Chronic anisakiasis of the ascending colon associated with carcinoma.

Chronic anisakiasis of the colon is rare and difficult to diagnose. We report a case of chronic anisakiasis associated with advanced colonic carcinoma. A 69-year-old man was admitted for abdominal pain, diarrhea, and urticaria. Right hemicolectomy was performed because of an obstruction of the ascending colon and a palpable tumor of the right lower abdomen. The lesion was thought to be located in the deeper layers of the ascending colon. Preoperative examinations failed to detect the coexistence of anisakiasis and carcinoma of the colon. The anisakis was identified morphologically in the intestinal wall of the resected specimen and by an elevated titer of an IgE antibody specific to the parasite. Seventy-five cases of colonic and rectal anisakiasis, including the present case, have been reported in Japan. This is the only reported case of anisakiasis to appear in association with colonic carcinoma.