Know the name: acute epiploic appendagitis-CT findings and review of literature

Abstract

Epiploic appendages are normal pedunculated peritoneal fat containing outpouchings bordering tenia coli on the anti-mesenteric surface of the colon, extending from caecum to the rectosigmoid. Functions are currently unknown, though some postulate them a blood reservoir. The epiploic appendages can become inflamed, with clinical presentations mimicking that of diverticulitis or acute appendicitis. However, unlike acute diverticulitis or appendicitis, epiploic appendagitis are treated conservatively with antibiotics. Currently, the estimated rate of correct preoperative diagnosis of epiploic appendagitis is 2.5%, but due to benign nature of epiploic appendagitis, it is important to appropriately diagnose it preoperatively and thus preventing unnecessary surgical interventions. Clinical features include focal area of pain, often with normal white blood cell count, that often is common in other differential diagnoses. CT scan plays a crucial role in diagnosis and shows an oval fatty density solid lesion along anterior colonic wall surface, surrounded by a rim of fat stranding. Treatment is conservative and involves use of anti-inflammatory medication.

Keywords: Epiploic appendagitis; acute abdomen; appendicitis; computed tomography; diverticulitis; inflammation.

Figure 1

An inflamed epiploic appendage, appearing as an oval structure with central fat density with a hyperattenuating rim, visualized in the right paracolonic region can be a clinical mimicker of acute appendicitis. Coronal (A), axial (B) CT images of the abdomen and pelvis reveals an oval fat density structure in the right paracolonic region, showing hyperattenuating center. Note a hyperattenuating rim surrounding the lesion, along with subtle inflammatory changes highlighted by the white arrows, best appreciated on the enlarged views (C). The lesion in this location can mimic acute appendicitis.

Figure 2

An inflamed epiploic appendage in the left iliac fossa region can clinically mimic acute episode colonic diverticulitis. Coronal (A), axial (B) CT images of the abdomen and pelvis reveals an oval fat density structure in the left iliac fossa region, showing hyperattenuating center. Note a hyperattenuating rim surrounding the lesion, along with subtle inflammatory changes, best appreciated on the enlarged views and highlighted by the white arrows (C). The lesion in this location can mimic acute diverticulitis.