Pericardial cyst with partial erosion of the superior vena cava. An unusual case.

A case of pericardial cyst with partial erosion of the superior vena cava occasionally discovered is presented. The involvement of the vein was found on operation and the excision of the cyst was performed without cardiopulmonary bypass, repairing the vena cava by a direct suture. The pathologic examination showed multiple areas of acute and chronic inflammation without signs of infection. This exceedingly rare report indicates that both computed tomography and magnetic resonance are useful to localize the mediastinal mass and to characterize the cystic content. The cardiopulmonary bypass must be available to allow an easy repair of the structures possibly involved particularly in the case of infection.