MULTIPLE PRIMARY MELANOMAS - ANALYSIS OF 49 CASES

Development of multiple primary melanomas is a rare but well recognize d disease, with an estimated incidence ranging from 1.75% to 8.5% in s everal series. The clinical, histological and epidemiological characte ristics of 49 patients, identified from 2470 with histologically confi rmed melanoma, are described in this study. Thirty-five of these patie nts had two primary melanomas, 11 had three melanomas and three had fo ur, five and six melanomas, respectively. Diagnosis was concurrent in 22 patients (45%); in the remaining cases the median time interval bet ween the first and second melanoma was 22.6 months and the longest int erval was 21.5 years. The mean Breslow's thickness decreased significa ntly (P < 0.001) from the first melanoma to the second and third lesio n. The multiple melanoma patients had a higher percentage of subjects over 70 years of age or with lentigo maligna melanoma than single mela noma patients. The mean follow-up time was 12 years (range 4-23 years) . The B-year survival rate from first melanoma excision (83%) does not differ from that of patients with a single melanoma. In conclusion, t he presence of multiple primary melanomas does not appear to be a nega tive prognostic factor; our data show the importance of close follow-u p in melanoma patients in order to detect not only metastases, but als o subsequent primaries in their earliest phases. (C) 1998 Lippincott W illiams & Wilkins.