Figure 11. (a) 83-year-old male with acute onset of right lower quadrant pain. CT demonstrates marked concentric caecal thickening (arrow). (b) CT images slightly caudal demonstrates a dilated fluid filled appendix with an enhancing appendiceal wall consistent with appendicitis. Due to the nature of the caecal thickening, caecal carcinoma with obstruction and secondary appendicitis was diagnosed. Both findings were confirmed at surgery.