Epiploic Appendagitis

LLQ Pain in 44 F • Xray of the Week

This 44 year old female presented to the Emergency Department with sudden onset left lower quadrant pain. There was no fever or vomiting. What is the diagnosis?

Fig. 1 Axial (left) and coronal (right) CT with contrast. There is a well defined region of fat attenuation with surrounding mesenteric edema with a central dot representing a thrombosed vein, diagnostic of epiploic appendagitis.

Fig. 2 Axial (left) and coronal (right) CT. Central thrombosed vein in epiploic appendage (blue arrow) with surrounding mesenteric edema diagnostic of epiploic appendagitis.

Fig. 3 A Second patient with epiploic appendagitis in RLQ mimicking appendicitis clinically and on CT: Central thrombosed vein in a fatty lesion with a thin high attenuation rim (blue arrows on coronal images and red arrow on axial image). Findings consistent with epiploic appendagitis. Case courtesy of Geoffrey Sigmund, MD.

Fig. 4 A third patient with subtle epiploic appendagitis in LLQ mimicking diverticulitis clinically. CT demonstrates the central thrombosed vein in a fatty lesion with a thin high attenuation rim (yellow arrows). Findings consistent with epiploic appendagitis.

Fig. 5 A different patient with ascites outlining normal epiploic appendages (blue arrows)

Discussion:

Epiploic appendagitis is an uncommon inflammatory process of the epiploic appendices of the colon which can mimic diverticulitis clinically. The etiology is probably due to torsion of a large epiploic appendage or spontaneous thrombosis of a vein in the appendage. The hallmark appearance of epiploic appendagitis on CT scan is a well defined 2-4 cm region of fat attenuation, a thin surrounding high attenuation rim, surrounding mesenteric edema, and a central dot representing a thrombosed mesenteric vein. (Fig. 1-2) If present in the right lower quadrant, it may also be confused clinically with appendicitis. (Fig. 3) The findings on CT may be subtle as seen in Figure 4. The normal epiploic appendages are usually not visualized on CT unless outlined by free fluid. (Fig. 5) The radiologist plays an important role in the management as a correctly interpreted CT scan alerts the clinician to the diagnosis and the fact that it is self-limiting. This often prevents unnecessary surgery. Treatment is anti-inflammatory drugs and symptoms usually resolve within a week.

References:

1. Singh AK, Gervais DA, Hahn PF et-al. Acute epiploic appendagitis and its mimics. Radiographics. 25 (6): 1521-34.

2. Purysko AS, Remer EM, Filho HM et-al. Beyond appendicitis: common and uncommon gastrointestinal causes of right lower quadrant abdominal pain at multidetector CT. Radiographics. 2011;31 (4): 927-47.

Kevin M. Rice, MD is the president of Global Radiology CME

Dr. Rice serves as the Chair of the Radiology Department of Valley Presbyterian Hospital in Los Angeles, California and is a radiologist with Renaissance Imaging Medical Associates. Dr. Rice has made several media appearances and given as part of his ongoing commitment to public education. Dr. Rice's passion for state of the art radiology and teaching includes acting as a guest lecturer at UCLA. In 2015 Dr. Rice founded Global Radiology CME to provide innovative radiology education at exciting international destinations, with the world's foremost authorities in their field. Due to his online teaching activities, Dr. Rice was nominated and became a semifinalist for a "Minnie" award for the Most Effective Radiology Educator in 2016.

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