Issue Highlights – March 2019

Abstract

CHRONIC T AND NK-CELL LYMPHOPROLIFERATIONS Jevremovic and colleagues reviewed the position of flow cytometry in the diagnosis, prognosis and followup of Tand NK-cell lymphoproliferations (1). The diagnosis of these entities is generally based on the demonstration of immunophenotypic abnormalities and demonstration of clonality. The latter studies involve Vbeta T-cell receptor repertoire analysis and killer immunoglobulin like receptors (KIR). In this context it is important to realize that a T-cell clone does not need to be synonymous with “malignancy” but could also reflect the transient clonal proliferation of “reactive” T cells. Among the mature T-cell lymphoproliferative disorders, T-cell large granular lymphocytic leukemia (TLGLL), anaplastic large T-cell lymphoma (ALCL), angioimmunoblastic T-cell lymphoma (AITL), mycosis fungoides or Sezary syndrome (MF/SS), T-cell prolymphocytic leukemia (T-PLL), hepatosplenic T-cell lymphoma (HSTCL) and peripheral T-cell lymphoma, not otherwise specified (PTCL, NOS) are distinguished. Within the NK-cell disorders, chronic lymphoproliferative disorder of NK cells (CLPD-NKs), extranodal NL/ T-cell lymphoma, nasal type, aggressive NL-cell leukemia/lymphoma and NK-cell enteropathy are defined. Nowadays, flow cytometry is a sensitive and specific approach to detect T and NK-cell neoplasms but requires a thorough knowledge of the normal T-cell and NK-cell immune spectrum.