Clinical and Histologic Features of Multiple Primary Melanoma in a Series of 31 Patients

We reviewed all cases of multiple primary melanoma diagnosed at our department over a 32-year period (1987-2019) to better characterize this subgroup of patients and develop a tailored protocol to offer them closer follow-up.

Retrospective, observational, descriptive study of patients diagnosed with multiple primary melanoma at a tertiary care hospital between January 1987 and March 2019. We collected clinical, epidemiologic, and histologic characteristics of primary and subsequent melanomas and performed a descriptive analysis.

Thirty-one patients (15 men and 16 women) with a median age of 67years (range, 36-85years) were included. Second primary melanomas were diagnosed after a median of 2years (range, 0-4years). The median number of melanomas per patient was 2 (range, 2-6). Twenty-three of the 31 patients, 25 had 2 primary melanomas (80%), 4 had 3 melanomas (13%), and 2 patients each had 5 and 6 primary melanomas. Subsequent melanomas were less invasive than the initial primary melanomas. Median Breslow thickness was 1mm (range, 0.67-4mm) for the first primary melanoma and 0.5mm (range, 0.32-2.42mm) for subsequent melanomas.

Subsequent melanomas are thinner than primary melanomas. We observed an increase in the number of cases of multiple primary melanoma diagnosed in the last 2years of our study. Our findings highlight the importance of close, long-term follow-up of patients.