Extracardiac Mass After Pericardiectomy: Mediastinal Fat Replacement Secondary to Progressive Constrictive Pericarditis.

We describe an extracardiac mass in a 72-year-old man with a history of pericardiectomy for constrictive pericarditis. Imaging studies revealed that progressive shrinkage of the residual pericardium compressed mitral valve anteriority, and fat replacement of the secondarily enlarged posterior space of the atrioventricular groove appeared as a space-occupying lesion. (Level of Difficulty: Intermediate.).