Multiparameter flow cytometry in the differential diagnosis of aberrant T-cell clones of unclear significance

Abstract

Immunophenotypic distinction between neoplastic and reactive T-cell clones can be challenging, as peripheral T-cell lymphomas (PTCLs) lack an immunophenotypic marker of clonality. Systematic screening of 10 510 cases analyzed by immunophenotyping at our institution between 2006 and 2012 resulted in 49 cases with aberrant T-cell populations of unclear significance. Review of patient charts allowed us to assign these cases to three categories. In 21 cases, PTCL could later be confirmed by complementary diagnostics (PTCL group). In 20 cases, follow-up confirmed the reactive nature of the aberrant T-cells (non-PTCL group). Eight cases remained of unclear significance. Neither the population size nor the number of aberrant markers differed significantly between the PTCL and non-PTCL groups. Only loss of CD7 was found significantly more often in patients with PTCL than in patients with non-PTCL (p = 0.037). Our data show that aberrant T-cell populations need to be interpreted in the clinicopathological context, as reactive and neoplastic phenotypes largely overlap.

Keywords::

• Multiparameter flow cytometry
• peripheral T-cell lymphoma
• immunophenotyping
• reactive T-cells

Potential conflict of interest

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Supplementary material available online

Supplementary Table I showing mean fluorescence intensity of T-cell antigens available online at http://informahealthcare.com/doi/abs/10.3109/10428194.2014.926347.