Localized pericarditis with calcifications mimicking a pericardial tumor.

A 62-year-old man was admitted with increasing palpitations. Radiography of the chest demonstrated a calcified mass. Magnetic resonance imaging revealed compression of the right ventricle by a tumor. At the time of cardiac catheterization, the coronary arteries were found not to supply blood flow of the mass, and no dip-and-plateau pattern was seen in the right ventricular pressure measurements. At the time of surgery, the mass was found to be a focal calcified thickening of the pericardium containing only pus. The thickening resembled an oval pericardial tumor. Microbiologic examination of the pus revealed Propionibacterium acnes.