The clinical spectrum and biologic behavior of melanoma are heterogeneous. Several clinical factors may include sex, location, and age. Histologic prognostic factors may include tumor type, tumor thickness, and mitotic index in relationship to the primary tumor. With respect to metastatic melanoma, the prognostic factors may include lymph node status, number of lymph nodes, and extracapsular extension. Cytogenetic and molecular determinants of progression of melanoma may aid the current prognostic factors when they are established more firmly. Current surgical treatment is determined by the clinical and histologic factors.