Case report 736: Retained surgical sponge (gossypiboma) with a foreign body reaction and remote and organizing hematoma.

This 50-year-old woman presented with progressive pain in the left thigh. Radiographs showed a 9 x 6 cm soft-tissue mass located at the lateral border of the left femur. Magnetic resonance (MR) examination showed an eccentric, nonhomogeneous, soft-tissue mass abutting the femur. The preoperative differential diagnosis was schwannoma, low-grade neurogenic tumor, large periosteal ganglion, or fibroma. At operation, the cut surface of the specimen had features of an organizing hematoma with recent remote hemorrhage and areas of fibrosis. Histopathological examination confirmed the presence of polarizable foreign body material in a background of foreign body reaction. The specimen represented a retained surgical sponge which had been present since the patient's surgery for a comminuted fracture 35 years earlier. Gossypiboma, or cotton balloma, is a term used to describe a mass within the body composed of cotton matrix. Radiopaque markers are now present on surgical sponges, and their appearances have been well documented. The gossypiboma, however, may still present a diagnostic problem if the marker is distorted by folding, twisting, or disintegration over a period of time. Without the radiopaque markers, retained sponges are difficult, if not impossible, to diagnose, as was the situation in this case.