Three noncontiguous, contrast-enhanced axial computed tomography (CT)
images of the abdomen revealed a 2- x 1-cm fat-attenuated,ovoid mass
anterior to the cecum with a hyperdense center and adjacent inflammatory
stranding (Figures 1 and 2). The appendix was normal (Figure 3).
Epiploic appendagitis, a relatively rare entity, has been diagnosed
with increasing frequency during the era of multislice CT. Acute
epiploic appendagitis may clinically mimic acute diverticulitis or acute
appendicitis, as patients frequently present with acute onset,
lower-quadrant pain though they are commonly afebrile and without
The most common etiologies of this
entity are venous thrombosis (secondary) or torsion or incarceration of
an epiploic appendage within ahernia sac (primary). The common pathway
is venous outflow obstruction, leading to engorgement and inflammation
of the epiploic appendage. The most common sites of involvement are the
sigmoid colon, the descending colon, and the ascending colon (in order
of decreasing frequency). Characteristic CT features include an ovoid,
fat-density lesion measuring <5cm, typically along the anterior
aspect of the colon with adjacent inflammatory changes.2,3
Central hyperdensity is related to venous congestion. Thickening of the
visceral peritoneum may also be seen,although it tends to be associated
with omental infarct.2
Important clinical and
radiologic mimics of acute epiploic appendagitis include acute
appendicitis, acute diverticulitis, and omental infarct.2,4 Lack
of laboratory abnormalities help in eliminating acute appendicitis. The
imaging appearance is also significantly different, with a tubular
soft-tissue density surrounded by mesenteric stranding and, possibly,
free fluid seen in appendicitis. Acute diverticulitis typically
demonstrates significant bowel wall thickening and extraluminal free
air, which are absent with epiploic appendagitis.1 These
patients also commonly have fever and leukocytosis. Epiploic appendages
may become secondarily inflamed, complicating the diagnosis. Omental
infarct presents with a heterogenous soft tissue density >5 cm and
without the circumscribed, hyperattenuating ring of epiploic
appendagitis.4,5 The location may also differ, as omental
infarct is typically located anterior to the ascending or transverse
colon while epiploic appendagitis is most often found in the sigmoid
By recognizing typical imaging features of epiploic appendagitis, the
radiologist plays a central role in preventing needless surgery and
facilitating appropriate, conservative management.
- Singh, AK, Gervais DA, Hahn PF, et al. Acute epiploic appendagitis and its mimics. Radiographics. 2005;25:1521–1534.
- Legome EL, Belton AL, Murray RE, et al. Epiploic appendagitis: The emergency department presentation. J Emerg Med. 2002;22:9–13.
- Sirvanci M, Tekelioglu MH, Duran C, et al. Primary epiploic appendagitis: CT manifestations. Clin Imaging. 2000;24:357–361.
- van Breda Vriesman AC, Puylaert JB. Epiploic appendagitis and omental infarction: Pitfalls and look-alikes. Abdom Imaging. 2002;27:20–28.
- Rioux M, Langis P. Primary epiploic appendagitis: Clinical, US, and CT findings in 14 cases. Radiology. 1994;191:523–526.