Multiple primary melanomas.

Abstract

The diagnosis of primary melanoma increases the risk of additional primary melanomas. We characterize the subgroup of patients with multiple melanomas. We reviewed the melanoma database. Sixty patients with multiple primary melanomas were identified. Twelve (20%) experienced melanomas in the same regional location, 43 (72%) in different locations, and 5 (8%) in both the same and different locations (> 2 melanomas). Eighteen (30%) were diagnosed concurrently with multiple melanomas, 38 (63%) subsequently, and 4 (7%) concurrently and subsequently (>2 melanomas). Forty-two percent of subsequent melanomas occurred within 3 years of the initial lesion diagnosis, 9 (17%) between 3 and 7 years, and 22 (42%) after more than 7 years. Subsequent melanomas were thinner in 70% of cases (P = .05). The mean age at first melanoma diagnosis was 38 and 59 years, respectively, for those with and without dysplastic nevi (P < .001). In patients with multiple melanomas, subsequent melanomas often occur in different regional locations several years after diagnosis of the initial lesion.