Isolated right heart purulent pericarditis forming a large mediastinal mass.

A 40-year-old man developed cardiomegaly with protrusion of the right heart border following staphylococcal endocarditis. Computed tomography of the chest revealed a large anterior mediastinal mass. Hemodynamic pressure curves presented features similar to those of constrictive pericarditis. At operation, 150 ml of purulent fluid was encapsulated within the thickened pericardium and separated from the rest of the pericardial sac. The encapsulated abscess was resected.