異所性松果体腫の1列

A CASE OF ECTOPIC PINEALOMA

I．緒言

　松果体部腫瘍はその解剖学的位置から特有な症候を現わし，その診断は困難なものではなく，したがつてそれに対する適切な処置も可能である。

　ところが，松果体にはまつたく異常がなく，脳の他の部に組織学的には明らかな松果体腫を生ずることがある。これは異所性または迷芽性（ecto—pic, heterotopic, aberrant）松果体腫といわれ脳の各所，特に脳室上衣と関係の深いところに発生し，本邦では鈴木^26）によれば松果体腫の約10.7％にみられるという。異所性松果体腫についてはStarck （1928）^27），　Globus　＆　Silbert （1931）^8）以来報告され，わが国でも赤松（1931）^1），星野（1953）^13），川淵（1957）^15），その他^{2）3）14）20）28）}によつて述べられている。これはその生ずる場所によつて複雑な臨床症状を現わし，術前の腫瘍診断もつきがたく，そのうえ発生機転，転位などについてもなお多くの問題を含んでいる。

A case report is presented of a 19-year-old boy suffering from ectopic pinealoma. The patient grew up as an intelligent boy at school without any character problem. At his age of 14, the illness started with mental disturbance, i. e. behavioral and emotional change and intellectual deterioration. He was irritated at trifles, quarreled with others and could not concentrate himself in any work. Forgetfullness and loss of memory were also observed. In the course of the illness the cli-nical picture was complicated with such neu-rological symptoms as disturbance of speech, right hemiparesis, psychomotor seizures and generalized convulsions. Ocular fundi and visual field were normal. The cerebrospinal fluid, of which pressure was elevated slightly, showed normal protein reaction. Abnormal findings in the EEG and dilated ventricle in the left hemisphere, which was confirmed by the pneumoencephalography, were suggestive of an organic brain disease of unknown ori-gin. The patient died after 5 year cours ewith recurrent convulsions.

The autopsy revealed the brain of normal look, weighing 1445g. By sectioning of the brain it was found that tumorous tissue occupiedextensively the adjacent regions to the ven-tricles in the left hemisphere: caudate nuc-leus, internal capsule and thalamic nuclei were destroyed, continuous infiltration and metastases were demonstrated in the surroun-ding structures, including corpus callosum, hypothalamic nuclei, mammillary. body, cin-gulate and hipocampal gyri. There was also involvement of a part of lentiform nucleus and internal capsule of the right hemisphere. The pineal body was normal in location and size.

Histologically, the tumor cells were charac-teristic of the pinealoma, consisting of admix-ture of two types of cells in mosaic pattern, the one being large epitheloid cells and the other lymphoid cells. Mitotic figures, giant cells and cholesterol cysts were also present. Blood vessels were dilated, and tumorous cells could be discovered in extravascular spase as well as in the lumen. Further, the infiltration was visible along the arcuate fibers beneath the cortex. Histological picture of the pineal body was normal.

The significances of involvement of the limbic system was discussed in relation to the mental disturbances of the case. The existence of growth of the tumor was consi-dered id favour of the aberrant origin.