Meningioma metastatic to the lung.

Meningiomas constitute 15% to 18% of all primary intracranial and intraspinal tumors. Distant extracranial metastases are reported to occur in fewer than 1 in 1000 cases. Of 1992 primary intracranial meningiomas seen at Mayo Clinic Rochester from 1972 through 1994, we identified 3 (0.15%) with documented extracranial metastasis. A review of the literature suggests that previous craniotomy, venous sinus invasion, local recurrences, histological malignancy, and papillary morphology may be risk factors for systemic spread, as demonstrated in our cases. Although rare, metastatic meningioma should be considered in the differential diagnosis of abnormal findings on chest radiography in patients with known or suspected intracranial meningioma.