Double-Hit High-grade Primary Cardiac Lymphoma (PCL) Presenting as Asymptomatic Tachycardia and Breast Masses in an Immunocompetent female

Introduction:
High-grade B cell lymphomas are rare, aggressive diffuse Large B cell lymphomas (DBCLs) with genetic translocations involving MYC plus BCL2 and/or BCL6 (double or triple hit). Primary Cardiac Lymphomas (PCLs) of this subclass are even more uncommon and may not manifest in the typical pattern associated with other forms of DLBCL.
Results: Case Presentation:
An asymptomatic 52-year-old female presented for health-maintenance visit. EKG revealed sinus tachycardia (130 bpm). Mammogram revealed two, 3cm left breast nodules. Biopsy revealed DLBCL, with double-expressor BCL2/MYC and Ki-67 99%. CT chest/abdomen/pelvis revealed diffuse myocardial tumor infiltration of the LV and IVS (Figure 1), bilateral pleural effusions, and hypodense masses in the pancreas, kidneys, and adrenal glands. Echocardiogram (limited by tachycardia) revealed: EF of 62%. Given poor historical success of standard RCHOP and her abundant tumor burden, DA-R-EPOCH regimen was started. She developed dyspnea. Repeat echocardiogram: severe hypokinesis of the basal to mid-inferior and inferolateral wall (EF 45%). Beta-blockade for sinus tachycardia improved her symptoms. After 6 cycles, there was remarkable cytoreduction of cardiac tumor burden (Figure 2). However, CNS involvement led to debilitating neurological compromise ultimately leading to hospice care.
Discussion:
PCLs account for 0.5% of DBCLs while secondary cardiac involvement is reported in 8.7-25% (most discovered postmortem). PCLs usually present as exophytic masses of the right atrium (77%) associated with dyspnea, chest pain or heart failure in HIV-positive males. To our knowledge this is the first case of a double-hit DBCL with such extensive cardiac involvement presenting as asymptomatic tachycardia and breast masses (0.052 per 100,000) in an immunocompetent female. Furthermore, a diffuse pattern of LV and IVS infiltration has not been frequently described, making this case more unique. We believe that such extensive involvement highly favors an aggressive atypical high-grade PCL with metastasis to 4 rare extra-nodal sites (breast, adrenals, pancreas, kidneys). Early management with beta-blockade was useful in decreasing heart rate and increasing ventricular filling time to improve cardiac function. DA-R-EPOCH produced remarkable cytoreduction. However, this regimen did not prevent CNS involvement. Hence, we recommend research evaluating survival benefits with prophylactic intrathecal chemotherapy plus DA-R-EPOCH to develop more robust management guidelines for high-grade PCLs with a predilection for CNS seeding.