Crossing the Cava: Plasmablastic Lymphoma With Near-Obstructing Tumor Thrombus From a Hepatic Mass Into the Right Atrium

Plasmablastic lymphoma (PBL) is an aggressive B-cell lymphoma associated with human immunodeficiency virus (HIV) infection and Epstein-Barr virus (EBV). It frequently presents extranodally. To our knowledge, PBL involving the liver with contiguous tumor thrombus through the inferior vena cava (IVC) into the right atrium (RA) has not been reported. Plasmablastic lymphoma (PBL) is an aggressive B-cell lymphoma associated with human immunodeficiency virus (HIV) infection and Epstein-Barr virus (EBV). It frequently presents extranodally. To our knowledge, PBL involving the liver with contiguous tumor thrombus through the inferior vena cava (IVC) into the right atrium (RA) has not been reported. A 40-year-old man with newly diagnosed HIV-1 infection and CD4 lymphopenia presented with a pathologic humeral fracture and widespread lytic lesions. Contrast-enhanced computed tomography (CT) showed an 8.8-cm segment VII hepatic mass with contiguous tumor thrombus through the IVC into the RA. Echocardiography showed a 2.9 × 1.4-cm immobile cavoatrial mass almost completely obstructing flow from the IVC into the RA, with preserved biventricular function. Echocardiography could not distinguish tumor from thrombus, but CT demonstrated continuity with the hepatic mass. Liver biopsy showed plasmablastic cells positive for CD138, MUM1, and EBV-encoded RNA and negative for CD20 and PAX5, with MYC rearrangement and a Ki-67 index of 80% to 90%, confirming PBL. Cardiology did not recommend thromboaspiration. Treatment included six cycles of bortezomib plus dose-adjusted EPOCH (etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin), antiretroviral therapy, and anticoagulation. Follow-up CT at four months showed no residual hepatic or caval disease. Subsequent positron emission tomography/computed tomography showed progressive osseous and thoracic disease. He received palliative radiation and four cycles of daratumumab plus ICE (ifosfamide, carboplatin, and etoposide), followed by autologous stem cell transplantation after BEAM conditioning (carmustine, etoposide, cytarabine, and melphalan). A 40-year-old man with newly diagnosed HIV-1 infection and CD4 lymphopenia presented with a pathologic humeral fracture and widespread lytic lesions. Contrast-enhanced computed tomography (CT) showed an 8.8-cm segment VII hepatic mass with contiguous tumor thrombus through the IVC into the RA. Echocardiography showed a 2.9 × 1.4-cm immobile cavoatrial mass almost completely obstructing flow from the IVC into the RA, with preserved biventricular function. Echocardiography could not distinguish tumor from thrombus, but CT demonstrated continuity with the hepatic mass. Liver biopsy showed plasmablastic cells positive for CD138, MUM1, and EBV-encoded RNA and negative for CD20 and PAX5, with MYC rearrangement and a Ki-67 index of 80% to 90%, confirming PBL. Cardiology did not recommend thromboaspiration. Treatment included six cycles of bortezomib plus dose-adjusted EPOCH (etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin), antiretroviral therapy, and anticoagulation. Follow-up CT at four months showed no residual hepatic or caval disease. Subsequent positron emission tomography/computed tomography showed progressive osseous and thoracic disease. He received palliative radiation and four cycles of daratumumab plus ICE (ifosfamide, carboplatin, and etoposide), followed by autologous stem cell transplantation after BEAM conditioning (carmustine, etoposide, cytarabine, and melphalan). This case highlights exceptionally rare hepatic-to-cavoatrial PBL extension. CT demonstrated continuity with the hepatic mass when echocardiography could not distinguish tumor from thrombus. Anticoagulation does not treat intravascular lymphoma, and cavoatrial clearance did not indicate systemic disease control. This case highlights exceptionally rare hepatic-to-cavoatrial PBL extension. CT demonstrated continuity with the hepatic mass when echocardiography could not distinguish tumor from thrombus. Anticoagulation does not treat intravascular lymphoma, and cavoatrial clearance did not indicate systemic disease control.