Mature T-cell lymphomas

Peripheral T-cell lymphomas (PTCLs) represent a heterogeneous group of uncommon malignancies derived from mature T cells characterized by a usually aggressive clinical course. Their clinical presentation, localization and pattern of dissemination, are highly variable. The distinction of PTCL from various reactive conditions, and the diagnosis of PTCL subtypes may be notably challenging. Here, we will present an update on PTCL entities typically manifesting as nodal involvement: angioimmunoblastic T-cell lymphoma, anaplastic large cell lymphomas and peripheral T-cell lymphoma, not otherwise specified. We will review diagnostic criteria, with an emphasis on the appropriate use and interpretation of ancillary studies, discuss the common diagnostic pitfalls and mimicks, including the distinction from other leukaemic and extranodal entities, and address the current issues relevant to pathological classification in the light of recent discoveries and novel molecular insights.