Extensive inflammatory change in the right iliac fossa is present involving the caecum, terminal ileum and appendix. The appending is dilated (9mm) and hyperemic. The mucosa near the tip of the appendix is not visualised with apparent defect of the mucosa as it enters a poorly circumscribed non-walled-off fluid collection measuring ~3cm in diameter.
There is a moderate length segment of terminal ileum just upstream of the ileo-caecal valve that demonstrates wall thickening, mural stratification and surrounding stranding. There is also free fluid tracking within the adjacent mesentery as well as subcentimetre mesenteric lymph nodes more centrally. No free intraperitoneal gas. Small volume free fluid also tracks inferiorly into the pouch of Douglas.
No upstream small bowel dilatation. No focal hepatic lesion identified. No portal venous gas identified. The kidneys, gallbladder, adrenals, pancreas and spleen are unremarkable. Circumaortic left renal vein noted.
Conclusion:
Extensive right iliac fossa inflammation, with close relationship to an abnormal appendix suggesting that appendicitis, despite age of the patient, is the likely diagnosis. Defect of the mucosa at the tip of the appendix adjacent to a fluid collection is suspicious for perforation.