Appendiceal diverticulitis.

We report the case of a 56-year-old man with episodic right lower quadrant abdominal pain. Preoperative evaluation included computed tomography (CT) showing a right lower quadrant phlegmon consistent with cecal diverticulitis or appendicitis. The patient was treated with a short course of bowel rest and antibiotics. Four weeks later, he had an appendectomy. The patient was found to have chronic appendiceal diverticulitis and recovered uneventfully. Histopathologic studies revealed herniated mucosa through the muscular layer associated with chronic inflammation and marked fibrosis. These findings represent appendiceal diverticulitis. Diverticulosis of the appendix is believed to be uncommon and roentgenologic diagnosis of appendiceal diverticular disease is rarely made. We discuss the diagnosis and CT findings of appendiceal diverticulitis and present a thorough review of the literature.