Plasmablastic Lymphoma: A Review of Current Knowledge and Future Directions

Abstract

Plasmablastic lymphoma (PBL) is an aggressive subtype of non-Hodgkin's lymphoma (NHL), which frequently arises in the oral cavity of human immunodeficiency virus (HIV) infected patients. PBL shows diffuse proliferation of large neoplastic cells resembling B-immunoblasts/plasmablasts, or with plasmacytic features and an immunophenotype of plasma cells. PBL remains a diagnostic challenge due to its peculiar morphology and an immunohistochemical profile similar to plasma cell myeloma (PCM). PBL is also a therapeutic challenge with a clinical course characterized by a high rate of relapse and death. There is no standard chemotherapy protocol for treatment of PBL. Cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) or CHOP-like regimens have been the backbone while more intensive regimens such as cyclophosphamide, vincristine, doxorubicin, high-dose methotrexate/ifosfamide, etoposide, high-dose cytarabine (CODOX-M/IVAC), or dose-adjusted etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin (DA-EPOCH) are possible options. Recently, a few studies have reported the potential value of the proteasome inhibitor bortezomib and thalidomide in PBL patients. The introduction of genes encoding artificial receptors called chimeric antigen receptors (CARs) and CAR-modified T cells targeted to the B cell-specific CD19 antigen have demonstrated promising results in multiple early clinical trials. The aim of this paper is to review the recent advances in epidemiology; pathophysiology; clinical, pathologic, and molecular characteristics; therapy; and outcome in patients with PBL.

Figure 1

Histopathologic features of PBL: (a) H&E stain shows sheets of large atypical lymphoid cells with plasmacytic differentiation with abundant cytoplasm, paranuclear hof, and large nuclei; (b) it displays large cells with an immunoblastic appearance, with central oval nuclei with prominent nucleoli and moderately abundant cytoplasm.

Figure 2

Selected immunophenotype of PBL: the PBL cells demonstrate immunoreactivity to CD138 (a), lambda light chain, ISH (b), and HHV8 (c) and negativity for CD20 (d) and CD56 (e). Proliferation index is high (f).