An update on cutaneous melanocytic lesions

Significant advances in our understanding of melanocytic neoplasms at the genomic level have occurred in the last decade. This includes identifying initiating genomic events which correlate highly to morphology for benign intermediate and malignant melanocytic neoplasms. Among spitzoid melanocytic neoplasms, mRNA sequencing has revealed specific genomic fusions correlating to morphologic features. Additionally a number of biomarkers for intermediate and malignant grade lesions have been identified. This includes molecular studies looking for copy number aberrations or specific mutations in spitzoid neoplasms, deep penetrating nevi, and blue nevi. mRNA expression profiling has become an important test for prognostication of melanoma. In this review, we provide an overview of the molecular landscape and summarize the histomorphology of a subset of melanocytic neoplasms, including blue nevi, deep penetrating nevi, pigmented epithelioid melanocytomas, Spitz nevi, and BAPomas. We further discuss novel biomarkers for prognostication and the recent updates to melanoma staging.