Cerebellar venous angioma associated with angiographically occult brain stem vascular malformation. Report of two cases.

We studied two patients with angiographically documented cerebellar venous angioma (malformation) and angiographically occult vascular malformation of the brain stem. One patient had recurrent hemorrhage in the pontine tegmentum. The second patient had recurrent hemorrhage in the midbrain. None had hemorrhage originating from the abnormal cerebellar venous channels. The more benign nature of angiographic venous malformations is supported by the cases we are presenting, as well as from a review of the literature, which includes an autopsy study of similar cases. The management of multiple vascular brain lesions is contingent on the verification of symptomatic pathological blood vessels. It is emphasized that angiographically occult vascular malformation could possibly exist in the vicinity of angiographic venous malformation when the patient with intracerebral hemorrhage, especially in the posterior fossa, was diagnosed as having venous malformation.