Meningiomas originate in arachnoid coverings of brain; 90% intracranial, 10% spinal.

Comprise 20% of all intracranial tumors. M:F ratio 1:2. Peak age: 50 to 70 years. Rare tumor in children, frequently associated with neurofibromatosis type 2.

Multiple meningiomas (typical of neurofibromatosis): 5% to 15% of patients.

Radiotherapy is only established risk factor. Estrogen, viral antigens, loss of tumor suppressor gene may contribute.

Cells arranged in sheaths separated by connective tissue trabeculae. Whorls of arachnoid cells surround central hyaline material (psammoma bodies). Calcification frequent.

Malignant meningiomas rare but aggressive; may metastasize outside central nervous system.

Risk of recurrence depends on tumor grade: benign (7% to 20%), atypical (30% to 40%), anaplastic (50% to 78%).

Dictated by tumor location: seizures, hemiparesis, gait disturbance (convexity, falx); diplopia, visual loss, cranial neuropathies (skull base). Often asymptomatic.