動眼神経麻痺と三叉神経痛を来したメッケル腔類皮囊胞の1例

Dermoid Cyst in Meckel's Cave Presenting with Oculomotor Nerve Palsy and Trigeminal Neuralgia:A Case Report

Ⅰ．はじめに

　頭蓋内類皮囊胞は胎生期遺残組織から発生する囊胞性腫瘍で，全脳腫瘍の0.2%と稀な腫瘍である^2）．また，その発生部位は下垂体周辺部，脳幹周囲，小脳正中部などの頭蓋内正中線上に好発するとされており，メッケル腔に発生するものは極めて稀である^7）．今回われわれは，メッケル腔に発生して動眼神経麻痺と三叉神経痛を来した類皮囊胞の1例を経験したので，文献的考察を加えて報告する．

　The authors report a rare case of an intracranial dermoid cyst found in Meckel's cave. A 63-year-old woman developed left oculomotor nerve palsy and was referred to their hospital. Magnetic resonance imaging revealed a cystic lesion in the left Meckel's cave and prepontine cistern, but her symptoms gradually improved during conservative observation. However, three years later she complained of left facial pain in the territory of the second branch of the trigeminal nerve. The left oculomotor nerve palsy exacerbated again. Although her trigeminal neuralgia improved after carbamazepine administration, her oculomotor nerve palsy did not recover. Therefore, she underwent direct surgery through the anterior transpetrosal approach, and the fat-containing tumor cyst was completely resected. The tumor was strongly compressing the left trigeminal nerve and its ganglion in Meckel's cave. After surgery, her facial pain completely resolved and her oculomotor nerve palsy gradually improved. Histological examination revealed that the cyst wall was composed of a single layer of squamous epithelium and contained hair and keratin. A pathological diagnosis of a dermoid cyst was made.