A 21-year-old female with a third ventricular tumor.

A 21-year-old female presented with a 2-months history of tinnitus, vertigo and nausea. On magnetic resonance imaging of the brain, she demonstrated a small contrast-enhancing mass in the posterior part of the third ventricle. Intraoperatively, the tumor showed a close relationship to the choroid plexus of the third ventricle. Histopathology revealed a benign schwannoma of World Health Organization grade I. To our knowledge, only 9 cases of intraventricular Schwann cell tumors have been published so far. Most of these tumors were benign schwannomas, except for 2 cases of malignant peripheral nerve sheath tumors. The tumor of our patient is the first reported schwannoma of the third ventricle. The origin of intraventricular Schwann cell tumors is unknown. They may arise from autonomic perivascular nerves in the choroid plexus or from ectopic neural crest-derived cells. Histologically, intraventricular schwannoma needs to be distinguished from other spindle cell tumors, in particular pilocytic astrocytoma and fibroblastic meningioma.