Pathobiology and molecular profiling of peripheral T-cell lymphomas.
Peripheral T-cell lymphomas (PTCLs) are a heterogeneous group of rare diseases, usually manifesting clinical aggressiveness. Although important novel insights into the pathobiology of nodal PTCL have been gained recently from molecular profiling studies and clinico-pathological analyses, the pathogenetic molecular lesions remain to be deciphered for most entities. Angioimmunoblastic T-cell lymphoma (AITL) comprises CD4+ CXCL13+ neoplastic cells displaying overlapping immunophenotypical and molecular features with normal follicular helper T cells. This derivation might account for the presence of a prominent non-neoplastic component in AITL tissues and the clinical manifestations of the disease reflective of an immunological dysfunction. ALK+ anaplastic large cell lymphoma (ALCL), defined by ALK gene translocation with various gene partners, is composed of CD30+ ALK+ cells with a cytotoxic phenotype and usually carries a good prognosis. ALK- ALCL, now considered as a distinct disease entity, is morphologically and immunophenotypically similar to ALK+ ALCL, except for ALK expression, but has distinctive molecular features. PTCL, not otherwise specified (PTCL, NOS), the largest PTCL category, which is derived from activated CD4+ (or CD8+) T cells, is markedly heterogeneous, including at the molecular level. Gene expression profiling approaches have identified novel biomarkers of potential therapeutic interest, and suggest the existence of molecularly distinct PTCL, NOS subgroups.
de Leval
Laurence
L
Pathology Department, University of Liège, CHU Sart Tilman, Liège, Belgium. L.deLeval@ulg.ac.be
Gaulard
Philippe
P
D001402:B-Lymphocytes / Q000473:pathology; D020869:Gene Expression Profiling; D015321:Gene Rearrangement; D019672:Genes, T-Cell Receptor; D014644:Genetic Variation; D019337:Hematologic Neoplasms / Q000145:classification; D006801:Humans; D007119:Immunoblastic Lymphadenopathy / Q000145:classification / Q000473:pathology; D016393:Lymphoma, B-Cell / Q000145:classification; D017728:Lymphoma, Large-Cell, Anaplastic / Q000235:genetics / Q000473:pathology; D016411:Lymphoma, T-Cell, Peripheral / Q000145:classification / Q000235:genetics* / Q000473:pathology*; D008875:Middle Aged; D016539:Reed-Sternberg Cells / Q000473:pathology; D006377:T-Lymphocytes, Helper-Inducer / Q000473:pathology