Rare Coexistence of Myelodysplastic Neoplasm and CD4 T-cell Lymphoproliferation

BACKGROUND: Myelodysplastic neoplasms (MDS) are characterized by cytopenia and morphologic dysplasia in myeloid cells and are considered a disease of the myeloid lineage. MDS with concurrent lymphoid clonality is rare and mostly occurs in CD8 T-cells. METHODS: We evaluated a 74-year-old man who presented with anemia and lymphocytosis using peripheral blood immunophenotyping, bone marrow examination, and next-generation sequencing. RESULTS: The patient was diagnosed with MDS with low blasts and an SF3B1 mutation (MDS-SF3B1), concurrent with clonal CD4 T-cell lymphoproliferative disorder, supported by TCR gene rearrangement and distinct mutation profiles. CONCLUSIONS: This is the first reported case of MDS-SF3B1 coexisting with clonal CD4 T-cell proliferation.