Idiopathic Isolated Omental Panniculitis Confirmed by Percutaneous CT-Guided Biopsy

Abstract

The preoperative diagnosis of intraabdominal panniculitis is difficult due to its rarity. However, the increased use of abdominal computed tomography (CT) for a variety of indications has increased the diagnosis of intraabdominal panniculitis, including omental panniculitis. The characteristic CT features of intraabdominal panniculitis are increased attenuation of the adipose tissue, the fat-ring sign, a tumoral pseudocapsule, soft-tissue nodules, and a left-sided orientation of mass maximum transverse diameter. Recognition of these features is valuable in the diagnosis of panniculitis, and hence percutaneous CT-guided biopsy to determine their presence may prevent unwarranted surgery. We report the case of a 61-year-old man found to have an idiopathic isolated omental panniculitis that was diagnosed by abdominal CT and percutaneous CT-guided biopsy.

Keywords: Panniculitis; Peritoneal; Tomography, X-ray computed.

Fig. 1

Contrast-enhanced abdominal computed tomography (CT) showing two heterogeneous mixed low- and high-attenuation masses (open arrows) in the omentum around the transverse colon. The fat-ring sign (arrow), which is the omental fat surrounding the omental vessels, is noted. A tumoral pseudocapsule (arrowheads) is also evident as anterior and posterior thin hyperdense rims surrounding the omental mass.

Fig. 2

Microscopic findings. Aggregates of foamy macrophages and infiltrates of chronic inflammatory cells are present. Fibrosis is also evident (A, H&E stain, ×200; B, H&E stain, ×200).

Fig. 3

Follow up contrast-enhanced abdominal computed tomography (CT) showing markedly reduced omental masses (open arrows) as compared with the original, posttreatment CT.