title: Pathobiology of T-cell and NK-cell lymphomas.
abstract: T-cell and NK-cell lymphomas are uncommon lymphomas with an aggressive clinical course. The causes and precise cellular origins of most T-cell lymphomas are still not well defined. The WHO classification utilizes morphologic and immunophenotypic features in conjunction with clinical aspects and in some instances genetics to delineate a prognostically and therapeutically meaningful categorization. The anatomic localization of neoplastic T-cells and NK-cells parallels in part their proposed normal cellular counterparts and functions. T-cells of the adaptive immune system are mainly based in lymph nodes and peripheral blood, whereas lymphomas derived from T-cells and NK-cells of the innate immune system are mainly extranodal. This approach allows for better understanding of some of the manifestations of the T-cell and NK-cell lymphomas, including their cellular distribution, some aspects of morphology and even associated clinical findings.
authors.affiliation: Laboratory of Pathology, National Cancer Institute, Building 10, Room 2N113, Bethesda, MD 20892, USA. ewa.bajor-dattilo@nih.gov
authors.forename: Ewa B
authors.initials: EB
authors.lastname: Bajor-Dattilo
authors.forename: Stefania
authors.initials: S
authors.lastname: Pittaluga
authors.forename: Elaine S
authors.initials: ES
authors.lastname: Jaffe
mesh_terms: D056704:Adaptive Immunity; D006801:Humans; D007113:Immunity, Innate; D007694:Killer Cells, Natural / Q000473:pathology*; D008198:Lymph Nodes / Q000276:immunology / Q000473:pathology; D054391:Lymphoma, Extranodal NK-T-Cell / Q000145:classification / Q000276:immunology / Q000473:pathology*; D016411:Lymphoma, T-Cell, Peripheral / Q000145:classification / Q000276:immunology / Q000473:pathology*; D055611:Natural Killer T-Cells / Q000276:immunology / Q000473:pathology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology / Q000473:pathology*