Radiation-induced meningioma.

The long-term or delayed side effects of irradiation on neural tissue are now known to include the induction of new central nervous system neoplasms. However, during the first half of the 20th century, human neural tissue was generally considered relatively resistant to the carcinogenic and other ill effects of ionizing radiation. As a result, exposure to relatively high doses of x-rays from diagnostic examinations and therapeutic treatment was common. In the present article the authors review the literature relating to radiation-induced meningiomas (RIMs). Emphasis is placed on meningiomas resulting from childhood treatment for primary brain tumor or tinea capitis, exposure to dental x-rays, and exposure to atomic explosions in Hiroshima and Nagasaki. The incidence and natural history of RIMs following exposure to high- and low-dose radiation is presented, including latency, multiplicity, histopathological features, and recurrence rates. The authors review the typical presentation of patients with RIMs and discuss unique aspects of the surgical management of these tumors compared with sporadic meningioma, based on their clinical experience in treating these lesions.