Imaging Case of the Month June, 2010, Page 3


C. Epiploic appendagitis


Selected images through the pelvis demonstrate a 3 x 2 cm ovoid fat density lesion surrounded by inflammatory changes anterior to the proximal ascending colon. The appendix is visualized and is normal in appearance. There is no evidence of colonic wall thickening or intraperitoneal free air.


  • Epiploic appendages are 1-2 cm thick, 0.5-5cm long pedunculated fatty structures arranged in two separate longitudinal rows next to the anterior and posterior tenia coli over the external part of the colon. The vascular supply to each epiploic appendage passes through its narrow pedicle. Due to their pedunculated shape and relative mobility, epiploic appendages are prone to torsion.
  • Epiploic appendagitis is an ischemic infarction of an epiploic appendage, which may be caused by torsion or spontaneous thrombosis of a epiploic appendage draining vein. Epiploic appendagitis most commonly occurs in the sigmoid colon, in the 20-60 year old age group. The associated pain can mimic other entities such as diverticulitis, appendicitis, or omental infarction.  
  • Most commonly diagnosed on CT, epiploic appendagitis appears as a 1-4 cm ovoid fat density lesion with surrounding fat stranding adjacent to the anterior colonic wall. It may also be diagnosed on ultrasound, but with less sensitivity and specificity. On ultrasound it appears as a noncompressible ovoid or round hyperechoic mass anterior to the colonic wall, with absent blood flow on color doppler imaging.
  • Epiploic appendagitis is a self-limiting disease, with symptoms usually resolving within one week.


  • Almeida AT, et al.  Epiploic Appendagitis: An Entity Frequently Unknown to Clinicians-Diagnostic Imaging, Pitfalls, and Look-Alikes. AJR 2009;193:1243-51
  • Ozdemir S, et al. Torsion of the primary epiploi appendagitis: a case series and review of the literature. The American Journal of Surgery 2009, ahead of print
  • Singh AK, et al. Acute Epiploic Appendagitis and Its Mimics. Radiographics 2005;25:1521-34
  • Singh AK, et al. CT Appearance of Acute Appendagitis. AJR 2004;183:1303-7


Previous Page

View the Case of the Month Archives