Large granular lymphocytic proliferative disorders are a general term for a group of diseases in which there is a persistent increase in peripheral blood large granular lymphocytes without a clear etiology. Clonal large granular lymphocyte proliferative disorders are divided into T-large granular lymphocyte leukemia, chronic NK lymphocyte proliferative disorders, and invasive NK cell leukemia, in which T-large granular lymphocyte leukemia may be associated with HTLV virus, invasive NK cell leukemia may be associated with EBV infection, and chronic NK lymphocyte proliferative disorders are generally negative for EBV. Large granular lymphoid cells (large granular lyphocytes) account for approximately 10-15% of normal human peripheral blood mononuclear cells, most of which (85%) are derived from CD3(-) NK cells and a small proportion (15%) from CD3(+) T cells. T-large granular lymphocytic leukemia generally has an inert clinical course with a survival period of up to 10 years or more. Patients with T-large granular lymphocytic leukemia are prone to cytopenias, recurrent bacterial infections, autoimmune diseases or/and splenomegaly, recurrent infections etiology associated with neutropenia, initially occurring in 20-40% of patients. It is also the predominant cause of pure red cataracts. Invasive NK-cell leukemia has an acute onset, with a median age of onset around 40 years old and a male to female ratio of 1:1. There is often unexplained hyperthermia and marked enlargement of the liver and spleen, with a 91% incidence of splenomegaly, 64% of hepatomegaly, 27% of lymph node enlargement, and often gastrointestinal symptoms with jaundice and ascites. Jejunal perforation and central nervous system infiltration have also been reported. Clinical manifestations: anemia and thrombocytopenia are common and severe, absolute lymphocyte values are increased, and LGL cells are increased. Bone marrow picture: myeloid cell maturation arrest and lymphocytic infiltration. Immunophenotype: CD3-,CD4-,CD8-,CD16+,CD56+,CD57-/+. In addition, there are coagulation abnormalities. Pathological features: the bone marrow shows a diffuse lymphocytic infiltrate, which may have nodule formation, due to reactive B lymphocyte aggregation, while the extra-nodular interstitial area is infiltrated with leukemia, and some patients have fibrosis. Its treatment is based on combination chemotherapy with regimens CHOP, COP, SMILE, etc., but the efficacy is poor and death often occurs within 1-2 months after diagnosis.