The sigmoid and the cecum are the most common sites of appendagitis, with the former more frequently affected. Because the appendages tend to be larger in the sigmoid, epiploic appendagitis and its accompanying symptoms are most often experienced in the left lower quadrant. However, at least one case is known of a patient with a massive sigmoid that extended into the right iliac fossa who presented with pain in the right lower quadrant. Also, at least one reported case details epiploic appendagitis located within an inguinal hernia sac.
Primary epiploic appendagitis is most often mistaken for diverticulitis and appendicitis, depending on the location (diverticulitis in cases of left lower-quadrant pain and appendicitis in cases of right lower-quadrant pain). Of note, primary epiploic appendagitis was the final diagnosis made in 2%-7% of abdominal CT scans that were performed to rule out diverticulitis, and in 1% of CT scans that looked for appendicitis.[13,14] The pain may also mimic that of a hernia, renal or ureteric colic, omental infarction, acute cholecystitis, and pelvic inflammatory disease.
The rarity of primary epiploic appendagitis is evidenced by the fact that Sand and colleagues were only able to include 10 patients in their study over 3 years, despite conducting their investigation in an urban academic surgical ED. Although it can present at any age, epiploic appendagitis most commonly presents in the fifth decade of life; it has a slight male preponderance.[1,3,16]
Whether or not this condition is more common in overweight or patients with obesity is controversial; multiple studies support either view. The literature does support an increased incidence in overweight or obese patients.[2,12,17] Hanson and Kam reported that epiploic appendagitis is more common not only in patients with obesity, but also in those who have recently lost weight. Strenuous exercise or physical labor by the unaccustomed patient is often recorded as the inciting event.[9,19,20]
A patient with epiploic appendagitis generally presents with an acute onset of sharp, localized, nonmigratory abdominal pain, most often in the left lower quadrant (as detailed above). The pain may be aggravated by movement, deep breathing, or coughing. In contrast to other acute abdominal processes (appendicitis, diverticulitis), patients do not generally present with fever, anorexia, nausea, or vomiting. Typically, laboratory study values, including a complete blood cell count, complete metabolic profile, and urinalysis, are within normal limits; however, some patients may have mild leukocytosis.[1,2] Sand and colleagues reported an elevated C-reactive protein (CRP) level in two out of 10 patients in their case series, and hypothesized that the necrosis of epiploic appendagitis triggers an inflammatory response, thereby elevating the CRP level.
Before the advent and common use of CT, the diagnosis of primary epiploic appendagitis was made by exploratory laparotomy, wherein the inflamed appendage was then ligated and excised. Proper identification of this condition using radiologic studies, specifically abdominal and pelvic CT, may prevent unnecessary surgical exploration and its associated costs and complications. A study by Rao and colleagues revealed that the average cost per misdiagnosed patient in this situation was $4117.
On CT, epiploic appendagitis is represented by a round or oval lesion, typically 2-4 cm in diameter, in close apposition to the colonic wall. More than one half of these cases are located in the sigmoid colon. Surrounded by periappendageal and pericolic fat stranding, the attenuation of the lesion itself is similar to that of fat, but there is often a thin rim of increased density. A central section of hyperattenuation representing an area of venous thrombosis may be intermittently present.[1,4] The proximal colonic wall is not normally thickened, which helps differentiate this condition from diverticulitis; however, the adjacent visceral peritoneum may occasionally be thickened.
Identifying epiploic appendagitis with ultrasonography is generally difficult, but the appendage has been described as an oval, hyperechoic, noncompressible mass with a fine hypoechoic rim at the point of maximal tenderness, adjacent to the colon. On color Doppler ultrasonography, lack of central blood flow is observed; this is an important differentiating factor from appendicitis, which would demonstrate increased blood flow.[1,20,23,24]
MRI is not typically performed in this patient population; however, epiploic appendagitis can certainly be identified on MRI. T1- and T2-weighted images demonstrate a focal lesion, with a signal intensity similar to that of fat. The addition of contrast to T1-weighted imaging demonstrates a fatty lesion with rim enhancement.
Radiologic changes can persist for weeks, but they generally resolve within 6 months of the acute episode.
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Cite this: Noah Gudel, Lisa M. Rock. Gastro Case Challenge: Excruciating Abdominal Pain in a Woman Taking Benzodiazepines and Narcotics - Medscape - Dec 07, 2022.