40 XXVI Congress of the IAP: Abstracts Dermatopathology was performed employing a heat-based antigen retrieval technique using the following monoclonal antibodies/to the following CT antigens: mAb MA454/MAGE-A1, M3H67/ 167 THE INTERPRETATION OF BENIGN BIOLOGIC BEHAVIOR MAGE-A3, 57B/MAGE-A4, CT7-33/CT7 (MAGE-C1), E978/NY-ESO-1, CT10#5/CT10 FOR KERATOACANTHOMA VERSUS CUTANEOUS SQUAMOUS CELL (MAGE-C2). In a subset of 8 Spitz nevi, the following mAbs were used for the analysis of CARCINOMA, USING A PANEL OF ANTIBODIES AGAINST: EGFR , P21 RAS, MDAs: HMB45/gp100, A103/Melan-A, T311/tyrosinase. P53 , CYCLIN D1 Results: No immunopositivity was seen with any of the tested anti-CT antigen mAbs Ahmad Zahi Al-Chawaf, Faculty of Medecine, Hama, Syria; Bassam Al-Hallani, Faculty (MA454, M3H67, 57B, CT7-33, E978, CT10#5) in any of the 32 Spitz nevi. However, all of Medecine, Homs, Syria three mAbs to MDAs (HMB45, A103, T311) showed strong and homogeneous staining in Background: The keratoacanthoma (KA)is a relatively common tumor which most often the subset of 8 Spitz nevi which were analyzed. occurs on the sun – exposed areas of light skinned individuals of middle age and older. Conclusion: The differential diagnosis of Spitz nevi versus malignant melanoma can pose This tumor may regress spontaneously, so recognition of the true nature of this tumor is of a diagnostic dilemma in surgical pathology. Markers such as mAb HMB45, A103 and T311 considerable practical and biological importance. Could it be named an aborted squamous indicate melanocytic lineage and their immunopositivity in the present lesions is consistent cells carcinoma? with the diagnosis Spitz nevus. However, they do not contribute to the distinction between Design: 24 cases of keratoacanthoma and 26 cases of SCC were immunostained for EGFR, benign and malignant. Previous analyses confi rmed the tumor-associated expression of P21 ras, P53, Cyclin D1 oncoprotein using a Dako Autostainer Plus. Lesions were scored CT antigen expression on a protein level. In melanomas, including so-called `Spitzoid for positive staining: diffuse basal and suprabasal staining and focal basal and suprabasal melanomas`, up to 50% were immunopositive for some CT antigen. The negative staining. immunoreaction of all our anti CT antigen reagents in the present series of Spitz nevi Results: The expression of P53(mutant gene)showed a great difference between SCC and confi rms the benign biology of this cutaneous lesion. Conversely, any expression of CT Keratoacanthoma (20/26 – 80% in SCC versus 4/24 – 16% in KA) (P<0.01) -2/4 of KA antigens on a protein level in a lesion regarded as Spitz nevus should raise serious doubts cases were reevaluated as SCC (KA –like SCC). The expression of P21 ras was more about its nature and diagnosis and rather speaks for the presence of a malignant tumor, evident in KA versus SCC (14/24 -58 % in KA versus 5/26- 19% in SCC (P < 0.05). EGFR particularly melanoma. was negative in all cases of KA and SCC but focally expressed in the neighboring reactive epithelium. Cyclin D1 showed more evident staining (focal expression) in SCC (10/26 170 PRIMARY MALE NEUROENDOCRINE NIPPLE ADENOCARCINOMA -38% in SCC versus 4/24 – 16 % in KA). SIMULATING MERKEL CELL CARCINOMA – A DIAGNOSTIC PITFALL Conclusion: Our results refer to the decisive role of P53 mutation in the development Klaus Busam, Memorial Sloan Kettering Cancer Center, New York, NY, United States of SCC and its invaluable role in setting down a convincing diagnosis of SCC. P21 ras Background: Male breast cancer is a rare entity accounting for <1% of all breast cancer was more defi nitive in KA. EGFR is expressed more in reactive and benign epidermal cases in the United States, but has a rate that has been rising over the last 25 years. Nipple growths and has no role in both KA and SCC. P53 mutation is critical and decisive in the skin/subcutaneous tumors in males are even rarer. Likewise, a true neuroendocrine development of cutaneous malignancy. Cutaneous malignancy may be ascribed more to carcinoma of the breast, defi ned as >50% of tumor cells staining for either chromogranin mutation in nuclear oncoproteins. or synaptophysin, is not a common entity, usually occurring in older females. Design: We present a case of a 70 year old male with a slowly growing nipple mass which 168 METASTATIC OVARIAN TUMOR ( KRUKENBERG`S TUMOR ) FROM had enlarged over the prior 1 ½ years. PRIMARY MALIGNANT MELANOMA OF THE SKIN: A CASE REPORT Results: The histology consisted of nests, trabeculae and sheets of basaloid cells with Zuhir Al-Shehabi, Department of Pathology ,Tishreen University, Lattakia, Syria; Lina rare abortive gland formation and a pushing edge. The case was originally misdiagnosed Al-Soufi , Department of Dermatology, Tishreen University, Lattakia, Syria as a Merkel Cell Carcinoma, based largely on histologic morphology. Strong staining for Background: Krukenberg tumor is classically defi ned as a metastatic signet ring cell synaptophysin (in greater than 50% of cells), CD56, keratins AE1:AE3 and Cam 5.2, as carcinoma arising in the stomach or gastrointestinal tract and metastasizing to the ovaries. well as ER and PR was noted. Myoepithelial cells within in-situ areas were identifi ed using Other primary sites have been described, and a few cases have no detectable primary. stains for calponin and 4A4, supporting a primary mammary duct origin. Additionally, a Design: We report a case of a 48 –year –old female with bilateral metastatic ovarian substantial portion of cells stained for GCDFP-15, confi rming some overlap with sweat tumors from primary malignant melanoma of the left thigh who underwent hysterectomy duct differentiation. & bilateral oophorectomy in the University Hospital of Tishreen University, Lattakia, yria Conclusion: To the best of our ability, although reported in the male breast, no case in November 2005. For confi rmation we used select immunostains, including cytokeratin of primary nipple neuroendocrine carcinoma in a male patient has been reported in the (CK), S-100 & Melan A. literature. The gender of the patient and association with the skin of the chest wall likely Results: The patient had an excisional biopsy in June 2003 for a pigmented tumor on contributed to the original misdiagnosis of Merkel Cell Carcinoma in this patient. the left thigh, followed by regional lymph node dissection. The pathological diagnosis was superfi cial spreading malignant melanoma (Clark level III). The regional lymph 171 DISTINCTION OF BENIGN SEBACEOUS PROLIFERATIONS FROM nodes were negative for metastasis. In November 2005 the patient presented with an SEBACEOUS CARCINOMAS BY IMMUNOHISTOCHEMISTRY acute abdomen. On laparotomy both right and left ovaries were enlarged, each measuring Erik Cabral, Stanford University Medical Center, Mountain View, CA, United States; 23x17x15 cm in maximum dimension. The histological examination revealed metastatic Aaron Aurbach, Armed Forces Institute of Pathology, Washington, DC, United States; malignant melanoma and the neoplastic cells were positive for S-100 and Melan –A and J. Keith Killian, National Cancer Institute, Bethesda, MD, United States; Terry Barrett, negative for CK . UT Southwestern Medical Center, Dallas, TX, United States; David Cassarino, Stanford Conclusion: To our knowledge, we report a rare case of Krukenberg`s tumor from University Medical Center, Palo Alto, CA, United States primary malignant melanoma of the skin. Review of the literature showed no cases of such Background: Sebaceous proliferations, including sebaceous adenomas, sebaceomas, and metastatic ovarian tumor. carcinomas, are histologically distinctive adnexal tumors with a spectrum of biological behavior ranging from benign to frankly malignant. The histologic distinction between 169 EXPRESSION OF CANCER TESTIS (CT) AND MELANOCYTE sebaceous adenomas and carcinomas may be challenging, especially in cases showing DIFFERENTIATION ANTIGENS (MDA) IN SPITZ NEVI atypical features and in small or partial biopsies. We studied multiple oncogenic and Nille Behrendt, Ackerman Academy of Dermatopathology, New York, NY, United States; therapeutic proteins by immunohistochemistry in order to identify differences in expression Achim A Jungbluth, Ludwig Institute for Cancer Research, New York, NY, United States; between benign and malignant sebaceous proliferations. Klaus J Busam, Department of Pathology Memorial Sloan-Kettering Cancer Center, New Design: A total of 27 cases, including 9 sebaceous adenomas, 4 sebaceomas, 8 sebaceous York, NY, United States; Sandra B Castelli, Ludwig Institute for Cancer Research, New carcinomas, and 6 cases of sebaceous hyperplasia, were examined by immunohistochemistry York, NY, United States; Geoffrey G. Gottlieb, Ackerman Academy of Dermatopathology, with antibodies directed against Ki-67, bcl-2, p53, p21WAF1, p27Kip1, c-erbB-2 (Her-2/ New York, NY, United States neu), CD117 (c-kit), cyclin D1, MDM2, CD99, MLH-1, and MSH-2. Background: Spitz nevi are rare melanocytic lesions primarily in children and young Results: We found that sebaceous adenomas and sebaceomas stained similarly to sebaceous adults, which can be diffi cult to differentiate from malignant melanoma. CT antigens such hyperplasia, while carcinomas had statistically increased levels of p53 (50% versus 11%, as the MAGE-gene family, CT7 and NY-ESO-1 resemble a group of recently identifi ed respectively, p < 0.05) and MIB-1 (average 30% versus 10%, p < 0.05). The carcinomas tumor-associated antigens, which are expressed in various malignant