T-Cell Large Granular Lymphocytic Leukemia Presenting as Isolated Transfusion-Dependent Anemia Without Autoimmune Disease: A Case Report.

Large granular lymphocytic (LGL) leukemia is a rare lymphoproliferative disorder characterized by cytopenia and autoimmune manifestations. While cytopenia and rheumatoid arthritis (RA) are common, transfusion-dependent anemia (TDA) without RA or other autoimmune disease is less frequently observed. We present a 79-year-old male with T-cell LGL leukemia, exhibiting isolated TDA without an autoimmune disease. Anemia remained refractory to erythropoietin and methotrexate, requiring transfusions, but showed a response to cyclophosphamide after 3 months of therapy. This case highlights an uncommon presentation of LGL leukemia, emphasizing the importance of considering LGL leukemia in the differential diagnosis of TDA.