RISK OF MELANOMA IN MEDIUM-SIZED CONGENITAL MELANOCYTIC NEVI - A FOLLOW-UP-STUDY

Background: The risk of the occurrence of malignant melanoma (MM) in m edium-sized (1.5 to 19.9 cm in diameter) congenital melanocytic nevi ( CMN) is the subject of controversy. Universally accepted recommendatio ns regarding the management of such lesions have not been made. Object ive: Our purpose was to assess the risk of MM arising in medium-sized CMN. Methods: The study included 230 medium-sized CMN in 227 patients, first seen in a private dermatology practice from 1955 to 1996, who w ere followed up for MM arising within their CMNs. Criteria for entry i nto the study included (1) a clinically diagnosed medium-sized CMN, (2 ) minimum follow-up period of 1 year, and (3) a photograph of the lesi on in the patient's medical record. Results: No MM occurred in a mediu m-sized CMN during an average follow-up of 6.7 years (median, 5.8 year s) to an average age of 25.5 years (median, 19.1 years). Conclusion: T he results of this short-term follow-up study do not support the view that there is a clinically significantly increased risk for MM arising in banal-appearing medium-sized CMN or that prophylactic excision of all such lesions is mandatory. Life-long medical observation seems a r easonable alternative for many medium-sized CMN.