潰瘍性大腸炎に合併した大腸悪性リンパ腫の1例

Colonic Malignant Lymphoma Complicating Ulcerative Colitis, Report of a Case

要旨　潰瘍性大腸炎に悪性リンパ腫を合併した症例を経験した．患者は39歳男性で，発熱・下痢・腹痛を主訴に来院し，注腸X線検査，内視鏡検査と生検で全結腸炎型の潰瘍性大腸炎と診断された．内科的治療を続け一時軽快したが，約5年後に再燃し，発熱・下血により全身状態が悪化したため，止むなく全結腸・直腸切除兼回腸瘻造設術を施行した．切除標本の詳細な病理組織学的検索で，多発性の悪性リンパ腫（びまん性リンパ腫・大細胞型，T細胞型リンパ腫）の合併が確認された．潰瘍性大腸炎に合併する悪性リンパ腫の報告例は非常に少なく，両疾患の因果関係もいまだ詳細には解明されていない．本症例では，反応性か腫瘍性か鑑別に苦慮したT細胞性リンパ球の増殖が優位であり，リンパ腫との移行が示唆された．

　We report a case of ulcerative colitis (complicated by malignant lymphoma), in a 39-year-old man. He had a 5-year history of ulcerative colitis confirmed by barium enema, colonofiberscopy and histology in 1976. Therapy using prednisolone and salazopyrin brought him symptomatic relief. However, in 1981, he sufferred from increasingly aggravated diarrhea, fever and abdominal pain for two months, with little improvement under conventional treatment. He had severe rectal bleeding, and a panproctocolectomy was performed on July 1, 1981.

　Histologic examination of the entire colon and rectum disclosed lesions of ulcerative colitis without lymphoma, and multiple ulcerative lesions with malignat lymphoma. The lymphoma was of diffuse, large-cell type with T cell phenotype characterized by LCA (＋), MT-1 (＋), UCHL-1 (＋), MB-1 (－) and LeuM1 (－). The resected terminal ileum had no definite lesion of any type. Proliferating lymphoid cells were found in the submucosa, in either scattered or abnormal aggregation, with or without close association with the ulcerative colitis and the lymphoma lesion. These lymphoid cells showed predominantly T cell phenotype. The findings suggest a hyperreactivity of T cell lineage, and a possible relationship to the occurrence of T cell lymphoma in the present case.

　To our knowledge less than 30 cases of malignant lymphoma in patients with ulcerative colitis have been described in the literature.