後頭葉脳内のEpidermoid Tumorと対側内頸動脈瘤が合併した1例

Association of an Epidermoid Tumor with a Cerebral Aneurysm on the Contralateral Internal Carotid Artery

I．はじめに

　脳動脈瘤と脳腫瘍の合併例は0.3-4.0％程度の頻度で発生すると報告されているが，最近では診断技術・器具の改善，向上によってそれらが発見される割合が増加しつつある．動脈瘤に合併する脳腫瘍では脳下垂体腫瘍や髄膜腫が多い．

　今回われわれは内頸動脈瘤とepidermoid tumorが合併した症例を経験したが，これら両者の合併例は過去の文献を渉猟した限りでは，2例しか報告がなく，かつepidermoid tumorが後頭葉の脳内に存在したという稀なものであったので，文献的考察を加えて報告する．

Abstract

A 71-year-old female was evaluated for a sudden loss of consciousness. Initial computed tomography and cerebral angiography revealed a severe subarachnoid hemorrhage, a large cystic lesion in the left occipital re-gion, and an aneurysm at the bifurcation of the internal carotid and the posterior communicating artery on the right side. As the subarachnoid hemorrhage was thought to be clue to rupture of the aneurysm, we attempted to clip the aneurysmal neck at first, and 2 weeks later the cystic tumor was removed for the pur-pose of internal decompression. The extirpated speci-men proved to be an epidermoid tumor. Association of a brain tumor and an cerebral aneurysm is very rare, especially a combination of an epidermoid tumor and a cerebral aneurysm, and until now only 2 cases have been reported to the best of our knowledge. Moreover, the epidermoid tumor of our case was located in-tracerebrally. The phenomenon that the internal carotid aneurysm was on the left side and the tumor on the right side may suggest that these 2 lesions originated quite coincidentally. It is controversial to decide which lesion and when to treat first in a case of association of a tumor and an aneurysm, and we discussed as to the surgical therapy reviewing literature.