頭蓋外転移をきたしたHemangiopericytic meningiomaの1例—その電顕像と文献的考察

Electron Microscopic Study of Metastatic Hemangiopericytic Meningioma

I．はじめに

　Hemangiopericytic meningiomaは髄膜腫のO．9-3.1％^11,22）を占めるにすぎないが，再発や頭蓋外転移を高率にきたし，予後不良のことが多い．また，その細胞起源の詳細は現在なお明らかでない．

　最近，過去に4回の開頭術をうけ，初回手術後6年目に肋骨，肝臓，頸椎および胸骨に頭蓋外転移をきたした症例を経験し，電顕的観察から原発巣と転移巣でleio-myoblastic differentiationを示唆する所見が得られ，その発生由来について検討したので，文献的考察を加えて報告する．

Electron microscopic observations in a case of metastatic hemangiopericytic meningioma was pre-sented. Cell origin of this tumor was discussed in detail from the point of the leiomyoblastic differentia-tion.

The patient was a 49-year-old woman who was oper-ated four times in the past for the cerebellar tentorial and the left parasagittal tumors. Six years after the first operation, metastatic lesions were found in the rib, the liver, the cervical vertebra and the sternum. Specimens were prepared from the intracranial and the rib tumors.