Cryptic vascular malformation of the choroid plexus.

A 45-year-old man and a 47-year-old woman with cryptic vascular malformations of the choroid plexus in the lateral ventricle are reported. Each patient had an intraventricular hematoma, located in the right trigone and in the anterior part of the left lateral ventricle, respectively. The vascular lesion of one patient was angiographically visualized as find abnormal vessels communicating with the right anterior choroidal artery; in the other, angiography did not reveal the lesion. In the former patient, histological examination of the excised specimen led to a diagnosis of arteriovenous malformation; in the latter, a diagnosis of venous malformation was made. Both patients were successfully treated surgically.