Giant pigmented nevi: clinical, histopathologic, and therapeutic considerations.

Eighty pediatric patients with giant pigmented nevi more than 20 cm in their greatest diameter are reported. The incidence was 1 in 4150 general pediatric outpatients. The mode of inheritance of giant pigmented nevi is probably multifactorial; four second-degree relatives of our patients also had large nevi, and there was a 2:1 female predominance. Satellite nevi were present in 74% and nevi in mucous membranes in 31% of the patients. Eighty-six percent of nevi were pigmented and hairy. Benign nodules were observed in 19% of the patients and plexiform overgrowths in 6%. Nevi extensively involving the extremities resulted in reduced growth of the affected limb. Electroencephalograms showed abnormalities in 20% of the patients with giant pigmented nevi involving the head and upper portion of the trunk. Malignant transformation appeared in four patients and was fatal in three of them. Management consisted of observation only in 49%, surgery in 27.5%, chemical peel in 21%, and dermabrasion in 2.5% of the patients. The mean follow-up was 4.7 years.