Surviving the Odds: Primary Cardiac Lymphoma With Locoregional Lymph Node Involvement Complicated by Pericardial Effusion and Arrhythmia

Primary cardiac lymphoma (PCL) is a rare malignant disease and its presentation varies depending on the degree of infiltration and location in the myocardium; hence its diagnosis can be challenging. We present a case of a 67-year-old otherwise healthy male who initially presented with recurrent syncope found to have a pericardial effusion and complete heart block. Paratracheal biopsy of a fluorodeoxyglucose (FDG)-avid lymph node was consistent with diffuse large B-cell lymphoma. Diagnosis is usually identified histologically, but imaging is key in guiding biopsy and monitoring disease regression. Chemotherapy is the mainstay of treatment. In this case report, we present a unique presentation of primary cardiac lymphoma presenting as complete heart block with extra-cardiac lymph node involvement and review its management.