Epidemiology and Pathology of T- and NK-Cell Lymphomas.

[PURPOSE] This review will describe and update readers on the recent changes in the 2017 WHO classification regarding peripheral T-cell lymphomas.

[RECENT FINDINGS] Signficant advances in molecular studies have resulted in revisions to the classification as well as introduction to provisional entities such as breast implant-associated ALCL and nodal PTCL with T-follicular helper phenotype.

[SUMMARY] Major advances in molecular and gene expression profiling has expanded our knowledge of these rare and aggressive diseases.