Colonic cancer and associated diverticulitis.

In a total group of 385 cases of colonic cancer, there was evidence of associated diverticulitis in 42 cases. Of these, 92% of the patients were over 60 years of age. In 45% of the cases the coexisting lesions were located in the sigmoid colon. It is suggested that cancer of the colon contributes to the development of diverticulosis and diverticulitis; this is confirmed by the finding of 52.8% of the total group of diverticulosis (98 cases) complicated by diverticulitis. Signs of diverticulitis may mask the presence of cancer, and the diagnosis of associated lesions is sometimes difficult. The patient's history and repeated radiographic studies play an important role in the detection of associated cancer. The final diagnosis is confirmed by pathologic examination.