Lymphomas occurring specifically in HIV-infected patients: from pathogenesis to pathology.

[primary effusion lymphoma]

Lymphomas that develop in HIV positive patients are predominantly aggressive B-cell malignancies . The most common HIV-associated lymphomas are Burkitt lymphoma (BL ) and diffuse large B-cell lymphoma (DLBCL ). Lymphomas that occur specifically in HIV positive patients include primary effusion lymphoma (PEL ) and its solid variants , plasmablastic lymphoma of the oral cavity type and lymphoma associated with Kaposi sarcoma herpesvirus (KSHV )-related multicentric Castleman disease . These lymphomas , together with BL and immunoblastic lymphoma subtypes with plasmacytoid differentiation , carry Epstein-Barr virus (EBV ) infection and display a phenotype related to plasma cells . Globally , EBV is identified in the neoplastic cells of approximately 40 % of HIV-associated lymphomas , but the detection of EBV varies considerably with the site of presentation and the histological subtype . EBV infection occurs in 80 -100 % of primary central nervous system lymphomas and PELs , 80 % of DLBCLs with immunoblastic-plasmacytoid features , and 30 -50 % of BL-plasmacytoid . KSHV is specifically associated with PEL , which usually occurs in a setting of profound immunosuppression . Current knowledge about HIV-associated lymphomas can be summarized as follows : (1 ) lymphomas specifically occurring in patients with HIV infection are closely linked to other viral diseases ; (2 ) most of these lymphomas exhibit plasmablastic differentiation .