Multicentric malignant melanoma in a giant melanocytic congenital nevus 20 years after dermabrasion in adulthood

BACKGROUND. Dermabrasion is one approach to the treatment of treating giant melanocytic congenital nevi. Treatment is recommended to reduce the risk of spontaneous malignant transformation of giant nevi into malignant melanomas that usually occur in childhood. OBJECTIVE. To describe the development of a multicentric malignant melanoma in a giant melanocytic congenital nevus after dermabrasion. METHODS. We report about a 46-year-old male patient who developed a multicentric malignant melanoma in a giant melanocytic congenital nevus. The nevus was located on his left shoulder extending to his neck and chest. Previously, dermabrasion of the nevus was performed twice at the ages of 26 and 28. RESULTS. To our knowledge, this is the first report of malignant transformation of a giant nevus into a multicentric malignant melanoma diagnosed 20 years after the procedure of dermabrasion. CONCLUSION. We conclude that a close follow-up of such patients is mandatory.