Common lesion found in about 1 % of newborns which measures 20 cm or more in its largest diameter. It often covers a large portion of the body surface as the back, buttocks or an extremity. Giant melanocytic nevi are unevenly pigmented. Most of them display large, coarse terminal hairs (bathing trunk or giant hairy nevi). If situated on the head or neck, such nevi may be associated with leptomeningeal melanoctytosis, the disorder being called neurocutaneous melanosis. Giant nevi situated in the lumbosacral area may be associated with meningomyelocele or spina bifida. These nevi show a potential for develpment of malignant melanoma, the lifetime risk of malignant change being about 6 % according to the estimations of Rhodes et al.
Giant Melanocytic Nevus, Nevus Giganteus