Abstract
Melanoma comprises a heterogeneous group of malignancies arising from melanocytes in cutaneous, acral, mucosal, and ocular sites, each exhibiting distinct clinical behavior, histopathologic features, molecular profiles, and prognostic implications. Contemporary classification systems, including the World Health Organization framework, increasingly emphasize tumor evolutionary pathways and cumulative solar damage (CSD) status to better reflect biologic diversity and guide management. This review provides a comprehensive overview of the major melanoma types and subtypes, including ocular, mucosal, acral, and cutaneous melanoma, as well as clinically important variants such as amelanotic melanoma. For each entity, we summarize epidemiology, risk factors, clinical presentation, dermoscopic findings, histopathologic characteristics, and patterns of disease progression. Particular attention is given to diagnostically challenging subtypes—such as acral lentiginous, desmoplastic, nevoid, and spitzoid melanomas—and to the role of dermoscopy and molecular testing in improving diagnostic accuracy. An enhanced understanding of melanoma subtypes and their biologic behavior is essential for timely diagnosis, appropriate staging, individualized treatment planning, and improved patient outcomes.