14年の経過で増大し症候性となった後部側頭葉底面くも膜囊胞の1手術例

A Case of Symptomatic Arachnoid Cyst,that had been Growing for 14 Years,at the Posterior Part of the Left Temporal Lobe

Ⅰ．はじめに

　Computed tomography（CT）およびmagnetic resonance image（MRI）の普及に伴い，くも膜囊胞を発見する機会が増えているが，症候性の病変の頻度ははっきりとしない．症候性となるものは，小児や若年者に多いと言われるが，成人および高齢者の報告も散見される．われわれは14年の経過で増大し，症候性となった後部側頭葉底面くも膜囊胞の1例を経験した．術中所見および諸検査所見よりその増大機序について検討したので，文献的考察を加え報告する．

　The authors report a 54-year-old woman with headache in whom a cyst was detected at the posterior part of the left temporal lobe following a traffic accident in 1993. Symptoms had recently worsened and computed tomography demonstrated an enlarged cyst in 2007. Thereafter, the patient underwent cyst fenestration. Intraoperative findings showed multilocular cysts with calcification. Symptoms improved immediately. Histological findings showed that the cyst was composed of collagenous membrane and a monolayer of cells compatible with arachnoid cyst. These findings also showed calcification and we considered that growth of the arachnoid cyst had been induced by trauma.

　We expected an arachnoid cyst with a single cavity, but this lesion was multilocular. Retrospectively, cine magnetic resonance image (MRI) seemed to show multilocular cysts. Cine MRI might be an effective tool to determine whether a cyst is multilocular.