Massimo Federico, MD
Resident, Emergency Medicine
Department of Emergency Medicine
Medical College of Georgia
Larry Mellick, MD, MS, FAAP, FACEP
Professor of Emergency Medicine and Pediatrics
Medical College of Georgia
Pearl: In patients with localized abdominal pain in the absence of severe illness, consider the possibility of epiploic appendagitis.
Presentation: A 26-year-old man presents to the emergency department with abdominal pain that was localized immediately lateral to the left abdominus rectus muscle. (See Figure 1.) The patient denies nausea or vomiting. The patient is afebrile, with a white blood cell count of 5,600. Urinalysis is leukocyte esterase negative, nitrite negative, and reveals no blood. The initial differential diagnosis list is limited to spigelian hernia, abdominus rectus muscle strain, and diverticulitis. CT of the abdomen reveals an oval, fat-containing mass abutting the sigmoid colon with surrounding inflammatory stranding of the fat. (Figures 2, 3.) The patient is discharged to home with analgesia and follow-up care.
Diagnosis: Epiploic appendagitis
Discussion The epiploic appendages are finger-like projections of adipose tissue arranged in parallel rows along the colon. These appendages number roughly 100 in the typical adult, with the average appendage being 3 cm in length.1 The term "epiploic appendagitis" was originated by Lynn et al in 1956 in describing a primary inflammatory disease of the fatty colonic appendages.2 Appendagitis primarily arises in the appendages off the sigmoid colon, with the cecum often involved.3 Appendagitis is classified as either primary or secondary. Primary appendagitis, the most common etiology, is caused by torsion of the appendage, as the pedicle is predisposed to twisting. The ischemic colonic epiploic appendage may be the source of the patient's localized pain.3,4 In secondary appendagitis, the inflammation is caused by another process such as diverticulitis, appendicitis, pancreatitis, cholecystitis, or lymphoid hyperplasia, and management is based on treatment of the primary condition.5,6
Epiploic appendagitis affects men slightly more than women, most commonly in the fourth and fifth decades of life.1 Previous reports found an association between obesity and epiploic appendagitis, but recent studies have not able to find such an association.7
The patient usually describes steady, localized pain in either lower quadrant (mimicking appendicitis or diverticulitis) that may be dull, sharp, or colicky, not migrating, with a waxing and waning quality.8 This symptom generally occurs in the absence of other symptoms of illness.5 Many patients also give a history of recent strenuous exercise or stretching.9 Nausea (36%), vomiting (21%), and anorexia (32%) may be noted, while a change in bowel habits is rare.10,11
Patients generally appear well, often with a slight temperature elevation, but no other vital sign abnormalities. The physical exam is notable only for mild, localized abdominal tenderness, rarely with rebound tenderness or rigidity. The white blood cell count with differential can be expected to be normal or only moderately elevated.4,9
The differential diagnosis list can be extensive -- to include ruptured or hemorrhagic ovarian cyst, ovarian torsion, ectopic pregnancy, colon cancer, abscess, mesenteric adenitis, and duodenal ulcer disease -- but appendicitis, diverticulitis, and gallbladder disease likely will be of highest concern on presentation.12,13
The typical CT finding is an oval-shaped, fat density lesion measuring 2-4 cm, surrounded by inflammatory changes. The diameter of the colonic wall is mostly regular without signs of thickening, in contrast to diverticulitis.9,14 The characteristic CT findings of epiploic appendagitis are known as the "ring sign," which is defined as a "round or oval pericolonic lesion with attenuation that is either the same as or higher than that of normal peritoneal fat and a thickened hyperattenuating rim that represents the ring."15 Occasionally, there is slight adjacent bowel-wall thickening, indentation of the nearby colon, thickening of the bordering parietal peritoneum, and a high-attenuation central dot within the inflamed appendage. This corresponds to the thrombosed draining appendageal vein.14,16 These CT findings may be present for up to a year.16 Ultrasound sometimes shows an oval, non-compressible hyperechoic mass with a subtle hypoechoic rim directly under the site of maximum tenderness.9,14
Epiploic appendagitis usually is a self-limited disease with spontaneous resolution, even in cases of an infarcted or torsed appendage.4 Conservative management alone is indicated when the diagnosis is made radiologically.17 Treatment should consist of oral anti-inflammatory medication. Antibiotics are not routinely indicated. Most patients recover with conservative management in fewer than 10 days.18
- Carmichael DH, Organ CH. Epiploic disorders: Conditions of the epiploic appendages. Arch Surg 1986;120:1167–1172.
- Lynn TE, Dockerty MB, Waugh JM. A clinicopathologic study of the epiploic appendages. Surg Gynecol Obstet 1956;103:423–433.
- Fieber SS, Forman J. Appendices epiploicae: Clinical and pathological considerations. Arch Surg 1953; 66:329–338.
- Vinson DR. Epiploic appendagitis: A new diagnosis for the emergency physician. Two case reports and a review. J Emerg Med 1999;17:827-32.
- Legome EL, Sims C, Rao PM. Epiploic appendagitis. Adding to the differential diagnosis of acute abdominal pain. J Emerg Med 1999;17:823–826.
- Almeida AT, Melão L, Viamonte B, et al. Epiploic appendagitis: an entity frequently unknown to clinicians -- diagnostic imaging, pitfalls, and look-alikes. Am J Roentgenol 2009;193:1243-51.
- Son HJ, Lee SJ, Lee JH, et al. Clinical diagnosis of primary epiploic appendagitis. J Clin Gatsroenterol 2002;34:435-438.
- Boulanger BR, Barnes S, Bernard AC. Epiploic appendagitis: An emerging diagnosis for general surgeons. Am Surg 2002;68:1022-5.
- Rioux M, Langis P. Primary epiploic appendagitis: Clinical, US, and CT findings in 14 cases. Radiology 1994;191:523–526.
- Sangha S, Soto JA, Becker JM, et al. Primary epiploic appendagitis: An underappreciated diagnosis. A case series and review of the literature. Dig Dis Sci 2004;49:347-350.
- Desai HP, Tripodi J, Gold BM, et al. Infarction of an epiploic appendage: Review of the literature. J Clin Gastroenterol 1993;16:323–325.
- Lien WC, Lai TI, Lin GS, et al. Epiploic appendagitis mimicking acute cholecystitis. Am J Emerg Med 2004;22:507-8.
- Legome EL, Belton AL, Murray RE, et al. Epiploic appendagitis: The emergency department presentation. J Emerg Med 2002;22:9-13.
- Molla E, Ripolles T, Martinez MJ, et al. Primary epiploic appendagitis: US and CT findings. European Radiology 1998;8:435-38.
- Rajesh A. The Ring Sign. Radiol 2005;237:301-302.
- Rao PM, Wittenberg J, Lawrason JN. Primary epiploic appendagitis: Evolutionary changes in CT appearance. Radiology 1997;204:713–717.
- Garant M. Radiology for the surgeon: Primary epiploic appendagitis. Can J Surg 1996;39:10,35.
- Singh AK, Gervais DA, Hahn PF, et al. Acute epiploic appendagitis and its mimics. Radiographics 2005;25:1521-34.