脳血管撮影検査後に腫瘍内出血を来した放射線誘発性髄膜腫の1例

Exacerbation of Radiation Induced Meningioma due to Hemorrhage after Cerebral Angiography: A Case Report

Ⅰ．はじめに

　髄膜腫には異型髄膜腫，退形成性髄膜腫など悪性の経過を辿るものが含まれるが，基本的には良性腫瘍であり腫瘍内出血性などで急性増悪することは比較的稀と考えられている．だが少ない頻度ではあるが，出血で発症する場合^1,13,27)や術前の塞栓術後に出血性変化を来した報告^{3,14,15,22,28)}が散見される．

　今回われわれは，放射線誘発性と考えられる髄膜腫が，脳血管造影検査後に腫瘍内出血を来し急性増悪した稀な症例を経験した．文献考察を加え報告する．

　We report the case of a 34-year-old woman who exhibited acute deterioration in her condition after cerebral angiography for evaluation of a large meningioma. She had undergone surgery and irradiation for a glioma in the right occipital lobe 23 years before this episode. She experienced incapacity at work. On CT and MRI, a large meningioma was detected on the left frontal convexity; this tumor was thought to be radiation-induced. Cerebral angiography was performed to assess the vascularization of the tumor. Her condition began to deteriorate 2.5 h after the cerebral angiography. CT revealed an increase in the mass of the tumor, and a high density area in the tumor. We immediately removed the tumor. Histopathological examination revealed the tumor to be a meningothelial meningioma. New hemorrhagic foci were identified in the tumor. In addition, macrophages containing hemosiderin were detected, and some of the tumor vessels exhibited hyaline degeneration. We suspected that angiography triggered bleeding in the meningioma, which was already predisposed to hemorrhage.