Atypical meningioma of the sylvian fissure.

Meningiomas are meningothelial cell neoplasms that account for approximately 25% of all primary intracranial tumors. Most meningiomas are slow-growing benign lesions, and they are usually attached to the inner surface of the dura mater. Nevertheless, since the first description by of Cushing and Eisenhardt, many meningiomas without dural attachment have been reported. A subgroup located in the sylvian fissure (also called deep sylvian meningiomas) has been described, and these represent a radiological and neurosurgical challenge. We describe an atypical sylvian fissure meningioma in a 23-year-old male with a brief history of headache and mild hemiparesis. We also review the pertinent literature defining the major epidemiological, clinical, radiological and surgical characteristics of these rare tumors.