Management of carcinoma discovered unexpectedly at operation for acute appendicitis.

This review of 900 patients who underwent colon resection for carcinoma identified 33 patients who were explored with the preoperative diagnosis of appendicitis. In 19 patients, the appendix was acutely inflamed secondary to obstruction of the appendiceal lumen. The other 14 patients had perforating or obstructing cancer of the ascending colon or cecum. The clinical clues of a prolonged symptom history, weight loss, anemia, and a palpable mass were frequently, but not invariably, present. Results of contrast enema, computerized axial tomography, and colonoscopy in this select group were frequently misleading. The diagnosis is best made in the operating room by the thoughtful appendectomist. I recommend prompt resection and an appropriate cancer procedure in these patients. Carcinoma masquerading as appendicitis occurs more often than is generally realized and will be seen more frequently as our aging population increases.