Presentation
Routine investigation for the cause of anemia.
Patient Data
The initial CT study illustrates a well-defined 4.1 cm fat-containing ovoid mass with a thick capsule and dystrophic mural calcification in the upper abdomen.
The follow-up CT (5 months later) demonstrates the lesion to have moved within the peritoneal cavity having moved to the pelvis, its mobile nature representing an important feature for diagnostic purposes.
Case Discussion
There are few reported cases of giant peritoneal loose bodies. They may present symptomatically as intestinal obstruction but are usually incidental findings on CT studies of the abdomen or found during routine exploration of the abdomen for another pathology.
The precise pathogenesis of loose bodies is not completely understood, however the current theory is that it occurs following torsion of an epiploic appendage, and later by ischemia, saponification and calcification. Atrophy of the pedicle allows detachment from the colonic surface to become a loose body.
Peritoneal loose bodies have common key imaging features with some characteristic variants. This case highlights the characteristic diagnostic features. Imaging differentials include other abdominal benign lesions with calcification, such as tuberculosis or granuloma.