Cerebriform Nevus Sebaceous
A 12-year-old girl presented with a tan plaque measuring 7.0 cm×4.0 cm on her scalp. The lesion had been present since birth and had gradually increased in size, with a cerebriform appearance (Panel A). Physical examination, neurologic examination, and radiography of the skull were unremarkable. Histologic findings showed papillomatous epidermal hyperplasia and large numbers of mature sebaceous glands with no evidence of cancer (Panel B). A diagnosis of cerebriform nevus sebaceous was made. Nevus sebaceous is a congenital sebaceous hamartoma that is thought to be caused by mosaic genetic mutations in the HRAS and KRAS genes. When nevus sebaceous is extensive, it may be part of a complex syndrome that includes skeletal, ocular, and neurologic abnormalities. Because of the risk of malignant transformation, complete excision before puberty is often recommended. Cerebriform nevus sebaceous is a rare variant of nevus sebaceous. In this case, the patient underwent complete excision and skin grafting, with no signs of recurrence at follow-up 10 months later.
