Risk of cutaneous malignant melanoma in patients with nonfamilial atypicalnevi from a pigmented lesions clinic

Background: Atypical nevi (AN) are regarded as a major risk factor for occu rrence of malignant melanoma. Few studies report an increase in relative ri sk for melanoma in patients with nonfamilial AN. Objective: We measured the risk of melanoma in 195 patients with nonfamilia l AN. Methods: In a retrospective follow-up study the number of newly diagnosed m elanomas during follow-up were inventoried. Included patients were invited for skin screening and nevus count. Results: On the basis of our calculations, the relative risk for invasive m elanoma in patients with nonfamilial AN, including those patients with a hi story of melanoma, is 41. For individuals with AN without a previously diag nosed melanoma, the relative risk was 37. Multivariate analysis did not rev eal a specific risk factor for the occurrence of melanoma (including number of AN) because of small numbers. Invasive melanomas occurred in persons ha ving 1, 5, 12, and 172 AN, respectively. Conclusion: An increased risk for invasive cutaneous malignant melanoma in patients with nonfamilial AN was established.