Epiploic appendagitis is an inflammatory / ischaemic process involving an appendix epiploica of the colon. Usually affecting obese patients in their 2nd to 5th decades, the rectosigmoid junction is most commonly affected. An uncommon condition, it accounts for up to 7% of cases of suspected diverticulitis. The pathogenesis is thought to be due to torsion of a large and pedunculated appendix epiploica.
The characteristic CT appearance is shown: a fat-density ovoid structure adjacent to colon, with a thin high-density rim; surrounding inflammatory fat stranding. The diagnosis can be confidently made with CT, and exploratory surgery avoided. The condition can be expected to resolve in around 7 days.
An infarcted appendix epiploica may calcify, and may detach to form an intraperitoneal loose body.
Reference: Federle, M P, et al. Diagnostic Imaging. Abdomen. 1st edition, Amirsys, 2004.
Credit: Dr Jeanette TaylorCredit: Dr Laughlin Dawes