Uncommon Variant of CD4+ T-cell Large Granular Lymphocytic Leukemia

Abstract

Abstract Introduction/Objective T-cell large granular lymphocytic leukemia (T-LGL) is a T-cell lymphoma with persistently increased large granular lymphocytes in peripheral blood. The majority of T-LGL is associated with CD8+ T-cells. However, the CD4+ variant is uncommonly seen. Methods/Case Report The patient is a 49-year-old female with a history of diabetes mellites and anemia who presented with shortness of breath, lower extremities edema, and fatigue. Physical examination showed a significantly distended abdomen. CBC results showed hemoglobin 6.9 g/dL, WBC 18.2 × 109/L with 88% lymphocytes, and PLT 190,000. The peripheral blood smear presented lymphocytosis with LGL cells, microcytic anemia, and increased target cells. Bone marrow biopsy showed lymphoid infiltrate as an intravascular pattern confirmed by immunochemical stains. A complete workup including flow cytometric, cytogenetics, and molecular studies was performed on the bone marrow. The lymphoma phenotype by flow shows positivity for CD2, CD3, CD4, CD5 (bright), CD7 (partial/dim), CD56, CD57 (majority), TCRαβ. T-cell gene rearrangement was detected and was further confirmed by PCR with the detection of clonal TCR beta gene rearrangements on molecular genetics analysis. However, STAT3 was not detected. The patient was diagnosed with CD4+ T-LGL leukemia. Results (if a Case Study enter NA) NA. Conclusion CD4+CD8- immunophenotype is an uncommon variant of T-LGL, which has a high incidence of activating STAT5B mutation, while CD8+CD4- T-LGLL tends to have STAT3 mutation. Clinically, those two subtypes behave similarly. Flow cytometry is the golden method to confirm the diagnosis. More research is needed to clarify the essence of CD4+ T-LGLL.