Acute T-cell Lymphoblastic Leukemia Presenting with Cardiac Encasement and Pericardial Tamponade

A 52-year-old woman with a history of breast cancer treated previously with doxorubicin, cyclophosphamide, and radiation therapy presented with subacute onset of dyspnea and tachycardia. She was found to have T cell acute lymphoblastic leukemia (T-ALL) with a mediastinal mass encasing the heart and a large pericardial effusion with tamponade. We highlight how this rare hematologic malignancy may initially present as pericardial tamponade, and specifically discuss presenting symptoms of subacute pericardial tamponade. Further, we discuss presentation, prognosis and management of T-ALL.