Simulation of colonic carcinoma by ischemia.

Nine cases of colonic ischemia are presented in which an initial diagnosis of carcinoma was made from roentgenographic, endoscopic, or intraoperative appearance of the lesion. The clinical features were insufficient to differentiate colonic ischemia from carcinoma. In 7 patients a barium enema was interpreted as, or consistent with, carcinoma. In 3 of these patients colonoscopy also suggested malignancy. In 2 patients, endoscopy suggested a neoplasm but no barium enema was performed. Endoscopic biopsies when performed were negative for malignancy. Three patients were considered to have cancer from the gross appearance of the lesion at laparotomy. Routine use of both barium enema and colonoscopy in patients with suspected colonic neoplasms will usually identify the ischemic nature of lesions incorrectly diagnosed by one technique or the other. In the uncommon patient in whom both studies suggest a neoplasm, but biopsy specimens are negative for tumor, repeat studies 7-10 days later may identify the evolving nature of ischemic lesions and obviate the need for surgery. When no changes are seen, prompt laparotomy is indicated.