A meningioma is a tumor arising from the meninges that attaches to the dura mater of the brain or spinal cord. They are the most common intracranial tumor in adults, accounting for 34% of all primary central nervous system tumors. This dural-based tumor is twice as common in women than in men. Peak incidence is in the sixth decade of life; the tumor is uncommon in children.

Meningiomas are typically slow growing and benign, but the condition can be complicated by size and rate of growth and compression of surrounding brain tissue. In rare cases, meningiomas can become malignant. Small tumors may be asymptomatic. Large tumors may cause a variety of symptoms including headaches, focal seizures, weakness, numbness, incontinence, apathy, aphasia, anosmia, and increased intracranial pressure.  

Risk factors include hormonal factors (progesterone > estrogen > androgens), genetic syndromes such as neurofibromatosis type 2, and exposure to ionizing radiation. Prognosis is generally good, with a 5-year survival rate of 70%. Patients with a history of radiation exposure tend to have more aggressive and atypical tumors with a worse prognosis.