Uncommon diffuse large B cell lymphoma.
Subtypes of DLBCL with plasmasblastic features and terminal B cell differentiation include: PBL of oral mucosal type, PBL with plasmacytic differentiation, primary effusion lymphoma, extra cavitary primary effusion lymphoma/human herpes-8 (HHV-8) associated DLBCL and anaplastic lymphoma Kinase positive DlBCL.
In contrast to the above plasmablastic lymphoma associated with multicentric Castleman disease, DLBCL with secretory differentiation, and atypical Burkitt lymphoma with plasmacytoid differentiation appear morphologically like plasma cell differentiation but maintain a mature C- cell CD 20 positive phenotype.
Plasmablastic lymphoma is a distinctive B-cell neoplasm with diffuse proliferation of large neoplastic cells, most resembling B-immunoblasts and have immunophenotype of plasma cells and are CD 20 negative.
PBL is thought to originate from a post-germinal center B cell that lacks expression of mature B cell markers, including CD 20, CD 19, and PAX5, while expressing classic plasma cell markers such as CD 38, CD 138, and MUM – 1/IRF –4.
B cell maturation antigen (BCA) is expressed on a majority of PBL specimens.
Plasmablastic lymphoma is associated with HIV infection, Epstein-Barr virus infection, and immunocompromised states.
Most cases associated with HIV infection, but patients can be HIV negative.
Associated with Kaposi’s sarcoma associated virus and occur in high frequency in patients with Castleman’s disease.
Associated in HIV patients with oral and jaw lesions.
Associated with early dissemination and poor response to treatment and poor survival.
Histologically poorly differentiated plasma cells with low or absent B cell markers and strong positive reactions for plasma cells with CD38 and CD138.
Constitutes ≤ 3% of AIDS associated non-Hodgkin lymphomas.
Associated with EBV and HHV-8 infections.
MYC-IgH rearrangement suggest aggressive clinical course.
Tendency to invade bones, abdomen, retroperitoneum, and bone marrow.
Frontline therapy for PBL typically involves anthracycline base chemotherapy such as CHOP or etopside/prednisone/vincristine, cyclophosposphamide (DA-EPOCH): limited value.
BCMA targeting with bispecific antibody therapy such as teclistamab shows evidence of efficacy.