Changes in clinical presentation and management of malignant melanoma.

Records of 147 patients with primary cutaneous malignant melanoma treated at the Lahey Clinic from 1955--1979 were reviewed. Complete clinical follow-up data were obtained, and all pathologic material was reviewed. Proposed new risk categories based on a modification of the Clark and Breslow categorizations are outlined. The incidence of low-risk melanoma has dramatically increased (from 23--53%) and that of high-risk melanoma has decreased (from 34--10%) over the period of this study. Dermal punch biopsy gives accurate staging information and carries no increased risk of local recurrence, nodal metastases, or death from disease. Resection of a margin of clinically uninvolved skin measuring twice the diameter of the primary melanoma minimizes local recurrence (2.5% or less), does not adversely affect survival, and reduces the need for skin grafting. Arbitrary wide margins are not justified. Regional lymphadenectomy offers no improvement in survival in patients with low-risk and moderate-risk melanoma and can play only a minor role at most in improving survival for patients with high-risk melanoma.