Giant congenital nevus

Abstract

A 17-year-old boy presented with painful swelling of the front of his chest after a roadside brawl. He had been born with a birthmark on his chest that had grown steadily to its present size. We noted a giant (32-by-21-cm), circular, well-defined, spongy, hairy, jet-black congenital melanocytic nevus occupying the lower chest and epigastrium (Panel A). The nevus was warm to the touch and mildly tender. Multiple satellite lesions over the trunk, face, limbs, palms, and lower back (Panel B, arrow) were present. No neurologic deficits were identified. Congenital nevi, which are benign proliferations of melanocytes in the dermis, epidermis, or both, occur in 1 to 2% of newborn infants. If the nevus is greater than 20 cm in diameter, it is classified as giant. Satellite lesions are often found in patients with giant congenital nevi. Giant congenital nevi may cause cosmetic problems, undergo malignant transformation, or be a part of the rare syndrome of neurocutaneous melanosis, which is characterized by congenital melanocytic nevi and melanotic neoplasms of the central nervous system. The patient's symptoms improved with oral antibiotic therapy. Despite discussion of the risk of subsequent melanoma, the patient and his parents declined surgical resection of the giant nevus.