視床と傍側脳室に多中心性病変をもったgerminomaの1例

A Case Report of Germinoma with Synchronous Lesions in the Thalamus and Para Lateral Ventricle

Ⅰ．は じ め に

　Germinomaは早期に正確な診断がつけば，化学療法と放射線療法で根治しうる疾患群である⁵⁾．診断に関しては，最近では開頭術による腫瘍摘出あるいは生検ではなく，神経内視鏡による第3脳室開窓術と腫瘍生検の同時手術により行われることが多い⁸⁾．Germinomaの典型例である松果体部あるいは鞍上部の腫瘍は，脳室内からの観察が容易に行えるのが通常である．しかしながら，それ以外の部位，中脳から間脳，あるいは傍側脳室に発生し，脳室内に露出していないgerminomaを経験したので報告する．

　A 25-year-old man presented with headache and consciousness disturbance. MRI revealed well enhanced mass lesions using gadolinium at bilateral thalamus and right para lateral ventricle with mild perifocal edema. Obstructive hydrocephalus was observed. On neuroendoscopic observation, the tumor was not appeared on the surface of the ventricle, therefore biopsy of the lesion was not sufficient to make a definitive pathological diagnosis. Third ventriculostomy was successful and the patient's consciousness improved. One week later, a stereotactic biopsy for right para lateral ventricle lesion made possible the histological diagnosis of typical germinoma. Post operative course was uneventful. Chemotherapy (CDDP and etoposide) following 30Gy whole ventricle irradiation resulted in the complete response of the lesion. Four years later, he has no neurological deficit except for mild disturbance in his eye movement. Our experience suggests that a synchronous lesion at thalamus and para lateral ventricle seems to be due to subependymal infiltration other than CSF dissemination.