診断に苦慮した微小脳髄膜瘤による髄液耳漏の1例

A Case of Spontaneous CSF Leak Caused by Meningoencephalic Herniation

　はじめに

　髄液耳漏は一般的には外傷や中耳手術の際の硬膜損傷，感染（慢性中耳炎など），新生物が原因で二次的に発生する。しかし，原因がはっきりしないこともあり，その場合は特発性髄液耳漏と診断されている。

　今回われわれは，外傷や中耳炎の既往がなく約2年間滲出性中耳炎の緩解と増悪を繰り返し，精査の結果，中耳滲出液のRI，β2トランスフェリン検出により髄液耳漏と診断し，手術により微小脳髄膜瘤が原因であった症例を経験したので，若干の文献的考察を加え報告する。

A 70-year-old man was suffered from recurrent serous otitis media for 2 years. There was no history of head trauma, infection, or ear surgery. AlthoughCT scan demonstrated no distinct tegmen defect, glucose of the middle ear fluid was positive, suggest-ing cerebrospinal fluid. After confirmation of CSF in the middle ear fluid by beta-2 transferrin, middle cranial fossa craniotomy was performed for the treatment of CSF leak. Two small pieces of granula-tion like tissue originated from brain penetrated the roof of tympanic cavity. The tissue was confirmed as brain tissue histologically. The fistula was closed by a temporal fascia graft with preservation of hearing.