Nevoid Melanoma.

Abstract

Nevoid melanoma (NM) is a rare subtype of melanoma that is regarded as one of the most difficult to diagnose. It clinically and histopathologically resembles a benign nevus, often resulting in misdiagnosis and allowing the skin cancer to progress further before it is identified. Clinically, it presents as an elevated brown papillomatous polypoid lesion on the trunk, arms, or legs; while microscopically, it is defined by its relative symmetry, deep mitoses, and nevus-like melanocytes. Over recent decades, studies have been carried out for understanding NM and how it develops, progresses, and can be better identified. Technologic advancements in dermatoscopy, microscopy, and immunohistochemistry have allowed dermatologists and pathologists to have a better understanding of this variant of melanoma to permit an earlier diagnosis. Although NM is not any less aggressive or harmful than other subtypes of melanoma, delayed diagnosis of this skin cancer can be associated with adverse patient outcomes.