title: Hepatosplenic and other gammadelta T-cell lymphomas.
abstract: The 2005 Society for Hematopathology/European Association for Haematopathology Workshop session 11 was dedicated to hepatosplenic T-cell lymphoma (HSTCL). HSTCL is a rare aggressive type of extranodal lymphoma characterized by hepatosplenomegaly, bone marrow involvement, and peripheral blood cytopenias. HSTCL exhibits a distinctive pattern of infiltration; tumor cells preferentially infiltrate the sinusoids of the splenic red pulp, liver, and bone marrow. The tumor cells have a nonactivated cytotoxic T-cell immunophenotype and frequently carry a recurrent cytogenetic abnormality, isochromosome 7q. Most cases express the gammadelta T-cell receptor, but cases can have an alphabeta phenotype and are considered to be a variant of the disease. Although HSTCL is the prototype peripheral T-cell lymphoma expressing the gammadelta T-cell receptor, non-HSTCL proliferations of gammadelta T cells can involve other extranodal sites, mainly skin and mucosa. These gammadelta T-cell lymphomas display marked heterogeneity in clinical and histologic features. In contrast with HSTCL, non-HSTCL gammadelta T-cell lymphomas frequently have an activated cytotoxic phenotype and most likely are not a single disease entity.
authors.affiliation: Department of Hematopathology, The University of Texas M.D. Anderson Cancer Center, Houston, TX 77030, USA.
authors.forename: Francisco
authors.initials: F
authors.lastname: Vega
authors.forename: L Jeffrey
authors.initials: LJ
authors.lastname: Medeiros
authors.forename: Philippe
authors.initials: P
authors.lastname: Gaulard
mesh_terms: D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping; D008113:Liver Neoplasms / Q000276:immunology / Q000378:metabolism / Q000473:pathology*; D016411:Lymphoma, T-Cell, Peripheral / Q000276:immunology / Q000378:metabolism / Q000473:pathology*; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000378:metabolism*; D013160:Splenic Neoplasms / Q000276:immunology / Q000378:metabolism / Q000473:pathology*; D013601:T-Lymphocytes / Q000378:metabolism / Q000473:pathology*; D014944:World Health Organization
chemical_list: D016692:Receptors, Antigen, T-Cell, gamma-delta