Epidermal nevus syndrome with azygos anterior cerebral artery.

Epidermal nevus syndrome is a neurocutaneous disorder characterized by the association of epidermal nevi with central nervous system or skeletal abnormalities. Central nervous system abnormalities include hemimegalencephaly, hydrocephalus, various migration disorders, intraspinal lipomas, and enlarged spinal roots. Rarely, vascular anomalies cause neurologic signs. We report on a 30-month-old girl with epidermal nevus syndrome who also exhibited vascular malformations of the azygos anterior cerebral artery, a cortical aneurysm, and right internal carotid artery hypoplasia. This rare vascular abnormality was not previously reported in patients with epidermal nevus syndrome.