title: Peripheral T-cell lymphomas.
abstract: The development of T cells from stem (progenitor) cells to effector cells results from a two-wave process of proliferation and differentiation. The cells of the first differentiation wave are the precursor T cells, and those of the second differentiation wave are peripheral T cells. In the first differentiation wave, resting/circulating naive antigen-reactive T lymphocytes are produced which differ from each other in their antigen receptor-specificity. In the second differentiation wave, those T lymphocytes multiply whose antigen receptors have found the corresponding antigen. Thus three major forms of differentiation can be distinguished in the peripheral T cells: (1) resting/circulating naive antigen-reactive T cells, (2) activated T cells, and (3) effector T cells and memory T cells. In addition, there are at least three major organ-restricted sublines of peripheral T cells, i.e., nodal T cells, mucosa-associated T cells, and skin-associated T cells. Thanks to the availability of markers for most of the above-mentioned T-cell sublines and differentiation forms, all these cellular forms can be associated with certain lymphoma types, i.e., lymphomas of T-cell type can be divided into categories of precursor T-cell lymphomas and peripheral T-cell lymphomas. The peripheral T-cell lymphomas can be subdivided into those derived from lymph nodal, mucosal, and cutaneous T cells. The gut mucosal T-cell lymphomas are associated with enteropathy. The lymph node, mucosal, and cutaneous T-cell lymphomas can be further subdivided into those in which all tumor cells are similar to recirculating resting (nonactivated) T cells, those in which some of the tumor cells resemble activated T cells, and those in which all tumor cells resemble activated T cells.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Institute of Pathology, Steglitz Medical Center, Free University of Berlin, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Stein
authors.forename: D
authors.initials: D
authors.lastname: Dienemann
authors.forename: F
authors.initials: F
authors.lastname: Dallenbach
authors.forename: M
authors.initials: M
authors.lastname: Kruschwitz
mesh_terms: D014408:Biomarkers, Tumor; D002454:Cell Differentiation / Q000502:physiology; D006801:Humans; D008213:Lymphocyte Activation / Q000276:immunology; D016411:Lymphoma, T-Cell, Peripheral / Q000276:immunology / Q000473:pathology*; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D014408:Biomarkers, Tumor