Myelodysplastic syndromes with ring sideroblasts ( <scp>MDS‐RS</scp> ) and <scp>MDS</scp> /myeloproliferative neoplasm with <scp>RS</scp> and thrombocytosis ( <scp>MDS/MPN‐RS‐T</scp> ) – “ <scp>2021</scp> update on diagnosis, risk‐stratification, and management”

Disease Overview Ring sideroblasts (RS) are erythroid precursors with abnormal perinuclear mitochondrial iron accumulation. Two myeloid neoplasms defined by the presence of RS, include myelodysplastic syndromes RS (MDS-RS) and MDS/myeloproliferative neoplasm thrombocytosis (MDS/MPN-RS-T). Diagnosis MDS-RS is a lower risk MDS, single or multilineage dysplasia (MDS-RS-SLD/MLD), <5% bone marrow (BM) blasts, <1% peripheral blood blasts ≥15% BM (≥5% in SF3B1 mutations). MDS/MPN-RS-T, now formal entity MDS/MPN overlap syndromes, has diagnostic features MDS-RS-SLD, along platelet count ≥450 × 109/L large atypical megakaryocytes. Mutations Karyotype seen ≥80% patients MDS-RS-SLD strongly correlate RS; MDS/MPN-RS-T also demonstrate JAK2V617F (50%), DNMT3A, TET2 ASXL1 mutations. Cytogenetic abnormalities uncommon both. Risk Stratification Most stratified into groups revised-IPSS. outcome better than that but worse essential thrombocythemia (MPN). Both diseases associated low leukemic transformation. Treatment Anemia overload complications both managed similar to MDS MPN. Luspatercept, first-in-class maturation agent approved for management anemia MDS/MPN-RS-T. Aspirin therapy reasonable especially JAK2V617F, value platelet-lowering drugs remains be defined.