Clonal proliferation of T-Cell large granular lymphocytes

T-cell large granular lymphocyte (T-LGL) leukemia is a disorder only rarely reported in children. We diagnosed a new case of a clonal T-LGL proliferation in a 6-year-old girl presenting with severe neutropenia and pure red blood cell aplasia (PRCA).

Flow cytometric analysis including TCR-Vbeta repertoire analysis and molecular studies using reverse transcriptase polymerase chain reaction (RT-PCR), PCR heteroduplex analysis and GeneScan analysis were performed to investigate the clonal nature of the T-LGL.

Flow cytometric analysis revealed a Vbeta3 clonal nature. Molecular studies identified a clonal Vbeta3-Cbeta RT-PCR product. Both PCR heteroduplex analysis and GeneScan analysis found clonal TCRB and TCRG gene rearrangements.

An underlying T-LGL leukemia should be investigated in the diagnostic evaluation of acquired PRCA and neutropenia in young children. Both flow cytometric and molecular analyses can be used to establish the clonal nature of T-LGL.