Atypical Moyamoya disease associated with brain tumor.

A 4-year-old boy with right retinal hemorrhage, mental retardation, and multiple minor anomalies was referred to our hospital. Computed tomography scanning revealed a cystic brain tumor at the vermis. Angiography showed stenosis of both internal carotid arteries at the supraclinoid portion and the Moyamoya vessels. The right ophthalmic artery was dilated as wide as the internal carotid artery. Stenosis of the basilar artery was also observed. Collateral circulation via the posterior inferior cerebellar artery and Moyamoya vessels in the area of the posterior cerebral artery was observed.