Cell size variations of large granular lymphocyte leukemia: Implication of a small cell subtype of granular lymphocyte leukemia with STAT3 mutations

Leuk Res. 2016 Jun:45:8-13. doi: 10.1016/j.leukres.2016.04.001. Epub 2016 Apr 4.

Abstract

Large granular lymphocyte leukemia (LGL-L) has been morphologically defined as a group of lymphoproliferative disorders, including T-cell large granular lymphocytic leukemia (T-LGL-L), chronic lymphoproliferative disorders of NK cells (CLPD-NK) and aggressive NK cell leukemia. We investigated the morphological features of LGL leukemic cells in 26 LGL-L patients in order to elucidate relationships with current classifications and molecular backgrounds. LGL-L cells were mostly indistinguishable from normal LGL. Patients with STAT3 SH2 domain mutations showed significantly smaller cells compared with patients without STAT3 mutations. Four patients with T-LGL-L showed smaller granular lymphocytes with a median diameter of less than 13μm, which were rarely seen in normal subjects. This small subtype of T-LGL-L was recognized among rather young patients and was associated with D661Y mutations in the STAT3 gene SH2 domain. In addition, all of them showed anemia including two cases with pure red cell aplasia. These results suggest the heterogeneity of T-LGL-L and a specific subtype with small variants of T-LGL-L.

Keywords: Cytotoxic T cell; Granular lymphocyte; LGL; Large granular lymphocyte leukemia; STAT3 mutation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Anemia
  • Cell Size*
  • Female
  • Humans
  • Leukemia, Large Granular Lymphocytic / classification
  • Leukemia, Large Granular Lymphocytic / drug therapy
  • Leukemia, Large Granular Lymphocytic / pathology*
  • Male
  • Middle Aged
  • Mutation*
  • STAT3 Transcription Factor / genetics*
  • Young Adult

Substances

  • STAT3 Transcription Factor