The Proteus syndrome: CNS manifestations.

Proteus syndrome is a complex hamartomatous disorder characterized by multiple, diverse, somatic manifestations. We present a case in which severe, evolving CNS abnormalities were also exhibited. Imaging findings at presentation included hemimegalencephaly, subependymal calcified nodules, and periventricular cysts. Subsequently, dural sinus thrombosis developed. Eight previously reported patients may also have had hemimegalencephaly. When neuroimaging studies show hemimegalencephaly in a child with pigmented skin lesions, Proteus syndrome should be considered in the differential diagnosis.