Hemangiopericytoma−その電顕的微細構造と細胞培養とにもとづく本質の検討

HEMANGIOPERICYTOMA IN SCALP:CASE REPORT WITH SPECIFICAL REFERENCE TO ITS HISTOGENESIS BY ELECTRONMICROSCOPIC AND CELL-CULTURE STUDIES

はじめに

　1923年Zimmermannは毛細血管の外側に，それをとり囲む細胞があり，pericyte （血管周皮細胞）と名づけ，血管平滑筋細胞へ移行するものと考えた^28）。

　1942年Stout　＆　Murrayは，Zimmermannのperi—cyteより発生したと考えられる腫瘍を9例報告しhe—mangiopericytoma （血管周皮細胞腫）と名づけた^23）。彼等はその内の3例にrounded cellとspindle-shapedcellの混合型を観察し，一応の根拠のもとにpericyteがmodified smooth muscle cellであることを裏づける所見であると考えた。しかし，その後のhemangiope—ricytomaの報告例では，pericyteとは血管壁平滑筋細胞と一線を画するものであり，その最大の根拠として筋原線維を有しない点が強調された^{5）8）24）}。

This is a case of 48 years old Korean male who had started to have symptoms of visual disturbance, headache, and multiple tumors in the scalp, the shoulder, and the chest wall. The tumor surgically removed from the scalp histologically revealed hemangiopericytoma in the cathegory of Stout and Murray. His clinical course was precisely reported. The histogenesis of pericyte and clinical features of hemangiopericytoma were discussed with review of literatures.

(1) The histogenesis of hemangiopericytoma

Electronmicroscopically, fine filaments (50-90Å in diameter) were obviously observed in the cyto-plasm of tumor cells. Rich glycogen granules and a moderate amount of mitochondria were also noticed. Morphological changes of tumor cells in monolayer culture were also studied. Fibroblastoid cells stdrted to proliferate on the third day. Their forms gradually changed into that of spindleshaped after one week culture. The electronmicroscopic study of cultured cells (the third day) revealed fine filaments in their cytoplasm.

These findings suggest that pericytes might be originated from vascular smooth muscle cells. It is, therefore, reasonable that this tumor should be called as vascular leiomyoblastoma rather than hemangiopericytoma.

(2) Clinical features of hemangiopericytoma

It is difficult to differentiate the intracranial hemangiopericytoma from so-called angioblastic meningioma because of its high frequence in meninges.

In spite of their benign histological pictures of hemangiopericytoma, the clinical prognosis is mostly poor. Literatures on clinical data of emangiopericytoma were reviewed. The surgical removal should be recommended. Radiation ther-apy or chemotherapy is not effective and permanent cure can not be expected.