Atypical Mole Syndrome

Atypical mole syndrome, also referred to as dysplastic nevus syndrome, is an autosomal dominant hereditary condition which causes the person to have a large quantity of nevi (moles), often 100 or more. There is a propensity for these nevi to become dysplastic in these individuals. A slight majority of melanomas do not form in an existing mole, but rather create a new growth on the skin. more from Wikipedia