November 1st 2006
ABSTRACT: Melanomas usually do not arise from nevi; they are thought to result from UV radiation-induced DNA damage and genetic factors. The most important risk factors for melanoma are a personal history of atypical nevi, a family or personal history of melanoma, and large numbers of nevi. The ABCD criteria (asymmetry, border irregularity, color variegation, diameter larger than 6 mm) help identify early, thin tumors that might otherwise be confused with benign pigmented lesions. The E criterion has recently been added: an evolving lesion (one that shows any change in size, shape, symptoms, surface, or color) warrants prompt evaluation. If melanoma is suspected, total excision--rather than shave biopsy--is required. Melanomas that are detected and treated in the radial or early vertical phase have an excellent prognosis.