Computed tomography findings mimicking appendicitis as a manifestation of colorectal cancer

Abstract

The primary computed tomography (CT) signs of appendicitis can also be seen with other inflammatory or neoplastic processes. We report on two cases in which appendiceal dilatation and peri-appendiceal fluid or stranding were the dominant imaging manifestations of colorectal carcinoma in the ascending colon. This study highlights the need to closely examine the ascending colon in patients with a suspected CT diagnosis of acute appendicitis, since these findings may be secondary to an inconspicuous colorectal carcinoma.

Fig. 1

(A) Axial contrast-enhanced CT section of the lower abdomen in a 78-year-old woman with right-sided abdominal pain. The appendix (arrow) is fluid filled and distended to a diameter of 10 mm, with surrounding peri-appendiceal fluid. (B) Coronal curved planar reformatted contrast-enhanced CT section shows the terminal ileum (asterisk) is mildly dilated and demonstrates the small bowel feces sign. A subtle short segment of concentric wall thickening (between arrows) is seen in the ascending colon, suggestive of primary colonic carcinoma (subsequently confirmed on endoscopy and biopsy).

Fig. 2

(A) Axial contrast-enhanced CT section of the abdomen in a 68-year-old asymptomatic man with a history of renal cell carcinoma undergoing routine surveillance. CT demonstrates a dilated fluid-filled appendix (arrow) to a diameter of 11 mm. Eccentric wall thickening of the cecum and ascending colon (asterisk) is visible. (B) Coronal curved planar reformatted contrast-enhanced CT section shows the dilated fluid-filled appendix (black arrow) and better demonstrates eccentric wall thickening of the cecum and ascending colon (white arrow).