[A case of colon cancer associated with schistosomiasis japonica].

A case of colon cancer associated with schistosomiasis japonica is reported. A 60-year-old man was admitted with the complaint of melena. Barium enema study revealed a colon tumor (type 1') 11 cm from the anal ring. Sigmoidectomy was performed, and no lymph node metastasis was observed. Histologically, the tumor was diagnosed as well-differentiated adenocarcinoma, and also many schistosoma ova were found not only in the lesion of the carcinoma, but also in the tissue surrounding the carcinoma. In the latter lesion, ova were observed beneath muscularis mucosae. The distributions of the ova in the anal side of the tumor were more dominant than those in oral side. We review the direct correlation between gastrointestinal tract cancer and the schistosomiasis japonica in other reports.