Intraventricular, cystic, atypical meningioma.

A 37-year-old male presented with a very rare cystic meningioma in the trigone of the left lateral ventricle. Neurological examination revealed mild conduction aphasia and right hemisensory disturbance. Computed tomography and magnetic resonance imaging showed a solid, enhancing tumor in the left trigone which had multiple cystic components located anteriorly and superiorly. The tumor was totally resected via a parietal, transventricular approach. Histological examination revealed an atypical meningioma with cellular pleomorphism and prominent nucleoli. Both the solid component and the cyst wall consisted of tumor cells.