脳内腫瘤形成型全身性非Hodgkinリンパ腫—2自験例の検討と文献的考察

LOCALIZED CEREBRAL TUMOR MASS IN SYSTEMIC NON-HODGKIN'S LYMPHOMA:REPORT OF TWO CASES AND REVIEW OF LITERATURE

　抄録　脳内腫瘤を形成した全身性非Hodgkinリンパの2例にっいて報告した。症例1は82歳，症例2は70歳のいずれも男性で，それぞれ臨床病期IV,IIで脳内腫瘤が明らかとなった。組織学的にはLym—phoma Study Group分類でいずれもびまん性大細胞型と診断され．一方免疫学的には腫瘍細胞はB細胞，T細胞と異なった性格を有していた。CT上腫瘤は側脳室に近接して存在し，辺縁整で均質な増強効果を示し，その周囲には浮腫を伴っていた。症例2では脳血管撮影で腫瘍紅織の脳室上衣下への進展が示された。両症例とも髄液中からリンパ腫細胞が証明され，これは治療効果に対応した消長を示し，神経放射線所見も含めて脳室を介する髄腔内播種と考えられた。治療についてはそれぞれ放射線照射，ステロイドが有効であった。これら2例を含めた文献的考察から，その病態は全身性非Hodgknリンパ腫の髄膜浸潤とは異なり，組織学的特性，CT像，その局在および治療効果の面から中枢神経原発非Hodgkinりンパ腫との類似性が示された。

The pathophysiology of cerebral tumor mass in cases of systemic non-Hodgkin's lymphoma is not well known. We experienced with two cases with this lesion. The purpose of this report is not only case presentation but also an analysis of cases from the literature from the clinical, radiological, his-tological, immunological and therapeutic aspects.

Case 1 was a 82-year-old man who had weakness in the right arm and for the past month. For about two years he had been received anticancer chemotherapy because of a systemic malignant lymphoma at another hospital. Neurological ex-amination revealed disorientation and right hemi-paresis. Microscopic and immunological studies of the biopsy specimen of the enlarged supraclavic-ular node showed a non-Hodgkin's B-cell lym-phoma of the diffuse large cell type according to the Lymphoma Study Group (LSG) classification. The clinical stage (CS) of the lymphoma was IV except for the CNS lesion by systemic examina-tion including lymphography. CT scan on admis-sion revealed remarkable enhancement of a nodular high density area near the lateral ventricle, ac-companied by surrounding low density. Angio-graphy failed to reveal a tumor stain. CSF cyto-logy was positive although no pleocytosis was observed.

Case 2 was a 70-year-old man who had weakness of the right foot for two weeks. About three years ago he underwent orchiectomy for a testicular tumor at another hospital. Neurological examina-tion revealed disorientation, memory loss and right hemiparesis. Histological reexamination of the resected testicular tumor specimen disclosed a non-Hodgkin's lymphoma of the diffuse large cell type in the LSG classification. CS was II except for the CNS lesion. CT scan also showed remarka-ble enhancement of a mass in the caudate nuclei and upper portion of the thalamus, accompanied by a surrounding low density. Angiography showed a slight tumor stain and narrowing of the thalamostriate vein. CSF revealed pleocytosis in-cluding malignant cells.

Radiation or administration of betamethasone brought about reduction of the high density area and disappearance of tumor cells in CSF in these cases.

The literature was reviewed concerning cerebral tumor masses in systemic non-Hodgkin's lym-phoma. It was found that cerebral tumor masses in systemic non-Hodgkin's lymphoma were similar to those in primary non-Hodgkin's lymphoma of the brain on the basis of their hitological charac-teristics, CT scan findings, location and therapeutic efficary.