Prednisoloneが著効を呈した脳原発悪性リンパ腫の1例

A CASE OF PRIMARY MALIGNANT LYMPHOMA OF THE BRAIN WHICH SHOWED A REMARKABLE RESPONSE TO PREDNISOLONE

　抄録　最近，prednisoloneが著効を呈し，診断が困難で，全経過20ヵ月で死亡した脳原発悪性リンパ腫の1例を経験した。患者は59歳の男性，精神症状にて発症し，CTスキャン上側脳室前方にhigh density areaをみとめたが，prednisolone投与にて消失した。左片麻痺のため再入院した際には右基底核部にhighdensity areaをみとめたが，　prednisoloneの投与にて縮小した。放射線療法ならびに化学療法を併用したが，結局左基底核部に再発し死亡した。剖検にて左基底核にmass lesionが認められた。光顕では脳室上衣下を中心に広汎に腫瘍細胞の浸潤が認められた。すなわちmass lesionを形成すると同時にびまん性浸潤の進展も示した。また，ステロイドホルモンの投与によりCTスキャン上mass lesionが一時的に消失したとする報告は，われわれの調べえた限りでは本症例のみであつた。

We have recently had a case of a patient with primary malignant lymphoma in whom the diagno-sis was difficult and prednisolone was remarkably effective. The patient was a 59-year-old man. Mental signs developed rapidly over a period of approximately 1 month. On admission, he was confused ; his orientation was disturbed and his impressibility and understanding were markedly decreased. CT scan on admission revealed aremarkable enhancement of a nodular high density area in front of the lateral ventricles, accompanied by a surrounding diffuse low density. Angiogra-phy failed to reveal a tumor stain. When predni-solone was administered to the patient, the high density area disappeared and neurological findings returned to normal. After that, left hemiparesis occurred twice and disappeared following the administration of prednisolone. After that, how-ever, he was readmitted to our hospital because his left hemiparesis advanced rapidly. CT scan revealed a high density area in the right basal ganglia. It also decreased in several days after the administration of prednisolone. Malignant lymphoma was strongly suspected by operation. He was then readmitted to our department because of a gait disturbance, decrease in impressibility, and incontinence of urine about one year and a half after onset. CT scan revealed symmetrical ventricular dilatation. Although a shunt procedure was considered, gastrointestinal bleeding occured,followed by rapid deterioration of his general condition and neurolgical signs. CT scan 2 days before death revealed a mass lesion in the left basal ganglia. Autopsy revealed that a gelatinous tumor, primarily in the left basal ganglia, was verified macroscopically, but that there was no specific tumor at any other site. Light microscopic examination revealed a diffuse infiltration of tumors cells around the blood vessels in the sub-ependymal area of the lateral ventricle. Because tumor cells were not verified in any other organ, primary malignant lymphoma of the brain was considered.

These results suggest that in the development of malignant lymphoma, once a mass lesion is formed, it is widely invasive especially along blood vessel walls. As far as we know, there have been no reports which describe a tumor decreasing or disappearing on CT scan following administra-tion of steroid hormone alone.