Plasmablastic Lymphomas of the Oral Cavity: A New Entity Associated With the Human Immunodeficiency Virus Infection

Abstract

We report here a series of 16 highly malignant diffuse large B-cell lymphomas of the oral cavity with unique immunohistologic features. Fifteen of these developed in human immunodeficiency virus-positive patients. All cases displayed morphologic features of diffuse large-cell lymphomas but strikingly differed from them in that they showed a minimal or absent expression of the leukocyte common antigen as well as of the B-cell antigen CD20. Instead, the tumor cells showed a constant reaction with the plasma cell characteristic antibody VS38c and a frequent reaction with the CD79a antibody. This, in conjunction with a variable expression of cytoplasmic Ig and a monoclonal rearrangement of the Ig heavy chain gene in all of the three tested cases confirmed the B-cell nature, the clonal origin, and the plasmacellular differentiation of these neoplasms. The majority of these tumors were negative for the BCL-6 protein, with the remaining cases showing only a partial and weak expression of this antigen. An association with the Epstein-Barr virus (EBV) was found in 9 of 15 tested cases showing abundant EBV-encoded nuclear RNA transcripts in the absence of EBNA-2. Five of the EBV-positive cases variably expressed LMP-1. We propose to name these tumors plasmablastic lymphomas, in accordance with their morphologic and immunohistologic features. Knowledge of this lymphoma entity is important to avoid confusion with nonlymphoid malignancies due to the lack of commonly used lymphoid markers.

Fine needle aspiration cytology of lymphoproliferative lesions of the oral cavity

“…Moreover, certain specific entities, such as plasmablastic lymphoma, an acquired immunodeficiency syndrome (AIDS)-associated high-grade NHL, 20,21 have a high incidence in the oral cavity. 21,28,29 Finally, benign entities, such as plasmacellular granuloma 30 and FRLH, 31 may arise in the oral cavity, further widening the spectrum of lymphoid oral swellings or masses.…”

AIDS‐related lymphomas: from pathogenesis to pathology

“…The histological appearance of PBL is monomorphic, with a diffuse and cohesive growth pattern of large neoplastic cells that have a 'squared-off' appearance. The lymphoma cells have abundant cytoplasm and eccentrically placed nuclei with a single prominent nucleolus (Delecluse et al, 1997;Carbone et al, 1999;Knowles & Pirog, 2001;Raphael et al, 2001;Carbone, 2002). Their immunophenotype is characterised by a weak or absent expression of the most commonly used lymphoid markers.…”

Aggressive B‐cell lymphomas: a review based on the workshop of the XI Meeting of the European Association for Haematopathology

“…38,39 Plasmablastic lymphoma The WHO classification currently lists plasmablastic lymphoma as a rare variant of DLBCL presenting in the oral cavity in the setting of HIV infection, frequently associated with latent EBV infection (60%) and often lacking expression of CD20 and CD45. 40 Distinction from poorly differentiated myeloma may be problematic, but clinical findings and serum protein studies are helpful. Following stimulating discussion at the Workshop, it became apparent that definitive criteria for the diagnosis of plasmablastic DLBCL should be the subject of further research.…”