What genomics has taught me about melanocytic neoplasms

Recent advances in the molecular biology of melanocytic neoplasms have enabled what were previously investigational tools to be used for more accurate diagnosis of melanocytic neoplasms. These include fluorescence in situ hybridization, comparative genomic hybridization, and sequencing. Correlation with conventional histopathology and immunohistochemistry has led to a better understanding of the classification of melanocytic neoplasms, as well as to the identification of new clinicopathologic entities. Herein are illustrated some pitfalls in the diagnosis of melanoma, as well as variants of Spitz's nevus that correlate with specific genomic aberrations such as gains of chromosome 11p and loss of the BAP-1 gene on chromosome 3p.