Abstract 16992: Superior Vena Cava Syndrome in a Patient With Metastatic Primary Cardiac Diffuse Large B-cell Lymphoma - Case Report

Abstract

Introduction: Primary cardiac tumors are uncommon, with an estimated incidence of 0.02%. Primary cardiac lymphomas (PCL), a subtype of non-Hodgkin lymphoma, account for about 10% of malignant and 1% of all primary cardiac tumors. Diffuse large B-cell lymphomas (DLBCLs) emerge as the predominant histological subtype within PCL cases. Case presentation: 54-year-old White male with no medical history presented with a few weeks of exertional dyspnea, nonproductive cough, and neck fullness. Exam was notable for tachycardia, jugular venous distension, bilateral upper extremity edema, and distended chest wall vasculature. Labs showed elevation of alkaline phosphatase and CRP. CT of the chest showed a right atrial mass extending into and obstructing the superior vena cava (SVC) and mediastinal lymphadenopathy (Panel A & B). Coronary CTA performed a few years earlier showed normal interatrial septum (Panel C) and coronary arteries. Transthoracic echo (TTE) confirmed a 7.6 x 5.0cm mass visualized in the interatrial septum extending to both atria. Cardiac MRI redemonstrated a large cardiac mass with malignant features suggestive of cardiac lymphoma vs angiosarcoma (Panel D-F). PET-CT showed enhanced fluorodeoxyglucose (FDG) uptake within cardiac mass, mediastinal, and intraabdominal lymph nodes (Panel G). Lymph node biopsy confirmed DLBCL. Patient underwent three cycles of EPOCH (etoposide phosphate, prednisone, vincristine sulfate, cyclophosphamide, doxorubicin hydrochloride) chemotherapy with excellent response. TTE following cycle 2 demonstrated decreased tumor size, and PET-CT after cycle 3 confirmed complete resolution of lymphadenopathy and minimal residual intracardiac FDG uptake. Conclusion: SVC syndrome can be a rare presentation of PCL. Multimodality imaging is important in cardiac mass characterization, diagnosis, treatment planning, and follow-up. Timely diagnosis and initiation of chemotherapy results in improved outcomes.