Abstract
Peripheral T-cell lymphoma (PTCL) remains one of the most challenging areas of hematopathology practice. This is partly due to the overall rarity of these neoplasms but also due to the complexity of the underlying biology as well as the marked heterogeneity of their clinical, phenotypic, and genetic features. Recent developments in classification of lymphoid neoplasms, outlined in the Preface to the Mature Lymphoid Proliferations, offer a blueprint for clinical practice and will be used as a template to address this complex area. For ease of use, this chapter is divided into six sections, each addressing distinct thematically related topics. These include (1) nodal follicular TCLs, (2) anaplastic large cell lymphoma, (3) PTCL, not otherwise specified, (4) intestinal and hepatosplenic TCL, (5) Epstein-Barr virus–associated natural killer (NK) and TCLs, and (6) cutaneous TCLs. Mature T-cell and NK-cell neoplasms with primarily leukemic presentation are discussed separately.