CT features of a pericardial gossypiboma

We report a case of surgically retained pericardial sponge as a cause of pa racardiac mass in a woman who had thoracotomy 3 weeks prior for replacement of mitral valve prosthesis. Computed tomography examination showed a thin- walled mass containing relatively high-density material in the central part with low-density rim at the periphery suggesting a haematoma with clot for mation at first. Surgically removed mass was a retained sponge between righ t atrium and pericardium. Gossypiboma should be included in the differentia l diagnosis of an intrathoracic mass besides haematoma and abscess formatio n in any patient who has had previous thoracotomy.