Primary epiploic appendagitis: US and CT findings

A retrospective review is presented of seven cases of epiploic appendagitis, with surgical confirmation in one case. The main clinico-analytical data and the US and CT findings are described, as well as the histopathologic features in the sole case that underwent surgical resection. We also calculated the frequency of this entity in patients undergoing emergency abdominal US on clinical suspicion of diverticulitis. In all seven cases the clinico-analytical evidence was nonspecific (localized acute abdominal pain and slight leukocytosis), mimicking in six cases the clinical presentation of sigmoid diverticulitis and in one case that of acute appendicitis. US imaging findings were characteristic: a hyperechoic mass localized under the point of maximum pain, adjacent to the anterior peritoneal wall and fixed during deep breathing. In none of the cases did color Doppler US show flow. CT findings were also typical and showed a mass with a peripheral hyperattenuated rim surrounding an area of fatty attenuation. Overall 7.1% of patients investigated to exclude sigmoid diverticulitis finally showed findings of primary epiploic appendagitis. Primary epiploic appendagitis thus shows characteristic US and CT findings that allow its diagnosis and follow-up. This entity is much more frequent than previously reported, especially in patients referred for US to exclude sigmoid diverticulitis.