T-LGL leukemia - T-CeIl Large Granular Lymphocytic Leukemia Clinical - Persistent (>6mo) lymphocytosis (2-20k) with proven clonality required for dx - T-cells (usually TCR-AB, rarely GD) - Secondary to sustained immune stimulation - usually in the setting of autoimmune disease - Most present with Neutropenia (85%), anemia (50%), hypergammaglobulinemia; but patients not as pancytopenic/ill as HSTCL - Predominantly leukemic presentation (PB, BM, liver, spleen); no LAD Immunophenotype: - Positive: CD2, CD3, CD8 - Loss of CD5 and/or CD7 - CD57 (80%), CD16 (80%), CD56 is rare - TIA-I, granzyme B, perforin (mature cytotoxic phenotype) - Mostly TCR-AB - Rarely can be CD4+ but this is controversial - Negative for EBER, ALK, TFH, CD25 Genetics: - COO is mature cytotoxic T-cell (AB >>GD) - Karytypte: nonspecific - Missense mutations in STAT3 (40%) rarely STAT5B (mut excl; opposite HSTCL); same in NK version DDx: - chronic LPD of NK cells (provisional): Same morphologic/clinical disease but cells are NK cells (sCD3-, no TCR gene rearrangement). Rx is similar, both are indolent. - Aggressive NK leuk: Make sure to ccheck EBER (+ in ANKL). Dr. Laura Brown @lauraebrown #TLGL #leukemia #TCeIl #LargeGranular #Lymphocytic #Leukemia #hemepath #pathology #diagnosis
