Vulvar malignant melanoma versus vaginal malignant melanoma: distinct biology, distinct clinical behavior, and...

Malignant melanoma of the female genital tract is rare but highly aggressive. Vulvar malignant melanomas and vaginal malignant melanomas are commonly grouped as vulvovaginal malignant melanoma because of their anatomical proximity, low incidence, and limited disease-specific evidence. However, accumulating clinical, pathological, and biological observations suggest that this conventional grouping may mask important site-related heterogeneity. Vulvar malignant melanoma arises within a complex mucocutaneous transition zone and may partially overlap biologically with cutaneous melanoma, whereas vaginal malignant melanoma more consistently demonstrates features of mucosal melanoma. These distinctions influence patterns of presentation, local extension, lymphatic dissemination, therapeutic feasibility, recurrence behavior, and survival outcomes. Vaginal malignant melanoma is frequently diagnosed at a more advanced stage because of occult symptoms and challenging local control, contributing to its particularly poor prognosis. In contrast, vulvar malignant melanoma encompasses a broader biological spectrum that may require subsite-specific interpretation. Although both entities belong to the spectrum of lower female genital tract melanoma, emerging evidence indicates that they should not be treated as interchangeable diseases in either research design or clinical management. This review synthesizes current evidence regarding the overlap and divergence between vulvar and vaginal malignant melanoma and advocates for a site-a¹ware framework to guide future translational research, surgical decision-making, and systemic treatment strategies.