False-negative barium enema in patients with sigmoid cancer and coexistent diverticula.

The false-negative rate of barium enema examinations for the recognition of polypoid sigmoid cancer was evaluated in 167 patients with histologically proven carcinoma. The cases were classified according to the coexistence of sigmoid diverticula. In patients with less than 15 diverticula, 3.1% of lesions were missed, while in those with more than 15 diverticula, 20.4% of tumors were undetected. The overall error rate was 7.2%. Extensive diverticulosis is an important factor limiting the sensitivity of barium enema examinations for the evaluation of sigmoid masses.