Abstract
Gossypiboma refers to a mass resulting from a retained gauze pad accidentally left within the body after surgery. Although the clinical features are diverse, it is often found incidentally as a mass having an internal cystic change and adhesion to adjacent organs. Abdominal computed tomography (CT) is helpful, yet the initial diagnosis can be misleading in cases with atypical findings. We report a case of gossypiboma in a 78-year-old woman that we suspected was a gastrointestinal stromal tumor according to abdominal CT and endoscopic ultrasound, yet was diagnosed as a gossypiboma postoperatively.