Symptomatic lateral ventricular ependymal cysts: criteria for distinguishing these rare cysts from other symptomatic cysts of the ventricles: case report.

Abstract

Symptomatic lateral ventricular ependymal cysts are rare. Two previous cases of this lesion have been reported in the literature. We report a third case and provide radiological and histopathological criteria for differentiating this entity from common intracranial cysts. A 43-year-old man presented with a 6-year history of seizures and progressive right occipitoparietal headaches. Computed tomography and magnetic resonance imaging demonstrated a 4- x 3- x 3-cm nonenhancing cystic mass, expanding the trigone of the right lateral ventricle. The patient underwent a right occipital craniotomy. The cyst was opened, fluid was aspirated, the cyst wall was biopsied, and a cyst-subarachnoid communication was established. The patient did well postoperatively, with no seizures and with resolution of headaches. Lateral ventricular ependymal cysts are a rare cause of neurological symptoms, including headache and seizure. Distinctive radiographic characteristics distinguish these cysts at preoperative evaluation. Careful analysis of the histopathology and immunohistochemistry studies correctly identifies these lesions, gives insight into the natural history of ependymal cysts, and guides clinical management decisions.