Cyst of the choroid plexus of the left lateral ventricle.

A cyst of the choroid plexus of the left ventricle is described. The cyst was lined by a choroidal epithelium and filled with cerebrospinal fluid. It produced an intermittent obstructive syndrome. The cyst was almost completely invaginated into the third ventricle, simulating an expanding process in the third ventricle. After microsurgical removal, the recovery of the patient was complete. Electronmicroscopy of the cyst wall is reported. Histological and neuroradiological features are discussed.