直腸原発性悪性リンパ腫の1例

Primary Malignant Lymphoma of the Rectum, Report of a Case

　大腸の悪性腫瘍の大半は癌であり，悪性リンパ腫はまれである．消化管悪性リンパ腫は消化管の壁内より発生した原発性のものと，全身に拡がったリンパ節性悪性リンパ腫の部分病変のものとに分類されるが，われわれは直腸に原発した悪性リンパ腫を経験したので，症例を報告し若干の文献的考察を加えてみた．

　A 71-year-old woman was admitted to our surgical clinic because of diarrhea, tenesmus and bloody stool.

　Barium filled picture of the rectum disclosed a protuberant lesion, 6.8×6.5 cm in size, 3 cm oral from the anal ring. Rectosigmoidoscopy revealed a hemorrhagic tumor occupying two third of the bowel wall. The surface of the tumor was uneven. The specimen of the biopsy was diagnosed as an inflammatory granuloma.

　Laparotomy was performed and there was found no lymph node swelling in the abdominal cavity. The tumor was resected by the rectal amputation (Miles' operation). The local lymph nodes beside the tumor of the rectum were excised but were not involved. Metastasis to the liver was not observed. This case was classified into Dukes' B.

　The resected tumor grossly appeared elastic, semispherical and red brown. There was irregular ulceration on the surface of the tumor. The cut surface had a uniform and fleshy appearance and its superficial layer was covered by necrotic tissue in part. The histological study revealed that the tumor was diffuse malignant lymphoma (lymphoplasmacytoid type, IgG. k-type monoclonal proliferation) by WHO classification of malignant lymphomas.

　The postoperative course was uneventful.