Descending Colon Cancer Coincident with Schistosoma japonicum in an 89-year-old Male.

An 89-year-old male came to the hospital with a complaint of abdominal distension. Abdominal computed tomography showed wall thickening in the descending colon and marked dilatation of the proximal colon, and lower gastrointestinal endoscopy demonstrated a stenosis in the descending colon. Although a biopsy from the stenotic lesion showed calcified eggs of Schistosoma japonicum with no malignant findings, we suspected malignant involvement, so we performed a descending colectomy with regional lymph node dissection. Pathological examination revealed a moderately differentiated adenocarcinoma. The colon cancer was diagnosed as pT4bN0M0, Stage IIc. The patient's history as a resident of one of the formerly endemic areas of Japan suggests that he may have carried S. japonicum for a long time, and that it may have contributed to carcinogenesis.