Primary cardiac tumors are rare causes of ventricular arrythmias. This presentation of primary cardiac lymphoma highlights the importance of multimodality cardiac imaging for patients who suffer sudden cardiac arrest. N/A N/A A previously healthy 34 year-old woman suffered an out-of-hospital cardiac arrest. She received bystander CPR and multiple shocks in the field for VT and VF. ECG obtained on arrival showed salvos of monomorphic VT with a LBBB morphology as well as polymorphic VT. Post-arrest ECG demonstrated dynamic changes with evidence of a prolonged QT interval and Brugada type 1 pattern. After stabilization with metoprolol and intravenous lidocaine, cardiac MRI showed an infiltrating mass along the epicardial surface of the right ventricular outflow tract (RVOT). A cardiac CT was subsequently performed for surgical biopsy planning. Biopsy was obtained via hemi-sternotomy; tissue histopathology of the RVOT mass revealed diffuse large B-cell lymphoma. PET and CT scans indicated no evidence of metastatic disease. The patient was diagnosed with primary cardiac lymphoma, and underwent inpatient chemotherapy treatment. A subcutaneous ICD was implanted prior to discharge for secondary prevention. Key images are displayed in Figure 1. This case demonstrates a rare cause of sudden cardiac arrest in a young patient with a new diagnosis of primary cardiac lymphoma. Primary cardiac lymphoma is a very rare disease that accounts for less than 1% of all primary cardiac malignancies, and less than 0.5% of all extra nodal lymphomas. The use of multimodality imaging after a cardiac arrest in this case led to a timely diagnosis and rapid initiation of life saving treatments.