A rare presentation of Lymphoblastic T cell lymphoma with cardiac tamponade masking restrictive cardiomyopathy

T cell lymphoma involves cardiac structures rarely and tends to be more aggressive. Pericardial effusion is the most common manifestation of cardiac involvement with restrictive cardiomyopathy due to tumor infiltration being extremely rare. The presence of paroxysmal nocturnal dyspnea and orthopnea in a patient presenting with pericardial effusion or tamponade should alert the physician towards possible myocardial disease warranting re-evaluation after pericardiocentesis. We describe a 14-year-old boy with advanced T cell lymphoma presenting with cardiac tamponade. Repeat echocardiography after pericardiocentesis revealed mediastinal mass infiltrating cardiac chambers and great vessels along with features of restrictive cardiomyopathy secondary to tumor infiltration.