悪性化せる頭蓋内間葉性混合腫瘍の1例

ON A CASE OF MALIGNANTLY CHANGED MESODERMAL MIXED TUMOR IN PRIMARY INTRACRANIAL ORIGIN

I．緒言

　頭蓋内に原発する，いわゆる混合腫瘍の中で，"簡単な"混合腫瘍，すなわち混在する組織成分が，いずれも間葉性成分のみからなるものは，"複雑な"混合腫瘍，すなわち，三胚葉性混合腫瘍—奇型腫—に比して非常にまれなものである。

　最近，当教室において，この頭蓋内の間葉性混合腫瘍が一部悪性化し，経過中に突然急速な発育を示し，かつ，脳内で播種を起こしていることを手術により確かめえた1例を経験したので，若干の文献的考察を加えて報告する。

Comparing with the incidence of teratoid and tera-tom of primarily intracranial origin, pure mesodermal mixed tumor is said to be extremely rare.

A case of mesodermal mixed tumor ascertained by operation was reported. This tumor showed malignant change in a part of it, sudden rapid growth and dis-semination of two daughter tumors. 21 aged man had complained of transient right sided hearing disturbance about one year before ad-mission.

Four months prior to admission, he suffered from visual disturbance and one month later symptoms of ncreased intracranial pressure appeared. Two monthsprior to admission, a nut sized tumor was able to be palpated over the scalp at the right temporal region, and these made him bring to our clinic. All these symptoms and signs coursed in one year.

It was proved by operation that a nut sized tumor protruded through the temporal bone was a part of a tennis ball sized tumor (40g) located intradurally under the temporal lobe. Two daughter tumors (each 10g) were extirpated. These tumors were solitary and had no communication with each other. Histological examination revealed that it was an osteochondroma. The extradural part of the big tumor and two daughter tumors showed malignancy. These tumors were not considered as multicentric but that the big tumor had undergone malignant change and produced the dissemination of these daughter tumors.