Moyamoya disease associated with a brain stem glioma.

An 8-year-old boy was found to have primary moyamoya disease associated with a brain stem glioma. For over 3 years the child had experienced transient ischemic attacks induced by hyperventilation. One month before referral to our hospital he had presented with progressive left facial nerve palsy. Magnetic resonance imaging showed a cystic mass in the lower pons. Angiography revealed severe bilateral stenosis of the internal carotid arteries and prominent moyamoya vessels in the basal ganglia. Partial resection of the tumor yielded a histological diagnosis of pilocytic astrocytoma. Local radiation therapy reduced the size of the tumor. Anastomosis of the superficial temporal arteries and middle cerebral arteries on both sides was then performed. After direct bypass surgery, the patient remained in a good condition for a 5-year follow-up period. Clinical investigation of the coincidence of primary moyamoya disease and brain stem glioma led the authors to conclude that these two diseases coexisted independently.