[Radiation-induced meningioma--a case report].

A case of meningioma following irradiation for a tumor of the third ventricle is reported. A four year old girl was admitted complaining of headache and vomiting. The pneumoventriculography revealed marked hydrocephalus and a mass lesion at the third ventricle. Under the diagnosis of a tumor of the third ventricle, ventriculo-atrial shunt and radiation therapy were performed. Totally, 4170 rad irradiation was directed from left temporal area through a single portal. Though she had no complaints for fourteen years, at the age of eighteen, she was admitted complaining of right hemiparasis and general convulsion. CT scan and left carotid angiogram revealed a left fronto-temporal tumor diagnosed as meningioma. Histological examination showed transitional type meningioma. The post-operative course was uneventful, and discharged without neurological sign except for slight right hemiparesis. A review of available literature revealed about 150 cases of post irradiated meningiomas. However, there were only 18 cases of meningiomas following irradiation for the treatment of brain tumors. These reported cases were also discussed.