Imaging description

A gossypiboma is a retained surgical sponge or swab, derived from gossypium (Latin; cotton) and boma (Swahili; place of concealment) [1]. Sponges are manufactured with various radiopaque markers. The two commonest markers look like a short piece of crumpled radiopaque scotch-tape (Figure 71.1) or a small tangle of wire (Figure 71.2). While these markers are made to be easily seen, in reality they may be obscured by extraneous paraphernalia and poor image quality due to the challenges of x-raying a patient with portable equipment in the operative or early postoperative setting (Figure 71.3). Retained sponges or swabs may also go unrecognized because they are rare and do not “belong” to any of the usual radiology subspecialties, so that many radiologists have limited training in the recognition of gossypibomas. At CT, retained sponges appear as soft-tissue density masses (Figure 71.4), and may show a whorled texture or a “spongiform” pattern with contained gas bubbles [2]. The latter may persist for many months, even when sterile [3]. At MRI, a retained sponge is typically seen as a soft-tissue density mass with a thick well-defined capsule and a whorled internal configuration on T2-weighted imaging (Figure 71.5) [4].

Importance

Radiologically, gossypibomas may go unrecognized or be confused with postoperative collections or tumors. Retained surgical foreign bodies are of major administrative importance because they are regarded as a “never event” by the Center for Medicare and Medicaid Services. The associated medical and liability costs have been estimated at over $200,000 per incident [5].