Cell U.S. FDA-approved scoring guidelines for breast carcinomas, only membrane staining Carcinoma was assessed using the 0 to 3+ scale illustrated in the HercepTest scoring guideline. C Purohit, T Anglin, M Morgan. University of South Florida, Tampa, FL. Overexpression was considered as positive for scores 2 and 3+. Background: Cutaneous spindle cell carcinoma is an uncommon variant of squamous Results: Of the 47 lesions, 6 were from the scrotum, 7 perineum, 1 axilla, and 33 vulva. cell carcinoma in which keratinocytes infiltrate the dermis as single cells with elongated Only 2 cases had invasive EMPD (1 case from vulva and 1 from scrotum). Overall the nuclei rather than cohesive nests or islands, and signs of keratinization of conventional expression among all cases of EMPD in this study was 31.9%. Of the non-invasive SCC are insubstantial. Spindle cell carcinoma must be distinguished from spindle EMPD of the vulva (32 cases) Her-2/Neu was demonstrated in 13 cases (38%), 4 cases cell/desmoplastic melanoma, cutaneous leiomyosarcoma, atypical fibroxanthoma and were 3+ and 9 cases were 2+. The invasive vulvar EMPD was negative. All scrotal scar. In instances when there is no definitive evidence of sqamous differentiation, IHC EMPD (6 cases) lack Her-2/Neu expression (including the invasive one). Of the 7 studies may confer diagnostic discrimination. EMPD, Her-2/Neu was expressed in 2 cases (33.3%); they were scored as 3+. The Design: 24 cases consisting of 12 spindle cell SCC, 3 atypical fibroxanthoma, 3 EMPD on the axilla (1 case) was negative. 3 of the cases that had vulvar EMPD also leiomyosarcoma, 3 desmoplastic melanomas and 3 scars were immunostained with a had history of invasive ductal (2 cases) and lobular (1 case) carcinoma of the breast; battery of immunohistochemical stains with specificity and sensitivity of each marker all of these cases were negative for Her-2/Neu in both the primary breast and EMPD calculated. The IHC battery consisted of S-100, desmin, CD68, and SMA as well as tumor. 18 cases had recurrence and of these 44.4% showed Her-2/Neu expression in cytokeratins HMWK, LMWK, Pan-K and CK903. the initial lesion. Results: SCCs stained negative for S-100, CD68, SMA and desmin with the exception of Conclusions: A high proportion of EMPD (31.9%) shows Her-2/Neu expression two cases with weak staining for SMA. CK903 provided positive results for each SCC. indicating that these patients may benefit from targeted therapy. The proportion of The other cytokeratin stains conferred less sensitivity for SCC than CK903. The final IHC positive cases was higher in lesions that had recurred at last follow-up (44.4%), thus results were as follows: CK903 (12/12, 100%), Pan-K (8/12, 67%), LMWK (7/12, 58%), suggesting a more aggressive behavior. and HMWK (4/12, 33%). The 3 atypical fibroxanthomas stained positive for CD68 and negative for all other stains while the 3 leiomyosarcomas stained positively for desmin 450 Diagnostic Value of CD163 in Cutaneous Spindle Cell Lesions and SMA and negatively for all other stains. The 3 melanomas stained positively for P Pouryazdanparast, L Yu, J Cutlan, D Fullen, L Ma. University of Michigan, Ann S-100 and negatively for all other IHC. The scars stained negatively for all stains. Arbor, MI. Conclusions: IHC staining constitutes an important diagnostic adjunct in the Background: In pathology practice, a specific marker is lacking for atypical armamentarium of the dermatopathologist. This utility is exemplified in the discernment fibroxanthoma (AFX). Recently, CD163 (a hemoglobin scavenger receptor) was shown of spindled dermal neoplasms. In conclusion, CK903 proved most promising in to have greater tissue specificity for tumors derived from the monocyte/histiocyte lineage, identifying spindle cell squamous cell carcinoma with a sensitivity and specificity when comparing it with other conventional histiocytic markers (i.e. CD68). Although of 100%. the expression of CD163 was detected in one of three AFX cases, its utilization in the differential diagnosis of cutaneous spindle cell tumors has not been systemically 453 Diagnostic Utility of Mash1 in Differentiating Small Cell Carcinoma assessed. In this study, we evaluated the diagnostic utility of CD163 in separating of the Lung from Merkel Cell Carcinoma AFX from other cutaneous spindle cell lesions and in identifying cutaneous lesions JS Ralston, D Nonaka, L Chiriboga. New York University, New York, NY. with histiocytic derivation. Background: Achaete-scute complex-like 1 (Mash1, hASH1, ASCL1) is a basic Design: Using tissue microarrays, CD163 immunohistochemical stains were performed helix-loop-helix transcription factor crucial for pulmonary neuroendocrine cell (PNEC) on 102 cutaneous spindle cell and some histiocytic lesions, including 10 AFX, 5 spindle differentiation. Mash1 has been reported to be expressed in some human neuroendocrine cell variant squamous cell carcinomas (SCC), 7 spindle cell melanomas (SCM), neoplasms, including small cell carcinoma and large cell neuroendocrine carcinoma 26 benign fibrous histiocytomas (DF, various variants), 10 dermatofibrosarcoma of the lung, neuroblastoma, pheochromocytoma, thyroid medullary carcinoma, and protuberans (DFSP), 5 dermatomyofibromas, 10 neurofibromas (NF), 8 leiomyomas, 4 primitive neuroectodermal tumors. Only a few reports have evaluated Mash1 expression leiomyosarcomas, 6 juvenile xanthogranulomas (JXG), 4 xanthomas, 3 Langerhans cell in Merkel cell carcinoma, and have only shown minimal expression in real-time PCR histiocytosis (LCH), 2 reticulohistocytomas, and 2 Rosai-Dorfman disease. Additionally, analysis. No studies have evaluated the diagnostic utility of Mash1 immunostaining in 9 malignant fibrous histiocytomas (MFH) were stained. The amount of staining was differentiating between small cell carcinoma of the lung and Merkel cell carcinoma. semiquantitatively recorded as negative (<10%), <20%, 20-50%, >50%. Design: A total of 26 cases of Merkel cell carcinoma and 24 cases of small cell carcinoma Results: In normal skin, CD163 labeled the dermal dendritic cells. Positive CD163 of the lung were studied. Immunostains for Mash1 and TTF-1 were performed using immunoreactivity was seen in 8/10 (80%) AFX, 3/7 (43%) SCM, 22/26 (85%) DF, 1/5 tissue microarrays and conventional whole sections. The extent of staining was graded (20%) dermatomyofibromas, and 6/9 (67%) MFH. Among positive cases, 5/8 AFX as 1+, 1-25%; 2+, 25-50%; 3+, 50-75%; 4+, >75%. demonstrated diffuse staining, while 1/3 SCM had diffuse reactivity. All cellular DF Results: Both Mash1 and TTF-1 were completely negative in all Merkel cell carcinomas. and epithelioid cell histiocytoma displayed strong labeling. Intense and diffuse CD163 Mash1 expression was observed in 91.3% of small cell carcinomas generally with strong staining was also observed in all cases of xanthoma, JXG, reticulohistiocytoma, LCH, intensity, and 56.5% of the cases showed diffuse (3+/4+) reaction. TTF-1 expression and Rosai-Dorfman disease. In comparison, none of the SCC, DFSP, NF, leiomyoma, was observed in 88.2% of small cell carcinomas mostly with strong intensity, and and leiomyosarcoma showed CD163 expression. 78.3% demonstrated diffuse reaction. There were two cases of TTF-1 negative/Mash1 Conclusions: 1. CD163 is a useful marker in distinguishing AFX from other cutaneous positive small cell carcinomas. spindle cell tumors, such as SCC, DFSP and leiomyosarcoma. However, special caution Conclusions: Mash1 is a useful adjunct marker for the diagnosis of small cell carcinoma should be taken when using CD163 to differentiate AFX from SCM, since some of the lung, particularly when the differential diagnosis includes Merkel cell carcinoma. cases of SCM may show focal positivity. 2. CD 163 is a relatively specific marker While TTF-1 in conjunction with cytokeratins 7 and 20 will differentiate most Merkel for identifying cutaneous histocyte/dendrocyte-derived lesions, such as DF, JXG, and cell carcinomas from small cell carcinomas, Mash1 offers another useful marker. These reticulohistiocytoma. 3. CD163 is helpful in separating DF from DFSP. findings correlate with those of the previous real-time PCR study. Additionally, as Mash1 has been shown to have a role in PNEC differentiation and has been previously 451 Merkel Cell Carcinomas Express K Homology Domain Containing shown to be particularly expressed in small cell carcinomas of the lung, it may be a Protein Overexpressed in Cancer like Small Cell Carcinomas useful target for future therapies. JG Pryor, RA Simon, PA Bourne, BO Spaulding, GA Scott, H Xu. University of Rochester Medical Center, Rochester, NY; Dako North America, Carpinteria, CA. 454 Diagnostic Utility of Immunohistochemical Stains To Differentiate Background: K homology domain containing protein overexpressed in cancer (KOC) is Metastatic Breast Carcinoma to Skin from Primary Sweat Gland a member of the insulin-like growth factor (IGF) mRNA-binding protein (IMP) family Carcinomas and is expressed during embryonic development and in some malignancies. KOC, also MA Rollins-Raval, M Chivukula, D Jukic, DJ Dabbs. University of Pittsburgh Medical known as L523S and IMP3, promotes tumor cell proliferation by enhancing IGF-II Center, Pittsburgh, PA. protein expression. We previously reported that KOC is expressed in pulmonary and Background: Cutaneous metastasis of breast cancer (CMBC) has an incidence of ∼25% extrapulmonary small cell carcinomas, but not in carcinoid tumors. KOC expression in clinical practice. Primary sweat gland carcinomas (PSGC) account for ∼0.005% of all in neuroendocrine carcinomas of the skin (Merkel cell carcinomas) has not been cutaneous neoplasms. CMBC (especially ductal type) can be difficult to distinguish from studied. PSGC routinely. Treatment and prognosis for these is radically different, making accurate Design: Twenty surgically excised or biopsied primary cutaneous and metastatic histologic diagnosis more crucial. Some studies have evaluated these entities, but, to Merkel cell carcinomas were immunohistochemically studied using a monoclonal date, there have been no studies to determine the most useful immunohistochemical antibody against L523S/KOC. Cytoplasmic staining in more than 10% of tumor cells (IHC) profile to differentiate CMBC from PSGC. was considered positive for KOC expression. The immunostaining intensity was graded Design: Fourteen (14) cases of CMBC (13 ductal including 1 basal phenotype as weak, moderate, or strong. (DCMBC), and 1 lobular (LCMBC)), 12 cases of PSGC (4 eccrine carcinomas, 3 Results: Seventeen of 20 (85%) Merkel cell carcinomas expressed KOC, with 11 porocarcinomas and 5 microcystic adnexal carcinomas), 2 benign sweat gland neoplasm (55%) expressing KOC in greater than 90% of tumor cells, 3 (15%) expressing KOC in cases, and 2 primary breast cancer (PBC) cases from the past ten years are retrieved 50-90% of tumor cells, and 3 (15%) expressing KOC in 10-49.9% of tumor cells. The from archives. H&E slides were reviwed; blocks were selected and analyzed with the immunostaining intensity in 13 of 17 (76%) Merkel cell carcinomas was moderate to following IHC panel: mammaglobin, GCDFP-15, p63, basal cytokeratins (CK5, CK14, strong, and the immunostaining intensity in the remaining 4 (24%) was weak. & CK17), androgen receptor (AR), and PAX-5. ANNUAL MEETING ABSTRACTS 101A

Results: p63 is only weakly expressed in 8% DCMBC, while it is strongly expressed bulky disease (p=0.1967), Bcl2 expression (p=0.1967) and recurrence. CD10 expression in 83%PSGC. Basal cytokeratins show a similar phenotype with DCMBC showing 0 nearly correlated with a pure follicular morphology (p=0.0832; N=6). (CK14) to 16% (CK5 & CK17) expression and PSGC showing 83% expression with Conclusions: Bcl2 was expressed in 26.6% of PCFCL without significant statistical all 3 markers. Although none of the tumor cells showed nuclear staining for PAX-5, correlation with disease recurrence. Furthermore, the diffuse and nodular and diffuse 50% of the PSGC showed a distinct cytoplasmic/membranous (C/M) pattern (also seen patterns had similar disease recurrence rates, arguing against the utility of sub- in normal adnexal structures) not generally considered to be positive. Mammaglobin categorization of PCFCL into histologic subtypes. expression was 69% on the DCMBC. Results in Table 1. IHC stains in CMBC and PSGC 457 The Borderline Melanocytic Proliferation: A Clinical and Pathological IHC Stain DCMBC (%) (n=13) LCMBC (%) (n=1) PSGC (%) (n=12) Study with a Categorical Approach to Diagnostic Assessment Mammaglobin 69 0 17 GCDFP-15 39 0 8 JT Schaefer, CM Magro, AN Crowson. Weill Medical College of Cornell University, p63 8 (weak) 100 (weak) 83 (strong) New York, NY; St. John Medical Center, Tulsa, OK. CK5 16 0 83 Background: The borderline melanocytic tumor (BMT) is a morphologically and CK14 0 0 83 biologically indeterminate lesion manifesting worrisome architectural features with CK17 16 0 83 AR 54 100 17 cytologic atypia exceeding that encountered in nevi yet insufficient to warrant the PAX-5 (C/M) 0 0 50 designation of malignant melanoma (MM). In this study we examine the biologic behavior of deep-seated variants of the BMT via assessment of sentinel lymph node Conclusions: p63 and basal cytokeratins appear to be fairly sensitive and specific status and clinical outcome. markers to differentiate DCMBC from PSGC. One caveat with the basal cytokeratins Design: Twenty-eight patients with BMT (the majority with a depth exceeding 1 mm) is that ductal breast carcinomas with a basal phenotype are also likely to express basal received a wide local excision and sentinel lymph node biopsy between 2000-2006. Four cytokeratins. The potentially novel interpretation of PAX-5 in a cytoplasmic and/or categories of BMT were recognized: 1. BMT resembling nevoid melanoma (BMTNM); membranous pattern may provide a specific marker for the tumors of adnexal origin, 2. The atypical Spitzs tumor (AST); 3. Pigmented epithelioid melanocytoma (PEM); 4. and warrants further investigation. Since, the high expression of mammaglobin in BMT arising in a deep penetrating nevus (BMTDPN). CMBC is similar to previously reported expression in PBC, the expression of this Results: 4 patients were in the BMTNM category (M:F=1:3; mean age=27, range=15- marker appears preserved. 36), 12 in the AST category (M:F=6:6; mean age=22.4, range=3-58), 6 in the PEM category (M:F=4:2; mean age=23.5, range=3-39), and 8 in the BMTDPN category 455 Low-Fat and Fat-Free Pleomorphic Lipomas: A Diagnostic (M:F=5:1; mean age=22.3, range=14-36). The percentage of patients with positive Challenge sentinel nodes in each category were 25% (1/4), 25% (3/12), 17% (1/6) and 62% (5/8), MP Sachdeva, JR Goldblum, BR Rubin, SD Billings. Cleveland Clinic, Cleveland, respectively. The average time of follow-up was approximately 2.5 years. One patient OH. died of disease while the others are alive and well. In the one death attributable to Background: Pleomorphic lipomas (PL) are benign adipose tissue tumors that most widespread metastatic disease the lesion was initially interpreted as a DPN; however, commonly occur as circumscribed subcutaneous masses in the head and neck, shoulder, retrospective review was compatible with a BMTDPN. The review was prompted by a or back regions of middle-aged to elderly men. They are considered on a spectrum recurrence, which was morphologically compatible with a level V MM. with spindle cell lipomas (SCL) based on shared cytogenetic aberrations and similar Conclusions: The BMT occurs primarily in children and young adults. The highest histologic features including bland CD34-positive spindled cells, ropey collagen, and incidence of lymph node disease was in the deep penetrating nevus category. Although various amounts of mature fat. The presence of classic multinucleated floret-like giant in many cases the SLNs are negative, an initial aggressive clinical approach to the cells distinguishes PL from SCL. When only small amounts of fat are present within the borderline melanocytic proliferation may be important in limiting disease progression tumor, diagnosis can be challenging. We describe 7 cases of PL which posed diagnostic and could be curative. difficulties due to absent or diminished fat and report this as a variant of the previously reported “fat-free” and “low-fat” SCL. 458 Primary Cutaneous CD56 CD4 Positive T Cell Lymphoma; a Design: A review of 38 consultation cases diagnosed as PL revealed 7 cases in which fat Comparative Analysis with Four Cases of CD4 CD56 Positive Hematodermic was noted to be present in reduced (<5%) amounts (n=5) or absent (n=2). All histologic Neoplasm sections and immunohistochemical studies were reviewed. JT Schaefer, CM Magro, AN Crowson. Weill Medical College of Cornell University, Results: Five of the seven tumors presented as circumscribed subcutaneous masses New York, NY; St. John Medical Center, Tulsa, OK. in the head/neck (n=3), back (n=1), or shoulder (n=1) of men with a mean age of 59 Background: One category of cutaneous lymphoma is that of the natural killer and NK years (range 38-76 years). One case presented on the nose of a 48 year-old female and like T cell lymphomas. We encountered two cases of NK like T cell lymphoma exhibited was intradermal. Additional clinical information was not available for two cases. All a CD4 CD56 positive phenotype thereby mimicking a hematodermic neoplasm. tumors had multinucleated floret-like giant cells interspersed among bland spindled Design: Skin biopsies were obtained on both cases upon which comprehensive cells and ropey collagen. Mature adipocytes were present as isolated or rare clusters phenotypic and molecular assays were conducted. These cases were compared to 4 in five of the seven cases. Two cases were devoid of fat. Diffuse immunoreactivity for cases of known hematodermic neoplasm. CD34 was present in 4/4 cases tested. Results: The two case study patients, which were held to represent true NK like T cell Conclusions: “Low-fat” and “fat free” variants of PL may cause significant diagnostic lymphomas were both men, ages 62 and 76, demonstrating skin, bone marrow and challenge. Multinucleated floret-like giant cells are characteristic of PL, but not peripheral blood involvement accompanied by constitutional symptoms. Both died pathognomonic as such cells can also be seen in sclerosing liposarcomas and other of their disease within less than 12 months from presentation. The biopsies showed a nonlipogenic neoplasms. When fat is absent or present in reduced amounts, clinical pandermal mononuclear cell infiltrate which was CD2, CD3, CD4, and CD56 positive context and identification of classic histologic features are essential in distinguishing with a positive TCR beta rearrangement. One case was strongly EBER positive. The PL from malignant soft tissue tumors. four hematodermic neoplasm cases occurred in elderly males (mean age of 70 years). Clinical and light microscopic features were similar to our two index cases and as well 456 BCL2 Expression in Primary Cutaneous Follicle Center Lymphoma: there was variable expression of CD2 and CD7. However in no case was there CD3 Clinicopathologic Study of 15 Cases expression and the T cell receptor gene rearrangement assay demonstrated a germline ME Salama, A Ho, SL Perkins, JD Tward, DK Gaffney, RM Mariappan. University of configuration. As well there was CD123 expression and variable expression of TCL1 Utah, Salt Lake City; Beth Israel Deaconess Medical Center, Boston. oncogene, MXA and CD83, markers of plasmacytoid dendritic cells. Background: Primary cutaneous follicle center lymphoma (PCFCL) is defined as a Conclusions: CD4 CD56 positive NK T cell lymphoma is a rare form of NK like T cell tumor of neoplastic follicle center cells with a follicular, a follicular and diffuse, or lymphoma, which may manifest a clinical, light microscopic and phenotypic overlap a diffuse growth pattern by the WHO-EORTC. PCFCL, unlike nodal and secondary with hematodermic neoplasm. A broader panel of plasmacytoid dendritic cell markers cutaneous follicular lymphomas, were reported to lack bcl-2 protein expression or to may aid in the distinction in equivocal cases. only show faint bcl-2 staining in a minority of neoplastic B-cells with a more favorable outcome. We present histomorphological, and immunohistochemical correlation of 459 The Phenotypic Profile of Dermatomyositis and Lupus PCFC with disease recurrence after therapy. Erythematosus: A Comparative Analysis Design: Patients diagnosed with PCFCL between 1993 and 2006 from the University JP Segal, PA Chadwick, CM Magro. Weill Cornell Medical College, New York, NY. of Utah hospital in Salt Lake City, Utah were evaluated. The patients were selected if Background: The mechanisms involved in cutaneous inflammatory influx in connective they had a pathologic diagnosis of PCFCL and documented absence of extracutaneous tissue disease (CTD) are not fully elucidated. Recent work has recognized interferon disease at diagnosis or subsequently. 15 cases were identified with information sufficient signaling, with resulting recruitment of CXCR3 Th1 T-lymphocytes, as a key step for data analysis. Morphologic evaluation as well as a panel of immunostains including in the development of cutaneous lesions of both lupus erythematosus (LE) and CD20, CD3, CD30, Bcl6, CD10 MIB-1 and Bcl2 was performed (n=15). Follow dermatomyositis (DM). The purpose of this study is to further explore the phenotypic up data was available for 10 cases. Chi-square analysis was performed to evaluate profile of LE and DM. statistical significance. Design: Sixty cases represented by biopsy material from patients with classic Results: The mean patient age was 59 (range 47-81). 80% were males. The identified features of dermatomyositis (DM), systemic lupus erythematosus (SLE), discoid patterns of infiltrates are nodular (n= 4), nodular and diffuse (n=6) and diffuse (n=5). Bcl2 lupus erythematosus (DLE), and subacute cutaneous lupus erythematosus (SCLE) expression was noted in 4 cases (one nodular, 2 nodular & diffuse and one diffuse) and were examined by immunohistochemistry for expression of CD3, CD4, CD8, CD20, was seen in both a strong staining pattern (2 cases) and weak pattern (2 cases). Half of CD45RA, CD83, CD123, cutaneous lymphocyte antigen (CLA), FoxP3, CXCR3, the Bcl2 staining cases recurred. CD10 was expressed in 33% of cases and Bcl6 in 80% and MxA. of cases, but all cases had expression of at least one of these markers in the neoplastic Results: There was phenotypic overlap between DM and subtypes of LE. MxA staining infiltrate. The mean follow-up time was 34.7 months (range:3 to 100.9 months) and was seen in the majority of cases. In cases of DM and in many cases of LE the staining 40% of cases relapsed. There was no statistically significant correlation between clinical could be extensive. Among the positive staining cells were endothelium, keratinocytes, presentation (plaque vs. nodule; p=0.7468) histopathological patterns, number of lesions, 102A ANNUAL MEETING ABSTRACTS and inflammatory cells. The greatest extent of expression was seen in the setting of DM 462 Alteration of the Epigenetic Regulation of Chromatin Structure where endothelial cell staining was very conspicuous. The majority of all tested cases and Aggressiveness of Skin Melanoma showed a dominant CXCR3 Th1 lymphocytic infiltrate. Some cases of SLE and one S Staibano, M Mascolo, L Insabato, G Ilardi, C Mignogna, E Mezza, M Scalvenzi, G case of accelerated DM showed a lack of CXCR3 staining suggesting Th2 dominance. De Rosa. University Federico II of Naples Faculty of Medicine and Surgery, Naples, DM cases had the highest number of CD4+ T cells; there was a reduction in the CD4: Italy. CD8 ratio in cases of LE (particularly SLE) compared to DM, with CD8 dominance Background: Malignant melanoma is the most aggressive and lethal type of skin in some LE cases. In all cases the extent of CLA staining was low. DLE infiltrates had cancer, showing a progressive increase in incidence and mortality rates. Recently, a role significantly higher numbers of B cells. FoxP3+ regulatory T cells were never prominent, of chromatin organization and DNA damage repair process has been hypothesized for but were present in highest numbers in DLE cases. Plasmacytoid dendrocytes (CD83+ the progression of most of human solid malignancies. The resetting of the pre-existing and CD123+) were seen in the majority of DM and LE cases, manifesting accentuation chromatin structure during DNA synthesis, DNA replication, and/or DNA repair is around vessels and within the epithelium. mostly related to the Chromatin Assembly Factor 1 (CAF-1), a heterotrimeric protein Conclusions: An interferon dominant cytokine milieu is common in all forms of LE complex formed of three subunits (p48, p60 and p150). CAF-1 interacts directly with and DM, with the interferon-responsive protein MxA observed in a variety of cell types. proliferating cell nuclear antigen (PCNA) and has been proposed as a novel sensible There is a Th1 dominant milieu, though it may be variable in LE or decreased in DM proliferation marker in malignant tumors. We aimed to establishing if CAF-1 could associated with an accelerated decline in clinical course. The contribution of B cells have a role as a reliable prognostic indicator in skin melanomas (SM). to lesions of DLE is a constant feature and allows a phenotypic distinction from other Design: One hundred and two formalin-fixed, paraffin-embedded surgical specimens forms of CTD. While the influx of lymphocytes into the skin does not appear to be of SM were retrieved from the files of the Department of Biomorphological and related to CLA expression, diminished regulatory T cell function may play some role Functional Sciences, Section of Pathology, University Federico. We evaluated by in maintaining cutaneous lymphocyte populations. immunohistochemistry the expression of p60 and p150 CAF-1 subunits in a selected series of 80 cases of SM. Results were compared with the proliferation index evaluated by 460 Can Histomorphologic Findings Separate Merkel Cell Carcinoma PCNA, with clinical and pathological features of tumors and with the follow-up data. from Small Cell Carcinoma? Results: We found CAF-1 /p-60 over-expressed in almost all CMM studied, with SM Share, EM Cham, A Mohanty, TC Pereira, YL Liu, JF Silverman. Allegheny General values exceeding from two-to ten fold the level of expression of melanocytes of Hospital, Pittsburgh, PA; Evanston Northwestern Healthcare, Evanston, IL. normal control skin. This was in agreement with the trend of PCNA immunostaining, Background: Merkel cell carcinoma and small cell carcinoma represent malignancies with absolute values higher than those concerning PCNA. The expression of CAF- with very similar histologic neuroendocrine morphology. Although Merkel cell 1/p-150 was reduced in nearly half of SM with respect to controls. The statistical carcinoma is an uncommon cutaneous malignancy, it is important to distinguish it from analysis of results demonstrated a significant association between hyper-expression metastatic small cell carcinoma. Immunohistochemical (IHC) stains for CK 20, CK 7, of p60, hypo-expression of p150 and the occurrence of node and/or distant metastases and TTF-1 are used to differentiate these lesions. We evaluated if nuclear morphologic in SM patients. differences can help to establish the correct diagnosis. Small cell carcinoma has irregular Conclusions: Our results indicate that CAF-1 may have a role as new sensible nuclei with a fine and coarsely granular, “salt and pepper” neuroendocrine pattern of proliferation and prognostic marker in SM. diffusely dispersed chromatin. We have observed that nuclei of Merkel cell carcinoma are often more rounded with a evenly distributed finely granular chromatin, giving 463 Gadolinium-Induced Nephrogenic Systemic Fibrosis Is Associated the nuclei an overall “salt” only or “sanded” appearance. In this study, we tested staff with Insoluble Gd Deposits in Tissues: In Vivo Transmetallation Confirmed surgical pathologists and a surgical pathology fellow to determine if there are significant by Microanalysis nuclear morphologic differences between these two malignancies. C Thakral, JL Abraham. SUNY Upstate Medical University, Syracuse, NY. Design: Eight surgical pathologists and one surgical pathology fellow were blinded to the Background: Nephrogenic Systemic Fibrosis (NSF), first described in 2000, is an diagnosis and site and tested with digital images of 23 randomized cases, consisting of extremely debilitating systemic fibrosing disorder with extensive cutaneous involvement, 14 cases of Merkel cell carcinoma, and 9 cases of small cell carcinoma. All participants limited in occurrence to date in renal failure patients. CD34-positive circulating were asked to make the diagnoses in the absence of IHC stains. fibrocytes seem to play an important role in the pathogenesis of this disease. The Results: The average score of correct diagnoses on testing was 66.4%, with the single epidemiologic association with Gadolinium (Gd)-Based Magnetic Resonance Contrast highest percentage of 83%, and the lowest percentage of 54%. There was no significant Agents (GBMCA) came to light in 2006 and is further substantiated with case-control difference in test scores between levels of experience. studies. We investigated this by developing and applying a new automated scanning Conclusions: Although Merkel cell carcinoma was differentiated from small cell electron microscopy/ energy dispersive x-ray spectroscopy (SEM/EDS) method for in carcinoma in approximately 2/3 of the cases, our results indicate that a reliable diagnosis situ quantification of insoluble Gd-containing deposits in tissues involved with NSF. of Merkel cell carcinoma versus small cell carcinoma could not be consistently Design: Freshly cut paraffin block surfaces of biopsies are examined under standardized rendered based only on histologic nuclear morphology. Therefore, although these two conditions using the variable pressure mode of the SEM. Random search of the tissue neuroendocrine malignancies can often differ in their nuclear morphology, it is not allows in situ detection and semi-quantitative morphometric analysis with a spatial possible to make a definitive diagnosis without confirmatory IHC studies. resolution of less than 1 µm. The concentration is expressed as total Gd x-ray counts per second (cps)/ tissue area (mm2) analyzed. This records the multi-elemental composition 461 Immunohistochemistry in Ocular Carcinomas and spatial distribution at the histologic level for each detected feature. We also used BW Sramek, AE Lisle, TS Loy. University of Missouri-Columbia, Columbia, MO. TEM for ultrastructural analysis of a few cases. Background: The histologic distinction between ocular sebaceous carcinoma, poorly Results: To date, we have analyzed 57 skin biopsies from 29 patients with NSF, biopsied differentiated ocular squamous cell carcinoma, and ocular basal cell carcinoma can be a from 2 weeks to 3 years after GBMCA exposure. Eleven patients had sequential biopsies diagnostic challenge in small biopsy specimens. An appropriate immunohistochemical over time.Gd was detected in all the analyzed tissues, and not detected in any other skin 2 panel may help to differentiate these challenging lesions. biopsies analyzed. The concentration of Gd in tissues ranged from 1 to 2270 cps/mm . Design: To determine the distribution and utility of several immunostains in ocular Gd was found associated with Ca, P and sometimes Fe or Zn. Patients with sequential sebaceous carcinoma, poorly differentiated ocular squamous cell carcinoma and ocular biopsies showed persistence or increase of Gd in tissues. These apatite-like deposits basal cell carcinomas, formalin-fixed, paraffin-embedded tissue from several of each were found more in the subcutaneous fibrous septa than in the superficial dermis. was studied using an immunohistochemical technique. TEM identified the intracellular deposits in CD34-positive fibrocytes. The insoluble Results: Positive staining for CK7 was seen in 100% of the sebaceous carcinomas, deposits of Gd with co-associated elements clearly confirm in vivo transmetallation 77.8% of the basal cell carcinomas and 67.7% of the squamous cell carcinomas. One and dissociation of GBMCA. hundred percent of the sebaceous and basal cell carcinomas were positive for CAM 5.2, Conclusions: Our results demonstrate that slow clearance of GBMCA in a 3+ while only 83.3% of squamous cell carcinomas were positive. Using EMA, 100% of transmetallation promoting metabolic setting allows the release of toxic Gd ions squamous cell carcinomas and 80% of sebaceous carcinomas were positive, while basal and its deposition in tissues of renal failure patients. Its long term persistence can be cell carcinomas did not show immunopositivity. 100% of basal cell carcinomas and 80% a source for variable onset and/or continuation of disease even without any further of sebaceous carcinomas were positive for Ber-EP4, while no squamous cell carcinomas exposure to Gd. were positive. Finally, 77.8%, 20%, and 16.7% of basal cell carcinomas, sebaceous carcinomas, and squamous cell carcinomas, respectively showed immunoreactivity 464 Severe Architectural Disorder Is a Potential Pitfall in the Diagnosis for the androgen receptor. of Small Dysplastic Nevi *Immunohistochemistry in Ocular Carcinomas CA Torres-Cabala, JA Plaza, AH Diwan, VG Prieto. University of Texas - MD Anderson Androgen receptor CAM 5.2 EMA Ber-EP4 CK7 Cancer Center, Houston, TX. Sebaceous Carcinoma 20 100 80 80 100 Background: Little is known about morphologic features and significance of severe Basal Cell Carcinoma 77.8 100 0 100 77.8 architectural disorder in small, early dysplastic nevi (DN). It is also unclear if the Squamous Cell Carcinoma 16.7 83.3 100 0 50 histopathological characteristics of these nevi are similar to those seen in more * Percentage Positive developed lesions. Conclusions: Immunostains for EMA and Ber EP4 may be helpful in the diagnosis of Design: All cases of DN (n=355) biopsied at MD Anderson Cancer Center between ocular carcinomas. An EMA positive, Ber EP4 positive immunophenotype supports January and June 2006 were included in the study. The lesions were scored for sebaceous carcinoma, EMA positive, Ber EP4 negative result supports squamous architectural disorder and cytologic atypia using previously reported criteria cell carcinoma, and an EMA negative, Ber EP4 positive result supports basal cell (Architectural: circumscription, symmetry, single-cell growth, dishesive nests, pagetoid carcinoma. Immunostains for CK7, CAM 5.2, and androgen receptor are not helpful migration, and confluent growth. Cytologic: size and shape of melanocyte nuclei, in this setting. prominent nucleoli, size of melanocyte cytoplasm) (Human Pathol 1999; 30:500-505). Also evaluated were size, nevus type (junctional or compound), margins status, clinical features, history of melanoma, and follow-up. The DN were classified according to their sizes as small (equal or less than 3 mm) or large (greater than 3 mm in diameter). ANNUAL MEETING ABSTRACTS 103A

Results: 136 (38.3%) DN were small. Although large DN were predominantly compound Conclusions: p63 immunostaining constitutes a specific and accurate means of (64.6%), small lesions were almost equally junctional and compound. Grades of distinguishing MAC from DTE and BCCF. The scattered p63 positivity in MAC may architectural disorder and cytologic atypia were equally distributed in small and large be consistent with the postulated histogenesis of the neoplasm (dual follicular and DN. 40 lesions were diagnosed as DN with severe architectural disorder (DNSAD). sweat gland differentiation). DNSAD were slightly more frequent in females (57.5%), located on the back and lower extremities, junctional (62.5%), and large (67.5%). 13 DNSAD were small; of these, 467 Non-Mycosis Fungoides Cutaneous T-Cell Lymphoma: 84.6% were junctional. For comparison, DN showing mild and moderate architectural Reclassification According to the EORTC-WHO Classification disorder were predominantly compound. DN with severe cytologic atypia were mainly J Weaver, AK Mahindra, B Pohlman, T Jin, ED Hsi. Cleveland Clinic, Cleveland, large (8/10 cases) with no particular type predominance. 7 cases displayed both severe OH. architectural disorder and severe cytologic atypia; only one of these cases (a junctional Background: Non-mycosis fungoides (non-MF) primary cutaneous T-cell lymphomas lesion) measured less than 3 mm. No recurrences were detected at last follow-up. (P-CTCL) are a heterogeneous group of lymphomas. The WHO-EORTC classification Conclusions: In our series, small dysplastic nevi displaying severe architectural disorder of cutaneous lymphomas has divided these entities into distinct subgroups. We report are mainly junctional and tend to show only minimal, mild, or moderate cytologic atypia. a North American series of these tumors using this classification. Our data suggest that a number of dysplastic nevi may arise as junctional lesions with Design: Skin biopsies with lymphoma were identified over a 24-year period (1983- severe architectural disorder. Therefore, caution is needed when interpreting the degree 2007). All non-MF CTCL cases with available tissue for phenotyping, adequate clinical of architectural disorder in small melanocytic lesions in order to avoid overdiagnosis staging information, and follow-up were included. Cases were reclassified according of melanoma. to the WHO-EORTC classification for cutaneous lymphomas. Overall survival (OS) was evaluated with Kaplan-Meier analysis and log rank testing. 465 Unusual Variant of Desmoplastic/Spindle Cell Squamous Results: 44 non-MF P-CTCL cases were identified. 24 (54.5%) were cutaneous Cell Carcinoma of the Skin Mimicking a Scar. Clinicopathologic and peripheral T-cell lymphomas, (PC-PTL), which were further subdivided into the 3 Immunohistochemical Study of 4 Cases provisional entities: 1 cutaneous aggressive epidermotropic CD8+ cytotoxic T-cell EF Velazquez, SR Granter. Brigham and Women’s Hospital, Harvard Medical School, lymphomas (AECD8+), 2 cutaneous gamma/delta T-cell lymphomas (CGD-PTL), Boston, MA. 12 cutaneous CD4+ small/medium T-cell lymphomas (PTLCD4+), and 9 PC-PTL, Background: Desmoplastic cutaneous squamous cell carcinomas (SCCs) are unspecified. Also identified were 3 (6.8%) primary subcutaneous panniculitis-like rare but clinically significant neoplasms with an increased risk of recurrence and T-cell lymphomas (PSPTCL) and 17 (38.6%) primary cutaneous anaplastic large cell metastasis usually affecting sun-exposed skin of older patients. Histologically, they lymphomas (PC-ALCL). 10 cases of systemic T-cell lymphomas secondarily involving are characterized by elongated trabeculae of atypical epithelial cells associated with a the skin (S-CTCL) were seen including 9 cases of secondary cutaneous peripheral T-cell prominent (usually reactive) desmoplastic stroma. We describe an unusual variant of lymphoma (SC-PTL) and 1 case of secondary ALCL (S-ALCL). Non-MF P-CTCL had desmoplastic/spindle cell SCC in which the “desmoplastic” areas are predominantly a longer median OS (13.8 yrs) compared to SCTCL (2.5 yrs). Kaplan-Meier analysis composed of malignant (although relatively bland) spindle cells mimicking a reactive showed that PC-ALCL had the most favorable outcome (median OS 14.1 yrs) while scarring process. SC-PTL and PC-PTL had the shortest OS (median OS 2.5 and 2.4 yrs, respectively). Design: Four cases of spindle cell SCC with a predominant (greater than 80%) spindle PTLCD4+ cases appeared to have a relatively favorable course (median OS not reached). cell/desmoplastic pattern, devoid of significant atypia, were retrieved from our files. Consistent with recent reports, survival of the two CGD-PTL patients was very short Data analyzed was patient’s sex and age, tumor location, depth of invasion, mitosis, (1.8 and 2.1 months). perineural (PNI) and lymphovascular (LVI) invasion, squamous differentiation and Conclusions: Most P-CTCL can be classified according to the WHO-EORTC associated SCC in situ (SCCIS). Immunohistochemistry for AE1/AE3, CAM5.2, classification, and the relative frequency in this North American series is similar to 34betaE12, pan-keratin, p63 was analyzed. the European experience. Non-MF P-CTCL is a heterogeneous group with a favorable Results: All patients were male (age was 55, 71, 76 and 86). Locations included temple outcome compared to S-CTCL. The median OS of both PC-PTL and SC-PTL is (2 cases), cheek, and vertex of scalp. Three were primary tumors and one (cheek lesion) remarkably short, suggesting that these two entities have a similar biology and that the was a metastatic SCC in a radiation field. All cases affected the dermis, three cases distinction between PC-PTL and systemic PTL may be clinically irrelevant. On the other extended to the subcutaneous tissue and one infiltrated skeletal muscle. Tumors were hand, a subset - PTLCD4+ appear to have a very good prognosis similar to PC-ALCL predominantly composed of fascicles of bland spindle cells in a collagenized (in 2 cases (although follow-up is relatively short). “keloidal”) stroma with scattered pleomorphic cells and focal (less than 20%) squamous differentiation. Mitoses were 1-2/10 HPF. Blood vessels tended to be perpendicular 468 Expression of FOXP3+ Regulatory T-Cell Phenotype in Neoplastic to the skin surface. Three cases were associated with SCCIS. Spindle cells diffusely and Reactive Cells in Early Mycosis Fungoides expressed pan keratin, 34betaE12 and p63 with scattered expression of AE1/A3 and AK Witkiewicz, M Potoczek, M Kasprzycka, M Marzec, MA Wasik. Thomas Jefferson variable expression of CAM 5.2. One case showed PNI. LVI was not seen. University, Philadelphia, PA; University of Pennsylvania, Philadelphia, PA. Conclusions: We report 4 cases of an extremely unusual form of spindle cell SCC Background: Cutaneous T-cell lymphomas (CTCL) represents a heterogeneous group with prominent desmoplastic scar-like pattern mimicking a benign reactive process, of lymphoproliferative disorders of T cells homing to skin. Mycosis fungoides (MF) is particularly a scar. Differential diagnosis also includes desmoplastic melanoma. the most common variant of CTCL. Sezary Syndrome (SS) represents a leukemic form Immunostains for cytokeratins and p63 confirm the epithelial nature of the spindle of MF. Patients with CTCL frequently suffer from because of compromised cell component and highlight the infiltrative tumor borders. Careful search for atypical immuntiy. Experimental evidence indicates that regulatory T cells (T-regs) play features and squamous differentiation, immunohistochemical studies and sometimes important role in supressing immune response to pathogens as well as malignant cells. deeper sections are required to achieve the diagnosis of this variant of desmoplastic Expression of FOXP3 of the forkhead box transcription factor family is considered a SCC thay may otherwise be underdiagnosed. hallmark of T-regs. In this study we evaluated FOXP3 expression in MF tissues, SS cells and SS-derived cell lines. 466 p63 Immunohistochemistry in the Distinction of Microcystic Design: Twenty two skin samples and 17 lymph nodes from MF patients were analyzied Adnexal Carcimoma (MAC), Desmoplastic Trichoepithelioma (DTE), and by immunohistochemistry for the expression of FOXP3. Skin biopsies included 7 patch, Morphea-Form Basal Cell Carcinoma (BCCF) 9 plaque, and 6 tumor stage lesions. 9 of the lymph nodes showed involvement by MF CI Vidal, DE Burstein, RG Phelps, PO Emanuel. Mount Sinai Hospital, New York, and 3 contained MF with large cell transformation. Five lymph nodes showed only NY. reactive changes. Scoring of FOXP3+ cells was performed by counting the numbers of Background: Microcystic adnexal carcinoma (MAC) is a rare, malignant tumor. positive cells per 100 atypical cells in three representative areas at 40x magnification. Because of its locally aggressive behavior, distinction from histologic mimics such as FOXP3 expression was also analyzed in peripheral blood of 5 patients with SS and desmoplastic trichoepithelioma (DTE) and morphea-form basal cell carcinoma (BCCF) two SS-derived cell lines. is important and misdiagnosis can mislead treatment. The differentiation pathway of Results: The highest median numbers of FOXP3+ T-regs was seen in patch and plaque MAC has provoked considerable debate, with most agreeing that MAC shows follicular stage of MF (48/100 MF cells). FOXP3 expression was present both in MF cells and as well as eccrine differentiation. p63 is an epithelial stem-cell regulatory protein that small infiltrating lymphocytes. The number of positively staining MF and reactive plays a key role in the proliferation and differentiation cascade in stratified epithelia. Its lymphocytes markedly decreased at tumor stage (10/ 100 MF cells) and only small expression is consistently seen in basal/suprabasal cells of epidermis, hair matrix cells, number of FOXP3 positive cells was present in the lymph nodes involved by MF or MF outer root sheath of the hair follicle and tumors of follicular differentiation. with cell transformation (5/100 MF cells). SS cells and SS-derived cell lines expressed Design: We investigated immunohistochemical staining for the presence of p63 as FoxP3 upon stimulation with interleukin 2 (IL-2). a useful means of distinguishing MAC from DTE and BCCF. Archival, routinely Conclusions: Our data indicate that FOXP3 expression is very prominent in atypical processed slides were subjected to citrate-based antigen retrieval, exposure to anti-p63 and reactive cells in early stages of MF and decreases with the disease progression. monoclonal 4A4 and developed with a streptavidin-biotin kit and diaminobenzidine It also suggest that FOXP3 expression in MF cells is secondary to cytokine (IL-2) as chromogen. stimulation rather then represents a “fixed” phenotypic feature. T-reg phenotype may Results: Positive p63 staining was detected in all neoplasms examined (n=26). DTE at least in part explain the anergic, immunosuppressive nature of the disorder and may (n=10) and BCCF (n=10) consistently displayed diffuse p63 positivity, with staining of be important for inhibiting immune response against malignant cells, in particular at nearly 100% of tumor cells. In contrast, MAC (n=6) displayed a consistently scattered the early stages of CTCL. pattern of p63 staining within tumor nests. The scattered pattern seen in MAC could be further broken down as follows: (1) the selective staining of a single peripheral layer 469 Laminin/Integrin Expression Profile in Malignant Melanoma of p63-positive cells surrounding centrally located tumor cells that were p63-negative K Wong, MP Marinkovich, BA Horst. Stanford University School of Medicine, Stanford, or (2) tumor nests consisting of multiple contiguous p63-positive cells surrounding or CA; Columbia University School of Medicine, New York, NY. interspersed with p63-negative cells. Background: Malignant Melnanoma is the most common fatal skin cancer. It is the main cause of cancer death in Caucasian females aged 20-35 and shows the fasted rising 104A ANNUAL MEETING ABSTRACTS incidence among all cancers in the United States. Curative therapy is restricted to surgical excision during early tumor stages, and current treatment options of advanced disease are very limited. Studies on interactions of melanoma cells with the extracellular matrix focus on the role of matrix metalloproteinases such as MMP2, MMP9, and MT-MMP. The aim of the current study was to identify additional extracellular matrix components in primary melanoma and to establish their possible role in tumor invasion. Design: Primary melanomas were screened for laminin and integrin subdomains with specific antibodies by . Tumor cell lines with corresponding laminin and integrin-expression profiles were identified and selected for further studies of invasive capacity in vitro. Results: All primary tumors screened showed no expression of laminin chains α1, α2, α3, β2, β3, and γ2, neither within the tumor nor at the invading edge. A specific staining pattern was seen for laminin chains α5, β1, γ1, as well as for α6β4 integrin. Melanoma cell lines with a similar laminin and/or integrin expression profile were identified by Western Blot. Interestingly, in vitro invasion assays revealed a significant reduction of 472 Clinical Significance of Morphometric Measurements of Melanoma invasive capacity of melanoma cells in the presence of laminin α5 antibodies. Metastatic to Single Sentinel Lymph Nodes Conclusions: Primary malignant melanoma has a specific laminin and integrin- R Yaar, A Page, A Hestley, K Delman, GW Carlson, C Cohen. Emory University, expression profile. Interaction with these extracellular matrix components may impact Atlanta, GA. on the invasive capacity of tumor cells in vitro. Background: Sentinel lymph node (SLN) biopsy is a common procedure for staging patients with melanoma of >1 mm thickness. Immunohistochemistry for S100 470 Necrobiotic Xanthogranuloma: A Review of 17 Cases with protein and HMB45 facilitates examination of SLNs by highlighting small deposits Emphasis on Clinical and Pathologic Correlation of melanoma. Previous studies have suggested that certain morphometric features AJ Wood, MV Uraga-Wagner, JJ Abbott, LE Gibson. Mayo Clinic, Rochester, MN. of metastatic deposits may predict clinical behavior of the disease and help guide Background: Necrobiotic xanthogranuloma (NXG) is a rare disease (<100 reported treatment. The goal of this study is to identify a relationship between the morphometric cases) characterized by indurated, nontender xanthomatous nodules and plaques, characteristics of metastatic melanoma in single SLNs with disease relapse. typically involving the face, trunk, and extremities. It exhibits a chronic clinical course Design: S100 protein and HMB45 immunostained sections of SLNs from 122 patients and is usually refractory to treatment. The pathogenesis of NXG is poorly understood. with melanoma and a single, positive SLN were reviewed. Eleven morphometric Characteristic pathologic findings within the skin have been described, but there characteristics of metastatic deposits were each scored by two pathologists and compared exist no known correlations between specific histopathologic findings and clinical to clinical data for relapse. presentation or disease course. Despite a serum monoclonal gammopathy in most Results: Deposits stained positively for S100 protein and HMB45 in 98% and 84% cases, monoclonality of lymphocytes and plasma cells in skin biopsies from patients of cases, respectively. There were 41 (34%) relapses of any type and 37 (31%) distant with NXG has not been shown. relapses, which excludes cases with local relapse. Univariate analysis reveals that Design: A search of the Mayo Clinic Archives for patients with NXG between 1991 and percentage of lymph node replacement by melanoma (<1%, <5%), depth of melanoma 2002 was performed. A retrospective clinicopathological analysis was conducted on 17 deposits relative to the lymph node capsule, and intraparenchymal deposits in the absence patients with available clinical and histopathologic information. Immunohistochemical of subcapsular deposits, demonstrate a statistically significant correlation with relapse. In stains for kappa, lambda, CD3, CD20, GLUT-1, and IgG4 were performed on paraffin- multivariate analysis, head and neck primary site is associated with an increase in relapse embedded tissue in most cases. of any type (76% relapse rate, p=0.001), but morphometric measurements fall out of Results: The male-to-female ratio was 9:8 with an age range of 26-82 years at diagnosis significance. When only distant relapse is considered, multivariate analysis demonstrates (mean = 52). The majority (65%) showed involvement of the periorbital area, with the that small overall volume of melanoma deposits in a SLN (<5%) are associated with a trunk being the second most commonly affected site (47%). Twelve patients (71%) decreased incidence of relapse (20% relapse rate, p=0.02) and intraparenchymal deposits displayed a monoclonal gammopathy, three of which (18%) had multiple myeloma. in the absence of subcapsular deposits are associated with an increased incidence of Histopathologic examination of 12 cases demonstrated findings consistent with NXG, relapse (67% relapse rate, p=0.02). including a bandlike, zonated pattern of necrobiotic granulomatous inflammation, Conclusions: In addition to primary site, morphometric measurements of metastatic atypical giant cells, cholesterol clefts, and plasma cells. Kappa and lambda immunostains deposits in SLNs are associated with clinical relapse. Small volumes (<5%) of melanoma showed the lymphocytes and plasma cells to be polytypic in all cases. There was no and intraparenchymal deposits in the absence of subcapsular deposits are independent identifiable correlation between clinical presentation and specific histopathologic indicators of the incidence of distant relapse. These findings may help predict clinical findings. behavior and have therapeutic implications in patients with single positive SLNs. Conclusions: Our study did not demonstrate an appreciable correlation between clinical presentation and . We conclude that the skin lesions in necrobiotic 473 Immunohistochemistry of Cutaneous Extraocular Sebaceous xanthogranuloma represent reactive inflammation and do not correlate with the presence Carcinoma, an Update of monoclonal plasma cells or multiple myeloma. Furthermore, it appears that the A Zarineh, ML Wallace. Allegheny General Hospital, Pittsburgh, PA; Rabkin histopathology of NXG lesions is a poor predictor of a serum monoclonal protein. More Dermatopathology Laboratory, P.C., Pittsburgh, PA. studies need to be done to investigate the link between a serum monoclonal gammopathy Background: Sebaceous carcinoma (SC) is an uncommon tumor of pilosebaceous unit. and necrobiotic xanthogranuloma. They are more frequent as periocular neoplasms, leaving the extraocular variant even a more rare entity. There are conflicting reports regarding immunohistochemistry of 471 FOXP3-Expressing T-Regulatory Cells Increase with the Severity of these lesions. We intended to further study the immunoprofile of these tumors, as well Inflammation in Acute Graft-Versus-Host Disease of the Skin and Colon as their specific pattern of epithelial membrane antigen (EMA) reactivity. KN Wu, JL Farber, AK Wikiewicz. Thomas Jefferson University Hospital, Philadelphia, Design: 18 sebaceous carcinomas were selected from our files and their available PA. immunohistochemical stains were studied. Results were analyzed for 10 different Background: Acute graft-versus-host disease (GVHD) limits the effectiveness of markers. allogenic hematopoietic stem cell transplantation and affects skin, colon, and liver. Results: The reactivity frequencies were CK7 (3/18), CK 5/6(15/16), EMA (18/18), FOXP3 encodes a forkhead/winged helix transcription factor and is a key regulator carcinoembryonic antigen (CEA) (3/17), BER Ep4 (4/16), gross cystic disease fluid required for the development and function of the CD4+/CD25+ regulatory-T cells (T- protein (GCDFP-15) (0/17), Bcl-2 (11/16), D2-40 (16/16), AE1/3 (8/8), and p53 (3/4). regs). FOXP3-expressing T-regs are thought to suppress alloreactivity and protect against CAM 5.2, S-100 protein, melan-A/MART-1, CK20, chromogranin, and Synaptophysin GVHD, whereas lack of T-regs may result in an increased risk of GVHD. were also performed in some cases, when appropriate, to strengthen diagnostic certainty. Design: 44 biopsies (22 skin and 22 colon) from the same patients with grades 1-3 Analysis of the pattern of EMA immunostaining showed that all tumors (18/18) have acute GVHD were stained for FOXP3 (eBioscience cat#14-4777-82). Inflammation was EMA reactivity in vacuolated cells, followed by luminal cells (13/18), and germinative quantified by a 4-point scale: 0=no inflammation, 1=<25% of 20x field, 2=25-50%, and cells (11/18). Pattern of D2-40 positivity was peripheral (5/16) and diffuse (10/16). CEA 3=>50%. T-regs were quantified by a 4-point scale: 0=no cells per 20x field, 1=<5 cells was complicated with significant non-specific staining (7/17) in our experience. per 20x field, 2=5-10 cells, and 3=>10 cells. Conclusions: Positive EMA and negative GCDFP-15 immunostains remain the most Results: In both the skin and the colon, T-regs and inflammation were positively reliable markers for extraocular SC. D2-40 appeared as an adjuvant sensitive marker correlated. Among biopsies with low T-regs, the majority showed low inflammation of sebaceous carcinoma. Further comparative studies are required to evaluate the (skin 12/12; colon 6/10). By contrast, biopsies with greater T-regs showed greater value of this marker in dermatopathology. We suggest that the interpretation of CEA inflammation (skin 10/10; colon 12/12). Comparing the skin and the colon, in 12 be performed cautiously with attention to pattern and the area of reactivity. Our study patients the intensity of inflammation and density of T-regs were similar; in 8 patients was limited by number of available cases. they were more intense in the colon, and in 2 less intense in the colon. The results are summarized in Table 1. 474 Functional Correlation between Activation of MEK/ERK Signaling Conclusions: In acute GVHD of the skin and colon, T-regs increased with greater and Aberrant Expression of Tumor Suppressor p16 in Melanocytic inflammation. In turn, greater inflammation correlates with higher grades of GVHD. Lesions Thus, T-regs increased with higher grades of acute GVHD and reflected allograft Q Zhao, M Wahbah, B Kelly, M Eltorky, W Tang, J Dong. University of Texas Medical reactivity. Branch, Galveston, TX;. Background: NRAS and BRAF mutations, which lead to constitutive activation of the MEK/ERK signal transduction pathway, have been found at high frequencies in nevi and melanomas. Loss of function of tumor suppressor p16, mostly through gene mutation and ANNUAL MEETING ABSTRACTS 105A promoter hypermethylation is not uncommon in melanomas. The functional interaction formatting for viewing with open source multimedia framework viewers and .M4V between activated MEK/ERK signaling and loss of p16 in melanoma development is formatting for PC. A PC was formed by joining a free PC/WC host service (SwitchPod, largely unknown. Wizzard Media, Pittsburgh, PA). Files were transmitted to all residents and faculty. Design: Specimens of melanoma (n=10), metastatic melanoma (n=10), dysplastic nevi MMF were viewed using laboratory desktop computers and cell phones (Iphone, Apple, (n=10), compound nevi (n=10) and Spitz nevi (n=10) were retrieved, and sections Cupertino, CA). A 5 point scale survey (1 =lowest score to 5=highest) was transmitted stained immunohistochemically to detect MEK/ERK activation (phospho-MEK) and with each VQ to assess satisfaction with the platform. Compliance rates and diagnostic p16 expression. Markers of cell proliferation (Ki-67) and anti-apoptosis (BCL2) were accuracies were recorded. examined for correlation with status of MEK/ERK and p16 expression. The level of Results: There were 55 e-mail responses for the VQs, and 89 downloads from the positivity was scored by the percentage of stained melanocytic cells (0-100%) times podcast viewing platform over a period of one month. Twenty percent responded to the the staining intensity (1-3) and was statistically analyzed. unsolicited VQs, and 100% of those that responded participated >=2 occasions. Results Results: Phospho-MEK expression is highest in primary melanomas (score: 77) and of the VQs showed approximately 80% correct answers for both residents and faculty. dysplastic nevi (score: 68), whereas metastatic melanomas have much lower staining Satisfaction scores were: Image quality – 4.4 (range 2-5); Sound quality-4 (range – 0- activity (score: 27). Spitz and compound nevi have low levels of phospho-MEK 5); Ease of use – 4.7 (range 3-5); Satisfaction with format- 4.7 (range 3-5). Negative expression (score: 3 and 11, respectively). Compound, dysplastic, and Spitz nevi are comments were mostly related to suboptimal sound transmission (14.5%). diffusely positive for p16, with average scores of 240, 222, and 216, respectively and Conclusions: MMF including images and sound that can be transmitted via e-mail or exhibit both nuclear and cytoplasmic staining in > 50% positive cells. The expression posted for PC or WC, are a useful tool for PRE. The MMF can be viewed from personal of p16 decreases in primary melanomas (score:155), and has lowest level in metastatic computers, selected cell phones, or other portable devices that allow internet access. melanomas (score: 30). Colocalization of phospho-MEK and p16 is present in < 15% The use of this methodology in PRE is discussed. positive cells in melanoma and dysplastic nevi. Interestingly, we found that levels of BCL2 closely correlate with p16: the expression of BCL2 follows the same trends of 477 and Patient Safety (GEPS) Residents’ Teaching p16 in the compound and dysplastic nevi which were expressed strongly to moderately, Conference positive in 89% cells and had an intensity of 2.6 (score: 231). The proliferation index TC Pereira, KM Jasnosz, JF Silverman. Allegheny General Hospital, Pittsburgh, PA. with Ki-67 is slightly higher in melanomas (8-10%) than nevi (0-5%). Background: We recently established a monthly conference in our department for Conclusions: Low levels of phospho-MEK in nevi indicate that NRAS and BRAF residents’ education: the Gross Examination and Patient Safety (GEPS) Conference. mutations are not sufficient to induce MEK/ERK signaling activation. Co-existence The coordinator is an attending pathologist, with participation by the residency program of phospho-MEK and loss of p16 in melanomas suggest their functional interaction director and the director of anatomic pathology. Attendance is mandatory for all in maintaining the malignant phenotypes of these cells. The correlation between p16 pathology residents. Cases with problems that occurred in the gross room are flagged by and BCL2 needs to be further explored for functional significance. (* These authors the faculty, pathologist assistants, transcriptionists, histotechnologists, and/or residents. contribute equally to this project). Each case is then presented in an anonymous fashion, with the format consisting of glass slides, gross photos, and/or copy of the gross description. Pertinent references are discussed including sections from manuals of gross examination, textbooks of surgical Education pathology, CAP checklists for inspection and accreditation, and literature on quality assurance, patient safety and medico-legal aspects of pathology. The goal of this teaching 475 Pathology Education as a Web Application: An Advanced Tool for conference is process and performance improvement to help ensure patient safety. the Future Pathologist Design: We reviewed the cases presented at the conference over the past 4 months and RA Cecil, DM Jukic, RC Zalme. UPMC, Pittsburgh, PA; University of Pittsburgh, classified problems in gross examination and reporting. We analyzed individual and Pittsburgh, PA; AirForce, Keesler AFB, MS. system errors and described the corrective actions implemented. Background: As part of the Integrated Medical Information Technologies System Results: There were 55 cases presented, categorized into 9 different types of problems (IMITS) Telepathology Project, a reference database of pathology cases was developed including incomplete/inadequate gross examination (10 cases); incomplete/inadequate to further pathology education in the highly distributed Air Force medical environment. gross description (12 cases); improper labeling/identification (5 cases); too few sections Customized software displays digital slide pathology images in context, both with submitted for histologic examination (3 cases); too many sections submitted (1 case); realistic background information and added notes and annotations from an experienced delay in processing (6 cases); inadequate triage of tissue (3 cases); sections inadequate pathologist. The instructor can set up tests that send the student directly to an area of for optimal histologic processing (13 cases) and other issues (2 cases). Examples of interest on an image, display essay and multiple choice questions, and save the answers system errors identified include suboptimal work flow of specimens in the gross room, for later grading. The graded results are immediately available through the system for lengthy and redundant gross descriptions due to templates that needed revision, and the student’s review. delay in specimen processing due to lack of priorization for grossing specimens. Design: A database in MS SQL Server was developed and loaded with cases containing Conclusions: We report our novel monthly residents GEPS conference. We propose anonimized clinical history, histologic, and diagnostic information. Slides from those it as a constructive, non-threatening educational conference for process improvement cases were scanned on various commercial Whole Slide Imagers: Aperio’s ScanScope, that especially addresses problem-prone situations. We believe this type of conference Zeiss’s Mirax (Trestle DSM), and Hamamatzu’s Nanozoomer. The images were stored provides a unique opportunity to help residents identify common and uncommon on a SAN and the urls loaded into the database. The web application, written in MS individual and system errors in order to insure higher quality pathologic gross C# language using .NET framework 2.0, invokes an appropriate viewer when an examination and thereby improve medical care and patient safety. image is selected. Demonstration of the system will focus on oral and dermatological pathology, as the principal investigators for the Air Force and UPMC respectively 478 An Interactive Web-Based Teaching Tool for practice those specialties. VVB Reddy, KT Bradley, BA Webber, ND Raju, VA Varma. University of Alabama at Results: The centralized server allows student users and instructors to access the Birmingham, Birmingham, AL; Emory University, Atlanta, GA; D3T Technology, repository at their convenience, using readily available web browsers to review images Inc, Hyderabad, India. in context of the case diagnostic information. Both the student and the instructor Background: Although numerous online resources of medical knowledge are available, have the ability to operate asynchronously, accessing the system without concern for considerable variability exists in terms of depth and quality of content, website design, interrupting critical tasks. Background procedures collect statistics transparently for and features that are relevant to medical practice. We present a novel interactive teaching feedback to improve the system. and reference hematopathology tool for pathologists and clinicians. Conclusions: Users at all levels will benefit from access to digital slide images organized Design: This interactive atlas and text of hematopathology was built on a relational in a repository categorized by type of tissue and disease. Student users can benefit database designed to handle structured medical knowledge. The description of each even more by taking the tests, and then seeing feedback on their diagnoses from an entity is parsed into units: Key Features, Epidemiology, Clinical, Histopathology, experienced pathologist. Immunophenotype, Genetics, Prognosis, etc. A bi-directional interface provides a seamless connection from this knowledge base to PubMed. An author interface was 476 The Use of Multimedia Files, Podcasts, and Webcasts in Pathology designed to allow direct entry of text, images, and metadata into the database. A Education permission system was installed to manage the work flow of authoring, editing, and GE Galliano, AM Marchevsky. Cedars-Sinai Medical Center, Los Angeles, CA. publishing. Server software was implemented to automatically create an additional Background: Multimedia files (MMF) including video and sound have been used customized version for hand held devices and cell phones. in pathology resident education (PRE) but have required considerable investments Results: This electronic atlas of hematopathology can be viewed on any internet in hardware and software and specialized technical support.The widespread use connected computer or wireless device. The content includes highly organized text, high of hand held devices such as cell phones and PDAs have stimulated the expansion resolution image thumbnails that can be enlarged, a search engine that allows searches of technologies for the development of portable MMF that can be distributed with based on any combination of clinical, pathologic or image criteria, and references inexpensive software. The use of Podcasts (PC) for educational activities in PRE has that are directly linked to PubMed abstracts. In addition, the system develops links to not been previously reported. up-to-date PubMed references for each subheading of the disease entity. A differential Design: Ten MMF including videos recording the examination of a pathology slide diagnosis (DDx) link displays side by side comparisons of images and Key Features under light microscope and audio descriptions were prepared using a digital camera, for relevant lesions, and end users can rapidly create their own customized DDx tables. readily available presentation software (PowerPoint, Microsoft, Redmond, WA), and On preliminary demonstration surveys, this tool was well received by pathology and low cost software (Quicktime Pro, Apple, Cupertino, CA).The MMF were developed oncology trainees as well as practitioners. in “pairs”: video quizzes (VQ) and corresponding teaching files providing “answers”, Conclusions: This system provides an electronic book that is visually rich, offers descriptions and diagnostic pearls. The size of the VQ was maintained to allow for file dynamic pages, is easily customizable, and provides realtime access to literature updates. transfer by e-mail via free SMTP systems (Simple Mail Transfer Protocol, <15 MB) For the authors, it provides an intuitive authoring tool for updating the content. The or posting for webcasting (WC) and PC. Files were converted into .AVI and .MOV hand held device/cell phone version provides access to knowledge in the clinics and at the bedside. As a possible future application, the architecture of the database allows