神経線維腫症1型に合併し，側脳室内に伸展したgangliogliomaの1例

A Case of Ganglioglioma Extended to the Lateral Ventricle and Associated with Neurofibromatosis Type 1

Ⅰ．はじめに

　神経線維腫症1型（neurofibromatosis type 1：NF-1）は，常染色体優性遺伝を示す遺伝性疾患であるが，その半数は遺伝歴のない孤発例で，神経系の合併病変として神経線維腫，神経膠腫，悪性末梢神経鞘腫などが知られている．神経膠腫の大半は視神経膠腫で，その他，びまん性星細胞腫，膠芽腫があり，稀に上衣腫，多形黄色星細胞腫（Pleomorphic xanthoastrocytoma：PXA），髄芽腫，胚芽異形成神経上皮腫瘍（Dysembryoplastic neuroepithelial tumor：DNT），gangliogliomaなどが報告されている．Gangliogliomaでは，大脳半球，脳幹，視交叉，視神経，脊髄などの病変が報告されているが脳室内の症例は未だ見当たらない．今回，われわれは，神経系の合併腫瘍として尾状核頭部に発生し側脳室前角に進展したgangliogliomaの稀な1例を経験した．症例を呈示し，稀な合併腫瘍について考察する．

　We encountered a rare case of intraventricular ganglioglioma associated with neurofibromatosis type 1. A 42-year-old woman presented with a feeling of heaviness of the head and dizziness. She was diagnosed with neurofibromatosis type 1 because she had multiple subcutaneous neurofibromas and café au lait spots. On admission, she deteriorated slightly（Japan Coma Scale 1）and suffered from cognitive dysfunction and right hemiparesis. A computed tomography（CT）scan showed that she had an obstructed hydrocephalus with a long and circular mass lesion, 2cm in diameter, in the anterior horn of the left lateral ventricle. The mass showed low signal intensity（SI）on the T1-weighted image（WI), heterogeneous high SI on the T2-WI, and dense enhancement on a Gd-DTPA contrast MRI, extending from the head of the left caudate nucleus to the lateral ventricle. The patient underwent an urgent operation via an anterior transcallosal approach because of an obstructed hydrocephalus. The tumor was removed in its entirety, including its origin at the caudate head. The pathological diagnosis was a ganglioglioma grade 1 according with the classification of the World Health Organization. Here we describe this case and discuss the rare association between gangliogliomas and neurofibromatosis type 1.