Retained surgical foreign body on CT

A 75-year-old male presents with a palpable mass in the left hemiabdomen. He had abdominal surgery six years prior following a motor vehicle accident. A CT scan through the abdomen (A) shows a large cystic mass associated with a hyperattenuating foreign body (arrow) consistent with a gossypiboma. Image B shows the inferior extent of the mass. The mass was resected and pathology showed sponge-like foreign material with associated xanthogranulomatous inflammation.