Kaposi sarcoma herpesvirus/human herpesvirus-8-negative effusion-based lymphoma: report of 3 cases and review of the literature.

Primary effusion lymphoma (PEL) is a rare subtype of large B-cell lymphoma that arises in body cavities without detectable tumor masses. PEL is universally associated with Kaposi sarcoma herpesvirus (KSHV)/human herpesvirus-8 (HHV8). Despite overlapping features, KSHV/HHV8-negative effusion-based lymphoma is a distinct entity from PEL. To date, 52 cases have been reported. The authors report 3 additional cases received in their laboratory from 2007 to 2012. Clinical data, cytomorphologic features, and immunophenotypic features of the 3 cases were described and compared with those reported in the literature. The cells in HHV8-negative effusion lymphoma commonly revealed large cell, immunoblastic morphology and B-cell immunophenotype. The 3 cases demonstrated cytomorphologic and immunophenotypic variability. Cytomorphologically, 1 case contained large, highly atypical cells with a moderate amount of cytoplasm, round nucleus, coarsely granular chromatin, and a single macronucleolus. The other 2 cases had medium to large atypical cells with high nuclear-to-cytoplasmic ratios, slightly irregular to cleaved nuclei, and multiple conspicuous nucleoli. One case had a null phenotype with aberrant cytokeratin expression. B-cell phenotype was established by clonal immunoglobulin heavy-chain rearrangement using polymerase chain reaction, whereas the other 2 cases demonstrated a B-cell phenotype by flow cytometry and immunohistochemical staining. All 3 cases were negative for both HHV8 and Epstein-Barr virus. HHV8-negative effusion lymphoma exhibits clinical, cytomorphologic, and immunophenotypic variability. Cases with a null-phenotype can be particularly challenging. When effusion lymphoma is suspected, ancillary tests are helpful. Moreover, HHV8 detection is critical in differentiating PEL and HHV8-negative effusion lymphoma, because they have overlapping features yet different prognoses.

Xiao J ，Selvaggi SM ，Leith CP ，Fitzgerald SA ，Stewart J 3rd ... -  《-》

Extracavitary KSHV-associated large B-Cell lymphoma: a distinct entity or a subtype of primary effusion lymphoma? Study of 9 cases and review of an additional 43 cases.

Pan ZG ，Zhang QY ，Lu ZB ，Quinto T ，Rozenvald IB ，Liu LT ，Wilson D ，Reddy V ，Huang Q ，Wang HY ，Ren YS ... -  《-》

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.

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. 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. 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.

Zhang H ，Yang XY ，Hong T ，Feldman T ，Bhattacharyya PK ... -  《-》

KSHV/HHV8-negative effusion-based lymphoma, a distinct entity associated with fluid overload states.

Alexanian S ，Said J ，Lones M ，Pullarkat ST ... -  《-》

KHSV(-) EBV(-) post-transplant effusion lymphoma with plasmablastic features: variant of primary effusion lymphoma?

Primary effusion lymphoma (PEL) is a rare type of B-cell non-Hodgkin lymphoma (NHL), which predominantly occurs in HIV-infected individuals, and is pathogenetically linked with Kaposi sarcoma (KS)-associated herpes virus/human herpes virus-8 (KSHV/HHV-8) infection with or without evidence of Epstein-Barr virus (EBV) co-infection. Although uncommon, PELs have been reported in immunocompetent patients and recipients of solid organ allografts. Rare cases of KSHV(-) EBV(+) post-transplant effusion lymphomas resembling PEL have also been described, as have KSHV(-) EBV(-) effusion lymphomas, the latter including those arising in individuals with chronic liver disease. We report a unique KSHV(-) EBV(-) post-transplant effusion lymphoma associated with serum paraproteins, occurring in an HIV(-) individual, which had cytologic features and phenotype similar to PEL, and displayed a complex karyotype including isochromosome 12p and translocation t(8;22), resulting in rearrangement of c-MYC.

Lambe JS ，Oble DA ，Nandula SV ，Sevilla DW ，Colovai AI ，Mansukhani M ，Chari A ，Murty VV ，Alobeid B ，Bhagat G ... -  《-》