ABSTRACT
T-large granular lymphocyte leukemia (T-LGLL) is characterized by persistent (>6 months) lymphocytosis in blood (≥2 × 109/L) and lymphoid cells with abundant cytoplasm and azurophilic (MPO-negative) granules [1–4]. Two main variants of LGL proliferations can be recognized: T-cell LGLL and chronic lymphoproliferative disorder of NK-cells (CLPD-NK), which account for more than 85 and 10% of cases, respectively. Another rare variant of LGL proliferation is called aggressive NK-cell leukemia, which is associated with Epstein-Barr virus (EBV) infection and poor prognosis. Rare cases with mixed-phenotype (T-LGLL/CLPD-NK phenotype or αβ/γδ phenotype) have been reported [5].
