T-Cell Large Granular Lymphocyte Leukemia

T-cell large granular lymphocyte leukemia is a rare cancer of a type of white blood cells called lymphocytes. T-cell large granular lymphocyte leukemia causes a slow increase in white blood cells called T lymphocytes, or T cells, which originate in the lymph system and bone marrow and help to fight infection. This disease usually affects people in their sixties. Symptoms include anemia; low levels of platelets (thrombocytopenia) and infection-fighting neutrophils (neutropenia) in the blood; and an enlarged spleen. About one-third of patients are asymptomatic at the time of diagnosis. The exact cause of LGL leukemia is unknown. Doctors can diagnose this disease through a bone marrow biopsy, or by using a specialized technique in which various types of blood or bone marrow cells are separated, identified, and counted.