Many Faces of Melanoma: A Comparison Between Cutaneous, Mucosal, Acral, Nail, and Ocular Malignancy

A melanoma is a malignant neoplasm that originates from melanocytes. Melanocytes are found in various body sites—they are most commonly found in the skin (including acral sites and nail units), ocular structures, and mucosal membranes. This narrative review aims to comprehensively summarize the current information available regarding several types of melanomas and to analyze the existing evidence. Despite the same origin—melanocytes—melanomas appear to be a heterogeneous neoplasm. A thorough analysis of several types of melanomas reveals differing genetics, risk factors, epidemiology, and prognosis. The most common locations for melanomas are primarily the skin, followed by ocular structures and acral sites. Mucosal melanomas occur more frequently in older individuals than cutaneous melanomas; cutaneous melanomas occur more frequently in males. Mucosal and nail unit melanomas predominantly affect females, whereas ocular melanomas occur with similar frequencies in both sexes or are slightly more common in males. The highest incidence of amelanotic cases is observed in patients with mucosal, uveal, and conjunctival melanomas. Mucosal melanomas, including conjunctival, present as multifocal lesions more often than in other affected body areas. Additionally, the poorest survival rate is observed for mucosal melanomas.