テント上meningioma50例の頭蓋単純写並びに脳血管写所見の検討

A RETROSPECTIVE ANALYSIS OF PLAIN SKULL FILMS AND ANGIOGRAMS IN 50 CASES OF SUPRATENTORIAL MENINGIOMAS

はじめに

　meningiomaは全脳腫瘍の約15％を占めるが本来extracerebralに発生する腫瘍で，発育も緩徐であり非浸潤性のため巨大になるまで気付かれないことも少なくないが，その摘出手術にはglioma等に比し満足すべき結果を期待し得る。しかしそのためには術前にmeningi—omaであるか否か，またその血流を何処から受け腫瘍自体血管に富むかどうか等をよく知って手術に臨まねばならない。

　我々はテント上に発生したmeningioma50例の頭蓋単純撮影，脳血管写所見を検討し，若干の知見を得たので報告する。

Plain skull films and angiographic findings in 50 histologically proved cases of supratentorial menin-giomas, excluding intraventricular, are reviewed.

The patients ranged in age from 5 to 70 years, with the peak of frequency in the fifth and sixth decades of life. While there was an almost equal distribution between the two sexes (1.3 female to 1 male) in parasagittal, falx, and convexity menin-giomas, the sex incidence was 3. 2 female to 1 male in the tumors occurring at the base of the skull. The overall incidence was 1.9 to 1.

Nonspecific findings on the plain films, such as deformity of the sella and shift of pineal calcifica-tion, were found in 27 cases (54%). The overall incidence of hyperostosis was 36% (18 cases out of 50). Hyperostosis of the cranial vault was seen in 8 cases out of 25 having parasagittal or falx (16 cases), or convexity (9 cases) meningioma. Hy-perostotic process took place at the base of the skull of 10 patients among 25 having the tumorat the anterior or middle cranial fossa and tento-rium. Mainly destructive bone change was recog-nized in only 2 (4%) patients, who had parasagittal and convexity benign meningioma respectively. Calcification of tumor was found in only 5 (10%). The Increased vascularity was detected in 24 cases (48%). Thirty-one patients (62%) showed at least one of these specific changes on the plain films.

There was shift or displacement of the major vessels on the angiograms in 40 cases (80%). Clas-sic "tumor cloud" was demonstrated in 26 patients (52%), more frequently in parasagittal, falx, middle cranial fossa and tentorial meningiomas. Eight out of 9 tuberculum sellae meningiomas were non-vascular.

14 cases among 18 showing hyperostosis on the plain films had nonvascular tumors. While 14 out of 24 nonvascular tumors made hyperostotic changes, only 4 of 26 vascular tumors were associated with hyperostosis.

All 5 calcified tumors were nonvascular.

Selective external carotid angiogram showing the "sunburst phenomenon" was illustrated. An example of the tentorial artery (Bernasconi-Cas-sinari) in a patient of tentorial meningioma was also demonstrated.

Although approximately 60% of meningiomas may be diagnosed from the findings on the plain films or the angiograms without further study, the apllication of tomography, stereoscopic view, magni-fication, and subtraction methods will be necessary to obtain the information about the early and slight changes produced by meningioma.