ABSTRACT
Peripheral T-cell lymphoma (PTCL), not otherwise specified, is a heterogeneous group of tumors with variable clinical features, histology, genetic alteration, response to treatment, and prognosis. It is a mature T-cell lymphoma, which does not fulfill morphologic, phenotypic, or genetic criteria for any distinctive mature T-cell lymphoma category, hence the designation “not otherwise specified” [1–5]. PTCL, although the most common category of peripheral T-cell lymphoproliferative disorders (it accounts for approximately 30% of PTCLs in Western countries), accounts for less than 5–20% of all non-Hodgkin lymphomas [6–8]. PTCL occurs at any age, usually in older patients with the median age of 60 years. It occurs often as a nodal disease, but any other site, including blood, bone marrow (BM), bone, omentum, skin, central nervous system, soft tissues, gastrointestinal tract, spleen, liver, and lung may be involved, often concurrently with lymph node involvement.
