Treatment of Benign and Atypical Nevi with the Normal

STUDY Treatment of Benign and Atypical Nevi With the Normal-Mode Ruby Laser and the Q-Switched Ruby Laser Clinical Improvement but Failure to Completely Eliminate Nevomelanocytes

Daniella Duke, MD, MPH; H. Randolph Byers, MD, PhD; Arthur J. Sober, MD; R. Rox Anderson, MD; Joop M. Grevelink, MD, PhD

Objective: To evaluate the effect of normal-mode and melanocytes in a measured length of basement mem- Q-switched ruby laser light (694 nm) on nevomelano- brane zone. cytes of benign, atypical, and congenital nevi. Main Outcome Measure: Three individual readings Design: Half of the lesion of each of 31 nevi was treated (number of melanocytes per unit length) were taken on with either the Q-switched ruby laser or the normal- both the control and treated halves and then compared mode ruby laser or both; the other half of the lesion was to quantitate treatment effect. All analyses used aver- covered with aluminum foil and was not treated. ages from 3 measurements. A Student paired t test was used to compare the treated and untreated sides. Setting: A university-affiliated, hospital-based laser center. Results: Sixteen (52%) of the nevi showed a clinically visible decrease in pigment on the treatment side at the Patients: Sixteen patients with a total of 31 melano- 4-week follow-up visit. cytic nevi were enrolled in the study. Conclusion: No lesions had complete histologic re- Interventions: All nevi were evaluated by at least 2 moval of all nevomelanocytes. Therefore, 1 or 2 laser treat- dermatologists to assess the degree of clinical atypia. ments are not sufficient to cause complete removal of a Photographs were taken before and immediately after lesion either clinically or histologically. treatment and at each follow-up visit. The digital imaging system was used to evaluate the number of Arch Dermatol. 1999;135:290-296

T THE present time, the somes are destroyed as a result of both the standard approach to the thermal and photoacoustic effects of the removal of benign and laser energy. The Q-switched ruby laser atypical nevomelanocytic (QSRL) has been used to treat pigmented lesions is surgical exci- lesions, such as cafe´ au lait macules, len- Asion. Patients who have prominent atypi- tigenes, nevi of Ota, and tattoos, and has cal nevi may undergo numerous exci- been studied in the treatment of acquired sions resulting in multiple scars. and congenital nevi.3-11 The normal- From the Dermatology Laser mode ruby laser (NMRL), with a longer Center (Drs Duke, Anderson, Furthermore, some nevi are in cosmeti- and Grevelink) and Department cally sensitive anatomic locations where pulse duration of up to 3.0 milliseconds, of Dermatology (Dr Sober), complete surgical excision is difficult to has been studied in the treatment of hair 12 13,14 Massachusetts General achieve or leaves a noticeable scar. There- follicles and congenital nevi. Con- Hospital, Harvard Medical fore, additional treatment options for cern for malignant transformation or School, Boston; nevomelanocytic lesions would be of value. incomplete removal of benign or atypical Dermatopathology Section, Pigmented cells in the epidermis or nevus cells has limited the use of laser Department of Dermatology, dermis can be selectively targeted and de- treatment of these nevomelanocytic Boston University School of stroyed by laser light of a specific wave- lesions. Medicine (Dr Byers); length and pulse duration, as described by Department of Dermatology, the theory of selective photothermoly- Yale Medical School, New 1,2 Haven, Conn (Dr Duke); and sis. Q-switched lasers with high peak powers and pulse durations in the nano- This article is also available on our Eastern Connecticut Web site: www.ama-assn.org/derm. Dermatology, Groton second range target melanosomes in me- (Dr Duke). lanocytes and keratinocytes. Melano-

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©1999 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/25/2021 PATIENTS AND METHODS QSRL, healed for 2 weeks, and then received treatment to the same half of the lesion with the NMRL. Four weeks following the last laser treatment, the en- Sixteen patients with a total of 31 melanocytic nevi were tire lesion was photographed and excised using a stan- enrolled in the study. Patients were recruited from the dard surgical elliptical excision procedure and 3-mm mar- dermatology, pigmented lesion, and laser clinics of Mas- gins. One nevus was excised 3 months following laser sachusetts General Hospital, Boston. Inclusion criteria treatment. The laser-treated side was identified by a su- were age 18 to 75 years, consent to participate in the ture. Patients had follow-up skin evaluations 2 weeks, 6 study, and a desire to have a mole removed. Patients months, and 1 year following the excision. Clinical re- were excluded who were mentally incompetent, prison- sponse was based on comparison of pretreatment and post- ers, pregnant, under 18 or over 75 years old, or immu- treatment (4 weeks) photographs of the nevi. Grading of nocompromised or who had an active infection or a pho- clinical response was based on a “positive response” or “no tosensitivity disorder. response” dichotomous scale. All nevi were evaluated by at least 2 dermatologists Tissue sections were cut 3 mm thick, deparaffinized to assess the degree of clinical atypia. Clinical atypia was in xylene, rehydrated in alcohol, and washed with defined by irregular pigmentation or border, a recent change phosphate-buffered saline (PBS). No proteolytic diges- in the lesion, assymetry, and size greater than 5 mm. Only tion was performed. The monoclonal anti–tyrosinase- benign-appearing, congenital, or mildly to moderately atypi- related protein antibody (Mel-5) (Signet Laboratories cal nevi were selected for the study. Nevi of severe atypia Inc, Dedham, Mass) was used to detect melanocytes at a clinically or with any concern for melanoma or nevi on the dilution of 1:40. Sections were incubated with the Mel-5 face, palms, soles, or genital area were excluded from the antibody overnight in a humidified chamber at 4°C. study. In addition, nevi were selected that were relatively After being rinsed 3 times in PBS, the sections were symmetric; lesions with eccentric pigment dots or a sharply incubated with biotin-labeled anti–mouse IgG antibody asymmetric border were excluded. If a nevus was deemed for 30 minutes and then washed again 3 times in PBS. appropriate for the study, a consent form was reviewed with The sections were subsequently incubated with alkaline and signed by the patient. This study was approved by the phosphatase–labeled avidin, washed again 3 times in Subcommittee of Human Studies at Massachusetts Gen- PBS, and colorized with new fuchsin substrate system eral Hospital. (Dako Corp, Carpinteria, Calif). Sections were then Photographs were taken before and immediately af- counterstained with hematoxylin. Immunohistochemical ter treatment and at each follow-up visit. Each nevus was control sections were incubated with secondary antibody marked to designate half of the lesion for laser treatment alone. and half of the lesion for no treatment (control side). As The control halves of the nevi were analyzed to ren- the lesions selected were relatively symmetric, the control der a pathologic diagnosis and to compare with the side reflected the clinical appearance of the treatment side. treated halves. The treated and untreated halves were Half of each nevus received laser treatment. The la- evaluated for the presence of fibrosis and/or other sers used were either the QSRL (Spectrum Medical Tech- reparative changes and changes in the junctional compo- nologies Inc, Palomar Medical Products Inc, Lexington, nent (referring to lentiginous melanocytic hyperplasia), Mass) or the NMRL (Epilaser; Spectrum Medical Tech- the dermal component, dermal pigmented type A cells, nologies Inc, Palomar Medical Products Inc). The QSRL, pronounced dermal nests, pigmented melanophages, with a pulse duration of 40 to 60 nanoseconds and wave- and depth of the dermal nests (measured from the over- length of 694 nm, was used at a fluence of 7.5 to 8.0 J/cm2 lying granular cell layer). Nevi for which a decrease in with a spot size of 5 mm. The NMRL, with a pulse dura- the junctional and/or dermal component was noted by tion of 3 milliseconds and wavelength of 694 nm, was used light microscopy were evaluated with a digital imaging at a fluence of 40 J/cm2 and a spot size of 7 mm. The NMRL system (IPLab Spectrum, version 3.0, Signal Analytics handpiece had a sapphire tip cooled to 10°C to limit epi- Corp, Vienna, Va) to quantitate nevomelanocyte reduc- dermal heating. Partial overlap of the pulses, ranging in num- tion. The digital imaging system was used to evaluate the ber from 3 to 8, avoided skip areas within the treatment number of melanocytes in a measured length of basement site. A strip of metal foil covered the control area to pre- membrane zone. Three individual readings (number of vent any irradiation of the untreated half of the nevus. melanocytes per unit length) were taken on both the con- Wound care included bacitracin ointment applied twice daily trol and treated halves and then compared to quantitate for 3 to 5 days. the treatment effect. The thickness of the dermal compo- Following placement of foil to cover half of each of nent was evaluated by measuring from the granular cell the lesions, 4 nevi (group 1) were treated with the QSRL layer to the top and bottom of the dermal nests in 3 differ- and 22 nevi (group 2) were treated with the NMRL. Three ent areas of both the control and treatment sides. All nevi (group 3) were treated first with the NMRL, immedi- analyses used averages from 3 measurements and then a ately followed by treatment to the same half of the lesion Student paired t test to compare the treated and untreated with the QSRL. Two nevi (group 4) were treated with the sides.

The objective of this study was to evaluate the clini- RESULTS cal and histologic effect of NMRL and QSRL on nevomelanocytic lesions, including acquired, atypical, and con- Sixty-two percent (n = 19) of the patients were women; genital nevi. The degree to which the 2 lasers remove 38% (n = 12) were men. Nineteen percent (n = 6) of the melanocytes was compared. Histologic characteristics of patients had a history of atypical nevi, a family history nevi were correlated with treatment efficacy. of melanoma, and/or a personal history of melanoma. The

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©1999 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/25/2021 Table 1. Study Groups, Categorized by Type of Laser Used for Treatment and by Type of Nevus*

Group 3 Group 4 Group 1 Group 2 (QSRL + NMRL) (QSRL, Then NMRL) Type of Nevus (QSRL) (NMRL) (Same Session) (2-wk Interval) Benign acquired (n = 10) 2 8 0 0 Atypical (n = 12) 2 9 0 1 Congenital (n = 9) 0 5 3 1 Total (N = 31) 4 22 3 2

*QSRL indicates Q-switched ruby laser; NMRL, normal-mode ruby laser. Values are numbers of patients.

A percent decrease in the thickness of the dermal nevomelanocytic nests. Representative histologic sections of nevi with a positive treatment effect are shown in Figure 3. At first, nests appeared deeper in the nevi that did not show a histologic decrease in the dermal component, yet the difference did not reach statistical signifi- cance (P = .20). In general, a larger number of pigmented macrophages on the untreated vs treated side appeared to be associated with a positive treatment effect, yet the correlation was not statistically signifi- B cant. There were 4 nevi that had no pigmented macrophages on the untreated side; none of these nevi had a decrease in the dermal component following laser treatment. Seventeen (55%) of the treatment sites had a flat- tened rete ridge pattern, and 16 (62%) of 26 had a decrease in the junctional nevomelanocytic nests as well as a decrease in the lentiginous component. Three (50%) of the 6 nevi that had pigmented type A cells in the papillary dermis showed a decrease in these cells Figure 1. A, The center lesion is an atypical nevus before laser treatment. following laser treatment. One nevus had postinflam- B, Pigment lightening is seen on the right side of the lesion 4 weeks matory hyperpigmentation following treatment, and 2 following 1 treatment with the normal-mode ruby laser, 40 J/cm 2, 7-mm spot size. atypical nevi, 4 weeks following treatment with the NMRL, had a small focus of junctional nests that was interpreted as a benign-appearing recurrence. average total surface area of the nevi was 41 mm2. Ana- tomic locations of the nevi were 74% (n = 23) on the trunk, 16% (n = 5) on the arm, and 10% (n = 3) on the leg. None COMMENT of the patients had noted a recent change in the study moles. Table 1 describes the 4 different treatment mo- There are many different types of pigmented lesions, dalities for the 31 nevi. all of which have distinct clinical features, biological Immediately following laser treatment, 15 (48%) of behavior, time of onset, and risk for malignant trans- the study sites developed whitening or lightening of the formation. Cutaneous laser surgery has generally been pigment. The QSRL left more notable tissue whitening used for lesions with negligible concern for malig- than the NMRL. The rest of the nevi showed no signifi- nancy. Benign epidermal pigmented lesions that have cant clinical change. Sixteen (52%) of the nevi showed a been successfully treated with Q-switched lasers visible decrease in pigment on the treatment side at the include cafe´ au lait macules, lentigenes, and epheli- 4-week follow-up visit (Figure 1); 14 of these nevi had des.7,9,11 Dermal melanocytoses, such as nevi of Ota or received only 1 laser treatment. One study site in group Ito, or exogenous pigments, such as tattoos, can also 4 had a 100% clinical response to the 2 laser treatments be treated with Q-switched lasers. On the other hand, (Figure 2). Treatment responses are shown in dermal melasma, postinflammatory hyperpigmenta- Table 2 and Table 3. tion, blue nevi, and some Becker nevi and nevus spilus Pathologic examination revealed that 65% (n = 20) have not been uniformly responsive with the present- of the nevi had fibrosis as well as a mild mucinous day lasers.15,16 change in the stroma in the treatment site. For the 13 Histologically, nevomelanocytic lesions differ from nevi that had a decrease in the junctional lentiginous other types of dermal or epidermal pigmented lesions in melanocytic hyperplasia component, the number of that they contain melanocytes that form into nests. The melanocytes per basement membrane zone distance natural history and risk for malignant transformation decreased by 47% percent. For the 12 nevi with a differ depending on the type of nevus. Having an decrease in the dermal component, there was a 38% increased number of nevi is associated with an

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©1999 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/25/2021 increased risk of developing malignant melanoma,17 but ute to neoplastic changes in a nevus, yet the exact an individual benign acquired nevus is not usually wor- stimuli that trigger formation of a melanoma have not risome for malignant transformation.18 Removal of been established. Congenital nevi occur in approxi- benign nevi is often for cosmetic purposes. mately 1% of newborns. Small (Ͻ20 cm) congenital Dysplastic nevi have cellular and/or architectural nevi have a reported lifetime melanoma risk of 1% to atypia in addition to other features19 and may be asso- 2%.22 Giant (Ͼ20 cm) congenital nevi carry a 3.8% to ciated with or may be a marker for increased risk of 18% lifetime risk of developing melanoma.23-25 melanoma development.18,20,21 Though the treatment Removal of these lesions may be recommended, yet of people with dysplastic nevus syndrome is under complete or partial excisions often leave a noticeable ongoing discussion, complete surgical removal of scar, and complete removal may be impossible. atypical nevi is often recommended if the lesion is Concern has been raised that laser irradiation of moderately or severely atypical or has changed in nevomelanocytic lesions could induce a neoplastic appearance.18 Ultraviolet light exposure may contrib- change in cellular behavior, that a partially removed

A C

Figure 2. A dysplastic nevus before laser treatment (A); immediately following 1 treatment of the upper half of the nevus with the Q-switched ruby laser, 7.5 J/cm 2, 5-mm spot size (B); and 2 weeks following treatment (C). A whitening effect is seen on the treated upper half of the lesion. D, The upper half of the lesion was then treated with the normal-mode ruby laser, B D 40 J/cm 2, 7-mm spot size. The photograph shows the lesion 4 weeks following this second laser treatment. There is minimal pigment visible in the upper half of the lesion; mild hypopigmentation and textural change are present.

Table 2. Response of Nevi to Laser Treatment, Analyzed by Type of Nevus

No. (%) of Patients*

Histologic Decrease Histologic Decrease Histologic Decrease Clinical Decrease in Dermal Reparative in Pigmented in Junctional Melanocyte in Dermal Melanocyte Type of Nevus Nevus Pigment Changes Present† Macrophages Component Component Benign acquired (n = 10) 4 (40) 6 (60) 4 (50) 4 (44) 5 (71) Atypical (n = 12) 5 (42) 9 (79) 8 (67) 7 (58) 2 (33) Congenital (n = 9) 7 (78) 8 (89) 5 (55) 2 (25) 5 (55) Total (N = 31) 16 (52) 23 (74) 17 (55) 13 (45) 12 (54)

*Percentages are based on the number of nevi in each category that had the histologic characteristic being evaluated; some nevi did not have junctional or dermal components and therefore were not included. †Mucin deposition and fibrosis.

Table 3. Response of Nevi to Laser Treatment, Analyzed by Type of Laser Treatment

No. (%) of Patients

Clinical Decrease in Dermal Reparative Histologic Decrease in Histologic Decrease in Histologic Decrease in Treatment Group* Nevus Pigment Changes Present† Pigmented Macrophages Junctional Component Dermal Component 1 [QSRL] (n = 4) 4 (100) 2 (50) 3 (75) 2 (50) 1 (50) 2 [NMRL] (n = 22) 7 (32) 16 (73) 9 (41) 10 (48)‡ 7 (24)§ 3 [QSRL + NMRL; 3 (100) 3 (100) 3 (100) 0 (0) 3 (100) same session] (n = 3) 4 [QSRL, then NMRL; 2 (100) 2 (100) 2 (100) 1 (100) 1 (100) 2-wk interval] (n = 2) Total (N = 31) 16 (52) 23 (74) 17 (55) 13 (45) 12 (54)

*QSRL indicates Q-switched ruby laser; NMRL, normal-mode ruby laser. †Mucin deposition and fibrosis. ‡Measured with digital imaging system (PϽ.005). §Measured with digital imaging system (PϽ.01).

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B D

Figure 3. A, Untreated half of a dysplastic nevus, showing lentiginous melanocytic hyperplasia, several junctional nests, and perirete concentric eosinophilic fibrosis. B, Treated half of the lesion 4 weeks after treatment with the normal mode ruby laser, showing flattening of rete, papillary dermal mucinous amphophilic fibrosis, and reduced but residual lentiginous and nested melanocytic hyperplasia (hematoxylin-eosin, original magnification ϫ20). C, Untreated half of a compound nevus, showing lentiginous melanocytic hyperplasia, junctional nests, and intradermal nests stained for tyrosinase-related protein-1 (Mel-5) and unstained deep intradermal nests. D, Treated half of the compound nevus 4 weeks after treatment with the normal-mode ruby laser, showing marked reduction but not ablation of the lentiginous and nested melanocytic hyperplasia and the intradermal nests of melanocytes with tyrosinase-related protein-1 (Mel-5) (immuno-avidin-biotin–alkaline phosphatase with new fuchsin substrate [see the “Patients and Methods” section], original magnification ϫ20).

lesion would repigment in a clinically and histologically (QSRL, Q-switched neodymium:YAG [QSYAG] laser, atypical manner, or that laser removal does not permit a Q-switched alexandrite laser, and the short pulsed-dye histologic specimen to be evaluated, which is not laser at 510 nm) either alone or sequentially. For the appropriate for lesions of equivocal clinical appearance. congenital nevi, 4 of 10 patients achieved at least a 50% Some researchers have hypothesized that a partially reduction in the pigmentation of the lesion. Of 23 removed lesion is lighter and therefore has lost some of benign acquired nevi, 9 showed 25% to 50% reduction its natural protection from ultraviolet light exposure.26 in pigment and 8 had no response to the treatment. The An increased incidence of squamous cell carcinoma in short pulsed-dye laser was ineffective, and there was no burn scars has been reported,27,28 and nonlethal heating difference in treatment efficacy among the Q-switched of a cell may induce the production of stress proteins.29 lasers. The concept of debulking part of a congenital nevus in Treatment of congenital nevi has been attempted with an attempt to decrease the risk that the lesion will both QSRLs and NMRLs. Waldorf et al6 treated 18 small develop melanoma is controversial. A partially treated to medium congenital nevi with the QSRL. There was a lesion may be more difficult to monitor for neoplastic 76% lightening after 8 treatments. Five patients had more changes, and the effect on melanocytes of sublethal irra- than 90% clearing after 13 sessions. After discontinua- diation exposure is unknown. To date, there has been tion of therapy for an average of 4.9 months, 11 of 12 no direct correlation between laser treatment and patients had partial repigmentation. Grevelink et al5 malignant transformation of a dysplastic nevus follow- treated defined segments of 5 congenital nevi with both ing treatment with a laser. However, lentigo maligna the QSRL and the QSYAG laser (1064 nm). There was treated with a ruby laser recurred, and a lentigo maligna partial lightening in all lesions. The maximum depth of melanoma arose in a lentigo maligna treated with a destruction was 0.20 mm for the QSRL and 0.40 mm for laser.30 It is unclear whether this change was directly the QSYAG laser. Normal-mode ruby laser treatment has related to the laser treatment. been demonstrated, in case reports, to successfully lighten Besides surgical excision, other treatment modali- congenital nevi.13 ties for nevi, such as cryotherapy, dermabrasion, elec- In one study, benign acquired nevi treated with a trosurgery, and argon and carbon dioxide lasers, have QSRL showed a complete response in 67% of cases and been explored, yet their efficacy and clinical use are a partial response in 33% of cases.32 The depth of QSRL limited. In a preliminary study of a series of QSRL treat- destruction was 0.10 to 0.40 mm from the granular cell ments of benign nevi, 5 of 8 nevi showed a mild layer. The QSYAG and Q-switched alexandrite (755 nm) decrease in the density of nevus cells.26 For the 2 con- lasers have also been demonstrated to lighten benign genital nevi treated, there was no decrease in nevus melanocytic nevi.10 cells following treatment. The results of this study are consistent with the find- Goldman et al31 studied treatment of congenital ings of previous studies of laser treatment of nevi. Fifty- and benign acquired nevi with 4 different types of lasers two percent of the nevi (16/31) showed lightening of

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©1999 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/25/2021 pigmentation. Lack of a clinical or histologic response Accepted for publication July 13, 1998. may be due to a low pigment concentration in the lesion Presented as an abstract at the 18th annual meeting or the need for a series of treatments. Because of their of the American Society for Laser Medicine and Surgery, 694-nm wavelength, both the QSRL and the NMRL are San Diego, Calif, April 6, 1998. targeted at melanin, which can be in melanocytes, kera- The authors thank Rowena Bonoan for her assistance tinocytes, or macrophages. A higher concentration of pig- in editing the manuscript. ment will cause more absorption of the laser energy and Reprints: Joop M. Grevelink, MD, PhD, MGH Derma- more cellular destruction. In this study, a positive treat- tology Laser Center, POB 501, 275 Cambridge St, Boston, ment response trend was noted with the presence of more MA, 02114 (e-mail: [email protected]). pigmented macrophages in the papillary dermis. Follow- ing treatment, there tended to be fewer pigmented mac- REFERENCES rophages, as the laser may have caused fracture or dis- persion of the pigment. Raised lesions and those with a 1. Anderson RR, Margolis RJ, Watanabe S, Flotte TJ, Hruza GJ, Dover J. Selective deeper, less pigmented dermal component had less of a photothermolysis of cutaneous pigmentation by Q-switched Nd:YAG laser pulses response. at 1064, 532, and 355 nm. J Invest Dermatol. 1989;93:28-32. In theory, the longer pulse duration of NMRL 2. Anderson RR, Parrish JA. Selective photothermolysis: precise microsurgery by compared with QSRL better targets groups or nests of selective absorption of pulsed radiation. Science. 1983;220:524-527. 3. Taylor CR, Anderson RR. 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Submissions for Special Features

Critical Situations Readers are invited to submit examples of newly described disorders, the use of new diagnostic technology, dermatologic manifestations of important social disorders such as child abuse, and cases that highlight the complex nature of acute care dermatology to Anita G. Licata, MD, Division of Dermatology, UHC, 1 S Prospect St, Burlington, VT 05401-3444. When appropriate, these should be written in case presentation format with a brief discussion following. The Cutting Edge Clinicians, local and regional societies, residents, and fellows are invited to submit cases of challenges in management and therapetics to this section. Cases should follow the established pattern and be submitted double-spaced and in triplicate. Photomicrographs and illustrations must be clear and submitted as positive color transparencies (35-mm slides) or black- and-white prints. Do not submit color prints unless accompanied by original transparencies. Material should be accompanied by the required copyright transfer statement, as noted in “Instructions for Authors.” Material for this section should be submitted to George J. Hruza, MD, Cutaneous Surgery Center, 1 Barnes Hospital Plaza, Suite 16411, St Louis, MO 63110. Reprints are not available. Issues in Dermatology Issues in Dermatology solicits provocative essays relevant to all aspects of dermatology. Please submit manuscripts to the section editor, A. Bernard Ackerman, MD, 2 E 70th St, New York, NY 10021. Off-Center Fold Clinicians, local and regional societies, and residents and fellows in dermatology are invited to submit quiz cases to this section. Cases should follow the established pattern and be submitted double-spaced. Photomicrographs and illustrations must be clear and submitted as positive color transparencies. If photomicrographs are not available, the actual slide from the specimen will be acceptable. Material should be accompanied by the required copyright transfer statement, as noted in “Instructions for Authors.” Material for this section should be submitted to Lori Lowe, MD, Department of Pathology, Uni- versity of Michigan, Medical Science 1, M5242, 1301 Catherine Rd, Ann Arbor, MI 48109. Reprints are not available.

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