'Malignant' diverticulitis: a clinical entity.

A form of severe diverticulitis exists that is characterized by (1) phlegmonous inflammation of the sigmoid and rectosigmoid colon, often extending below the peritoneal reflection, (2) frequent fistulization to skin, urinary bladder, and small intestine, (3) frequent colonic obstruction, and (4) high postoperative morbidity and mortality. The clinical similarity to granulomatous colitis is very apparent, but pathologic findings are consistent with severe diverticulitis rather than granulomatous colitis. The term "malignant" diverticulitis is suggested because of the progressive nature of the disease process and the frequency of severe morbidity associated with it. Seventeen patients have been studied since 1965, comprising approximately 7% of patients operated on for diverticular disease at Cedars-Sinai Medical Center.