Aspects moléculaires des lymphomes T périphériques (1)Lymphome T: Lymphome T angio-immunoblastique, lymphome T périphérique non spécifié et lymphome anaplasique à grandes cellules

Peripheral T-cell lymphomas (PTCL) belong to the group of non-Hodgkin lymphoma and particularly that of mature T/NK cells lymphoproliferative neoplasms. The 2008 WHO classification describes different PTCL entities with varying prevalence. With the exception of the histological subtype "ALK positive anaplastic large cell lymphoma", PTCL are characterized by a poor prognosis. The mechanisms underlying the pathogenesis of these lymphomas are not yet fully understood, but development of genomic high-throughput analysis techniques now allows to extensively identify the molecular abnormalities present in tumor cells. This review aims to summarize the current knowledge and recent advances about the molecular events occurring at the origin or during the natural history of main entities of PTCL. It will be published in two parts : the first is focused on the three more frequent entities, angioimmunoblastic T-cell lymphoma, peripheral T-cell lymphoma, not otherwise specified, and anaplastic large cell lymphoma. The second (which will appear in the november issue) will describe other subtypes less frequent and of poor prognosis : extranodal NK/T-cell lymphoma, nasal type, adult T-cell leukemia/lymphoma, and enteropathy-associated T-cell lymphoma. T or NK cell lymphoproliferative disorders with leukemic presentation, primary cutaneous T-cell lymphoma and very rare subtypes of PTCL whose prevalence is less than 5% (hepatosplenic T-cell lymphoma and subcutaneous panniculitis-like T cell lymphoma) will not be discussed herein.