Use of Fluorescence In Situ Hybridization for Diagnosis of Rare Nevoid Melanoma: A Case Report

Abstract Nevoid melanoma is rare variant of conventional melanoma that looks deceptively benign and can be challenging to differentiate from the common nevus. Histopathologic examination of nevoid melanoma may closely resemble benign nevi. Nevoid melanoma frequently has a deceptively bland nevus-like histological appearance. It is only at intermediate and high power magnification that suspicion for melanoma arises based on its subtle histological features. Small and intermediate cell types are sometimes called ‘‘minimal deviation melanoma’’ or ‘‘Lawyer's melanoma’’ due to them being a classic diagnostic trap and common diagnosis after metastasis. Genomic techniques, including comparative genomic hybridization (CGH) and fluorescence in situ hybridization (FISH), can be useful to identify cytogenic abnormalities leading to diagnosis of melanoma. We aim to raise awareness for and strengthen recognition of an overlooked metastatic skin lesion.