Nodal T-cell lymphomas with a T-follicular helper cell phenotype

The discovery and characterisation of T-follicular helper (TFH) cells, a distinct functional subset of T-helper cells has led to the recognition that some peripheral T-cell lymphomas (PTCLs) have a TFH cell immunophenotype. Due to the overlap in clinical, morphological, immunophenotypic and genetic characteristics, the revised 4^th edition to the WHO classification recognises one umbrella category of ‘angioimmunoblastic T-cell lymphoma and other nodal TCLs of TFH cell origin’. This review provides a brief overview of TFH cells with special emphasis on function and phenotype and a more detailed discussion of clinical, morphologic, immunophenotypic and genotypic characteristics of AITL, follicular T-cell lymphoma and nodal PTCL with TFH phenotype which constitute nodal TCLs of TFH origin. Secondary B-cell proliferations (often EBV positive) and features that help differentiate reactive lymphoid hyperplasia and other types of lymphoma, including PTCL, NOS and secondary B-cell lymphomas and classic Hodgkin lymphoma, from nodal TCLs with a TFH phenotype are discussed.