くも膜下出血（SAH）にて発症した大孔部髄膜腫の1例

Foramen Magunum Meningioma Presented as Subarachnoid Haemorrhage

Ⅰ．はじめに

　脳腫瘍が腫瘍内出血を来した場合，多くは急激な症状増悪を引き起こす．このような腫瘍内出血を来すのは悪性脳腫瘍の場合が多く，髄膜腫など良性腫瘍の場合は悪性所見の存在下，周術期，塞栓術後，放射線治療後に多く，特発性に来すことは稀とされている^1,5,8)．今回，画像的診断が困難なくも膜下出血（SAH）にて発症し，腰椎穿刺にてSAHを診断し得た特発性腫瘍内出血を伴う大孔部髄膜腫を経験したので文献的考察を加えて報告する．

　A 59-year-old woman was admitted with to our hospital with a sudden severe headache that had lasted for 5 days. Neck stiffness was present, but no other neurological deficits were present. Subarachnoid hemorrhage and intra-tumor hemorrhage were not noted on a head computed tomography（HCT). The patient's cerebrospinal fluid was xanthochromic. Magnetic resonance imaging（MRI）demonstrated a gadolinium-enhanced tumor with hemorrhagic changes around the foramen magnum. After conservative therapy, MRI showed a decrease in tumor size and a dural tail sign. This tumor was diagnosed as a hemorrhagic meningioma, and was resected with a posterior suboccipital approach. Histology confirmed that this tumor was a benign transitional meningioma with hemorrhagic change. This is a rare case involving benign meningioma onset by hemorrhagic change. Postoperative tumor recurrence was not present.