Expression of γ-H2AX in melanocytic lesions

gamma-H2AX is a marker of activated DNA damage and is overexpressed in many malignancies their precursor lesions. Previous studies have demonstrated the expression of gamma-H2AX in melanoma and dysplastic nevus, but its diagnostic and prognostic utility in a full range of melanocytic lesions has not been fully studied. In the Current study, we investigated gamma-H2AX expression in a total of 162 melanocytic lesions. We found that gamma-H2AX was observed at higher levels (percentage and intensity of staining) in melanoma in situ (12/13), primary cutaneous melanoma (32/33; with the exception of desitroplastic melanoma), and metastatic melanoma (58/62), which was statistically different from that in benign ncvus (7/9), dysplastic nevus (6/10), and Spitz nevus (5/9) considered together (P <.0001). Of note, desirioplastic melanoma (20/26) demonstrated weak or negative gamma-H2AX staining. The expression of did not show significant correlation with many melanoma prognostic factors, including Breslow depth, mitotic rate, and sentinel lyinph node status. Except for desmoplastic melanoma, no difference in gamma-H2AX levels was observed among various melanoma subtypes. The overexpression of gamma-H2AX in melanoma as opposed to nevus indicates its possible role in tnelanornagenesis. Based on the overlap in subscis of nevi and melanomas, tire potential clinical utility of this antibody remains uncertain until further Studies have been carried out in a larger cohort of mclanocytic lesions, including borderline cases. (C) 2008 Published by Elsevier Inc.