Perforated diverticulum of the transverse colon

We report a case of perforated diverticulitis of the transverse colon. The preoperative diagnosis of perforated appendicitis was made on the basis of findings of both ultrasonography and CT. At surgery, an inflammatory mass resembling carcinoma was found in the transverse colon, and segmental resection was then performed. Diverticulitis of the transverse colon is rare, and there have been few reports in the English-language medical literature. This report describes a true diverticulum of the transverse colon that presented as acute diverticulitis.