Circulating and skin-derived Sézary cells: clonal but with phenotypic plasticity

To the editor: Sezary syndrome (SS) is a rare, aggressive leukemic form of primary cutaneous T-cell lymphoma.[1][1] The diagnostic criteria associate a clonal T-cell receptor (TCR) rearrangement with peripheral Sezary cell (SC) counts of ≥1 G/L, an increased CD4/CD8 ratio of ≥10, CD4+CD7−