Epiploic appendages are small lobulated adipous tisue, protruding from the serosal surface of the colon. An epiploic appendix may undergo infarction. This may either be a result of torsion along its pedicle with the blockage of blood supply or spontaneous venous thrombosis. This infarction is followed by secondary inflammatory response (epiploic appendagitis).

Infarction of an epiploic appendage may lead to localized acute or subacute abdominal pain, so that it may mimic an abdominal surgical emergency. Primary epiploic appendagitis is a benign self-limiting disease. The symptoms usually resolve within 1 week in most patients. Misdiagnosis, therefore, may lead to unwarranted surgery. A correct imaging diagnosis of primary epiploic appendagitis can prevent unnecessary operation.

Usually this condition can mimmic appendicitis, diverticulitis or cholecystitis. CT examination can easily help to make the correct diagnosis.

Case Report

48-year-old woman was admitted to our hospital with complaint of acute abdominal pain. Her pain was located on left side of abdomen. Laboratory examination revealed slight leucocytosis. Ultrasound examination was reported to be normal. CT examination clearly identified fusiform pericolonic hypoattenuating fat containing tissue, with a hyperattenuating peripheral ring appearance (Fig-1, arrows). There is also subtle increased density of mesenteric fat, surrounding the lesion (Fig-1, arrowheads). Figure-2 and Figure-3 are axial CT images of 2 different patients with diagnosis of epiploic appendagitis. Figure-2 shows the similar findings of Figure-1. However, in Figure-3 very subtle findings are found. There is a thin perilesional hypperattenuation. We can also barely see perilesional minimal peritoneal thickeninig.


1) A. C. van Breda Vriesman et al. (1999). Infarction of omentum and epiploic appendage: Diagnosis, epidemiology and natural history. Eur Radiol, 9: 1886-1892.
2) Adriaan C. van Breda Vriesman. (2003). The Hyperattenuating Ring Sign. Radiology, 2003; 226:556–557.

Figure-1: Axial contrast-enhanced CT scans depicts a fusiform pericolonic lesion with fat attenuation surrounded by a hyperattenuating ring (arrows). There is also perilesional inflammation (arrowheads).
Figure-2: Axial contrast-enhanced CT scans of second patient clearly shows a round pericolonic lesion with fat attenuation surrounded by a hyperattenuating ring (arrows). There is also perilesional inflammation (arrowheads).
Figure-3: Axial contrast-enhanced CT scans of third patient barely shows an oval pericolonic hypoattenuating lesion surrounded by a thin hyperattenuating ring (arrows). There is also minimal adjacent peritoneal thickening (arrowheads).