Epiploic appendages are adipose structures protruding from the colon and distributed from the caecum to the rectosigmoid junction. The biggest appendages occur in the caecum and the sigmoid colon.
Primary epiploic appendagitis is an acute abdominal condition which is clinically almost always mistaken for colonic diverticulitis. It is caused by torsion or venous thrombosis of an epiploic appendage (1-4). The sigmoid colon in the left iliac fossa is the most common location. Epiploic appendagitis is more common than generally assumed. Between 3% and 7% of patients suspected of having diverticulitis actually have epiploic appendagitis (4,5).
Patients usually present with acute or subacute left lower quadrant pain suggestive of diverticulitis. Infarcted appendages of the right colon may mimic cholecystitis or appendicitis. Patients have localised tenderness of a small area due to the adherence of the appendage to the parietal peritoneum. Coughing, deep breathing or stretching make the abdominal pain worse (1,5). Laboratory parameters may show slight elevation of white blood cell count or erythrocyte sedimentation rate.
Sonography typically shows a moderately hyperechoic, ovoid, non-compressible mass adjacent to the colon and at the point of maximum tenderness (1,2). The lesion is frequently adherent to the abdominal wall and may show a hypoechoic rim. The colon usually appears normal. Colour Doppler examination does not reveal any colour flow in the infarcted appendage whereas the altered adjacent tissue frequently shows moderately increased colour flow (3,5).
CT scans also show characteristic findings of an ovoid-shaped fatty lesion surrounded by a hyperattenuating biconvex rim and a central hyperdense line (1,4). Thickening of the parietal peritoneum and perilesional fat stranding is frequently seen.
Both sonography and CT enable the correct diagnosis to be reached. Because epiploic appendagitis is a self-limiting disease, conservative treatment is recommended.
