比較的短期間のうちに形態変化を来した胃悪性リンパ腫の1例

Gastric Malignant Lymphoma Presenting with Rapid Changes in Shape in a Relatively Short Period, Report of a Case

要旨　患者は77歳，男性．心窩部痛のため胃集検を受診，胃体部の粘膜異常を指摘された．精検で前庭部前壁側に，周辺部が褪色調のなだらかな盛り上がりを示し，中央部が結節状を呈する不整な隆起性病変が認められ，生検で形質細胞腫または形質細胞への分化を示す悪性リンパ腫と診断され，胃全摘術を施行．手術標本の組織学的検索で広範囲にわたるmixed typeのlymphoma cellの増生が認められ，また，リンパ腫病巣とは独立して広範に腫瘍性形質細胞が存在した．比較的短期間のうちに病像が著しく変化し形質細胞腫との鑑別が困難であった胃悪性リンパ腫の1例を報告し，胃癌および胃形質細胞腫との鑑別について考察を加えた．

　One of the crucial points in diagnosing gastric malignant lymphoma (GML) is to differentiate it from carcinoma. GML tends to be mistaken for carcinoma because of the similarities to carcinoma in appearance and much lower incidence than that of carcinoma.

　A 77-year-old male complaining of epigastric pain was diagnosed as having gastric plasmacytoma or gastric malignant lymphoma with marked plasma cell differentiation based on biopsy findings which included neoplastic proliferation of plasma cells. Total gastrectomy was performed after follow-up with x. ray and endoscopic examinations for 3 months, during which remarkable morphological changes of the lesion occurred in a relatively short period of time. Surgical specimen showed multiple lesions of various appearances in a wide range of the stomach, while the gastric wall retained softness. If we pay attention to these characteristics differential diagnosis of GML from carcinoma would not be so difficult.

　Histological examination of the surgical specimen revealed diffuse neoplastic plasma cell proliferation in the lamina propria mucosa apart from the lymphoma lesions. Such case as this is difficult in differentiating lymphoma from plasmacytoma of the stomach by biopsy specimen.