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Cutaneous melanomas are characterized by a range of histological appearances, and several morphological variants have been described. In this study, we report a variant of superficial spreading melanoma that is characterized by large, irregular junctional melanocytic nests. The junctional nests varied in shape and size, showed focal tendency to confluence, and were often surrounded by a cuff of epidermal keratinocytes. The melanocytes comprising the nests showed variable cytological atypia. In most of the cases, scant intraepidermal or junctional single melanocytes were seen, and other well-documented diagnostic criteria for melanoma were lacking, and as a result, histological recognition of these tumors as melanoma was difficult. Some cases were associated with an invasive dermal component or showed evidence of sun damage. To provide supporting evidence for malignancy, we analyzed these tumors for genomic aberrations. Using array comparative genomic hybridization (aCGH), we identified multiple genomic aberrations in all analyzed cases. A similar pattern of genomic aberrations was seen in a control group of bona fide superficial spreading melanomas, suggesting that these 'melanomas composed exclusively or predominantly of large nests' are indeed variants of superficial spreading melanoma. Fluorescence in-situ hybridization (FISH) was positive in 40% of the cases. However, using aCGH, the FISH-negative cases showed multiple genomic aberrations in regions that are not covered by FISH. The low sensitivity of the FISH test can be explained by the fact that FISH only evaluates four genomic loci for aberrations, whereas aCGH surveys the entire genome. In summary, we present histological and molecular genetic evidence for a morphological variant of superficial spreading melanoma. Awareness of the histological features will aid in their correct diagnosis as melanoma, and in difficult cases, judicious application of ancillary tests such as aCGH (rather than FISH) will assist accurate diagnosis.

Background: Clinical information on histologic referral sheets is usually very limited, and particularly for inflammatory skin disorders, dermatopathologists often ask referring physicians for clinical correlation., Objective: In this study we tested the value of clinicopathologic correlation in the histopathologic diagnosis of inflammatory skin disorders., Methods: One-hundred biopsy specimens were digitalized and stored on 3 DVDs along with the clinical images. All cases were evaluated by 9 independent full-time dermatopathologists, initially without looking at the clinical pictures and subsequently after checking them. All diagnoses were finally compared with the "reference" diagnosis established in Graz, Austria, and the results were statistically analyzed., Results: After evaluation of the clinical images, the number of dermatopathologists making a correct diagnosis was increased in 70 cases, unchanged in 25 cases, and decreased in 5 cases. The total number of correct diagnoses increased from 332 (diagnoses before evaluation of clinical pictures) to 481 (diagnoses after evaluation of clinical pictures), with a 16.6% increase in the total., Limitations: The computerized setting is different from real-life dermatopathology and physical examination of patients., Conclusion: Our study clearly shows that clinical pictures should be added to biopsy request slips of inflammatory skin disorders whenever possible, as they allow a better interpretation of histopathologic findings., (Copyright © 2009 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.)