 Experts, such as the American Academy of Dermatology, say that the vast majority of moles are benign.Nonetheless, the U.S. National Cancer Institute estimated that 62,480 new cases of melanoma and 8,420 related deaths would appear in the United States in the year 2008.Data on the chances of transformation from melanocytic nevus to melanoma is controversial, but it appears that about 10% of malignant melanomas have a precursor lesion, of which about 10% are melanocytic nevi.