Meningiomas of the pineal region and third ventricle.

The clinical presentation, radiological findings, and surgical management of two cases of meningioma arising from the velum interpositum without dural attachment are described. The true nature of these tumors was not suspected despite extensive preoperative diagnostic evaluation. A total removal was effected in both cases with the use of the operating microscope and a posterior fossa approach to the pineal region. A review of similar cases from the English literature is presented.