Congenital melanocytic nevi is present in approximately 1% of new born. The lesions classified as small and medium are relatively common, while giant pigmented nevus, measuring over 20cm in the largest diameter, is a rarer condition, the incidence of which is estimated to be one in every 20 thousand births. The small and medium congenital melanocytic lesions present a low risk of malignant degeneration and this rarely occurs in childhood. On the other hand, there is a risk estimated between 5 to 12% of a melanoma growing from or being related to a giant nevus, furthermore in half of the cases this occurs before three years of age. Besides the possibility of malignant degeneration, the neurological involvement and psychological implications arising from aesthetic aspect are two important factors related to the giant lesions and also influence the therapeutic approach.
melanoma; nevus, pigmented
