Myelodysplastic Syndrome/Myeloproliferative Neoplasms with Ringed Sideroblasts and Thrombocytosis (MDS/MPN RS-T)–A Case Report with Literature Review on Diagnosis and Management

Myelodysplastic syndrome/Myeloproliferative neoplasms with ringed sideroblasts and thrombocytosis (MDS/MPN RS-T) is a rare disorder with mixed features of dysplasia and myeloproliferation. This is a relatively new independent entity included in the 2016 WHO classification as MDS/MPN with RS-T. The diagnostic criteria include erythroid lineage dysplasia, ≥15% Ringed Sideroblasts (RS), <1% blast cells in peripheral blood, <5% blast cells in the bone marrow, persistent thrombocytosis with platelet count ≥450×109/L, presence of SF3B1 mutation, absence of BCR-ABL1 gene fusion and rearrangement of PDGFRA, PDGFRB or FGFR1 or PCM1-JAK2. In MDS/MPN RS-T, two mutations are commonly seen JAK 2, which promotes myeloid proliferation, and SF3B1 gene, which causes myelodysplasia with ringed sideroblasts commonly observed in this syndrome. We present a relatively young 59-year-old woman diagnosed with MDS/ MPN RS-T based on the above guideline criteria. She has low-risk MDS, which favors a good prognosis; however, the presence of Essential Thrombocythemia (ET) favors a poor prognosis. Currently, there is no consensus on the specific management of this entity, given its rarity. She was referred to an allogeneic hematopoietic stem cell transplant center for curative treatment since she had become transfusion dependent. Before curative treatment, the patient was initiated on ruxolitinib as a bridging therapy to bone marrow transplant.