Kaposi Sarcoma-Associated Herpesvirus (Human Herpesvirus Type 8)-Associated Extracavitary Lymphoma: Report of a Case in an HIV-Positive Patient with Simultaneous Kaposi Sarcoma and a Review of the Literature

Background: Kaposi sarcoma-associated herpesvirus (KSHV), or human herpesvirus type 8 (HHV8), is consistently identified in 2 human immunodeficiency virus (HIV)-associated lymphoproliferative disorders: primary effusion lymphoma (PEL) and multicentric Castleman disease. Rarely, KSHV/HHV8-positive extracavitary solid tissue lymphomas occur, often at extranodal sites, which are not associated with an effusion. These solid variants of PEL are similar morphologically, immunophenotypically, clinically and genetically to classic PEL. Case Report: Here we report a case of a 46-year-old HIV-positive patient with lymphadenopathy and Kaposi sarcoma of the skin. The lymph node biopsy shows a KSHV/HHV8-positive high-grade B-cell lymphoma with co-infection with Epstein-Barr virus, which supports the diagnosis of a solid variant of PEL. The same lymph node is also multifocally involved in Kaposi sarcoma. Conclusion: Analysis of viral infection is of primary importance to define this solid variant of PEL. The exact oncogenic mechanisms of HHV8 are not clearly defined. It is believed that it is related to a few latent viral gene products including ORF73, ORF72, and ORF71 which increase proliferation and impair apoptosis through variant regulatory processes. To the best of our knowledge, this is the first reported case of solid tissue PEL along with Kaposi sarcoma involving the same anatomic site. Copyright (C) 2010 S. Karger AG, Basel