Anaplastic hemangiopericytoma in the frontal horn of the lateral ventricle.

Intracranial hemangiopericytomas are uncommon tumors, and their intraventricular occurrence is even rarer. We report a 40-year-old man who presented with raised intracranial pressure. His MRI showed a 3.3 × 3.2 × 3.2 cm heterogeneously enhancing lesion in the left frontal horn obstructing the foramen of Monro and causing hydrocephalus. The tumor was excised through an anterior interhemispheric, transcallosal approach, and histopathology revealed an anaplastic hemangiopericytoma (World Health Organization grade III). To our knowledge this is the first report of this rare pathology being located within the frontal horn of the lateral ventricle.