Asymptomatic cerebellar venous angioma.

In contrast to the scarcity of recorded cases of radiologically studied venous angiomas, venous angiomas are the most common of the four basic types of congenital intracranial vascular malformations encountered incidentally at autopsy. Their clinical significance remains unclear. When symptomatic, they are associated mainly with hemorrhage or mechanical pressure on cranial nerves by anomalously enlarged veins, however, it is, as yet, impossible to predict what course an asymptomatic cerebellar venous angioma will take. The risks of surgery appear to exceed those of the natural history of the disorder. The following two cases of asymptomatic cerebellar venous angioma are recorded because of the rarity of the condition's diagnosis and the possibility of controversy in its conservative management.