A 45-year-old male patient presented with pain in the right iliac fossa.
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Diagnosis: Epiploic appendagitis
Contrast axial CT scan at the level of the lower abdomen shows a fat-density ovoid structure adjacent to ascending colon, with a thin high-density rim, surrounding inflammatory fat stranding, with a central hyperdensity (black arrow in Figure 2).
Acute epiploic appendagitis is a self-limited inflammation of the appendices epiploicae. Epiploic appendages are peritoneal pouches arising from the serosal surface of the colon and are attached by a vascular stalk. The largest ones are located near the sigmoid colon and hence rectosigmoid junction is the most common site for acute epiploic appendagitis.
Epidemiology and Pathology
• Males more commonly than females
• Presents as acute right iliac fossa pain
• Torsion of epiploic appendages, with resultant ischemia has been implicated as the cause of acute epiploic appendagitis
• Prior to advent of CT, most cases were diagnosed at surgery
• Oval non-compressible hyperechoic mass at the site of maximum tenderness, adjacent to the colon, with no central blood flow on color Doppler US images.
• Oval lesion less than 5 cm in diameter with fatty attenuation abutting the anterior colonic wall with surrounding inflammatory changes
• Central area of high attenuation due to venous thrombosis can be seen.
• Omental infarction: Solitary large nonenhancing omental mass with heterogeneous attenuation, which lacks the hyperattenuating ring that is seen in epiploic appendagitis
• Acute diverticulitis: Colonic diverticula with inflammation or abscess in the mesocolon and with adjacent colonic wall thickening
• Sclerosing mesenteritis: Well-defined soft-tissue mass containing areas of fat attenuation to an ill-defined area of higher attenuation in the root of the small-bowel mesentery
• Acute appendicitis
Treated conservatively with oral anti-inflammatory medication, and antibiotics are not routinely indicated.
1. Singh A, Gervais D, Hahn P, Sagar P, Mueller P, Novelline R. Acute Epiploic Appendagitis and Its Mimics. RadioGraphics. 2005;25:1521-1534.
2. Gaillard F. Epiploic appendagitis. Radiopaedia.org. 2016 [cited 15 December 2016]. Available from: https://radiopaedia.org/articles/epiploic-appendagitis.