[Recent data on the risk of malignancy in congenital melanocytic nevi: the continuing debate on treatment].

Congenital melanocytic nevi (CMN) have traditionally been considered a risk factor for the appearance of melanoma, but the true incidence of malignancy is unknown. Although various studies have attempted to quantify it, the results are highly variable and it is difficult to decide on the best therapeutic approach to take. Consequently, for some time the management of CMN has depended more on personal experience than on clear scientific evidence. The most recent studies performed in large patient series indicate that the risk of malignancy in CMN is much lower than expected and mainly affects large lesions involving the axial midline. In addition, it appears that a number of melanomas develop on the site of partially or completely excised lesions, or even away from the CMN itself, making the appropriateness of prophylactic surgery increasingly doubtful.