くも膜下出血で発症した膠芽腫の1例

Intracranial Malignant Glioma Presenting as Subarachnoid Hemorrhage

Ⅰ．はじめに

　くも膜下出血症例のうち，15～24%において血管撮影上異常所見が認められず，その中で稀に脳腫瘍が出血源になると報告されている^9,16)．われわれが渉猟し得た限りでは，くも膜下出血で発症した神経膠腫の報告は，これまでに計9例が報告されている^{3,6,7,10,13,18)}．なかでも膠芽腫の報告は本例を含めて3例のみであり，稀な病態といえる．今回，くも膜下出血で発症し，診断に頭部MRIが有用であった膠芽腫症例を経験したので，文献的考察を加えて報告する．

　Cerebral aneurysms are the predominant cause of spontaneous subarachnoid hemorrhage（SAH). However, if an aneurismal cause has been excluded, there remains but a short list of meningiomas or metastatic lesions as possible causes. This article details a case of neoplasm that presented exclusively with SAH. A 31-year-old male presented with a SAH with normal cerebral angiography. The initial magnetic resonance image（MRI）revealed a lesion in the left uncus thought to be recovering hemorrhage. Subsequent MRI, however revealed the mass to be expanding. A neuroendoscopical biopsy of the lesion established a diagnosis of glioblastoma. An affirmation is made that patients experiencing “angiographically-negative” SAH should undergo MRI, occasionally on a serial basis, to exclude other etiologies for hemorrhage, including neoplasma.