Myelodysplastic syndrome

Myelodysplastic syndrome or myelodysplastic neoplasm (MDS) is primarily a disease of older adults. It is often diagnosed incidentally in asymptomatic patients. Some patients present with symptoms of anemia, leukopenia, and thrombocytopenia.

Diagnosis is confirmed if blood and bone marrow evaluation reveals cytopenias, morphologic dysplasia, clonal cytogenetic abnormalities or molecular mutations, and blasts (classically <20%).

Treatment is mainly supportive (e.g., blood transfusions, erythropoiesis-stimulating agents). Chemotherapy (e.g., azacitidine, decitabine, lenalidomide) may be used for certain patients. Allogeneic hematopoietic stem cell transplant is the only potentially curative therapy.

Patients may have a prolonged disease course (i.e., with anemia, thrombocytopenia, neutropenia), or may progress rapidly to acute myeloid leukemia (AML). Most deaths occur due to complications from MDS (e.g., infection) before progression to AML.

MDS is a heterogenous group of clonal hematopoietic neoplasms characterized by cytopenias (anemia, neutropenia, and/or thrombocytopenia); significant bone marrow dysplasia; blasts in the peripheral blood and/or bone marrow (classically <20%); cytogenetic/genetic abnormalities (e.g., 5q deletion, SF3B1 mutation, TP53 mutation); and a predilection to progress to AML.[1]Khoury JD, Solary E, Abla O, et al. The 5th edition of the World Health Organization classification of haematolymphoid tumours: myeloid and histiocytic/dendritic neoplasms. Leukemia. 2022 Jul;36(7):1703-19. https://www.doi.org/10.1038/s41375-022-01613-1 http://www.ncbi.nlm.nih.gov/pubmed/35732831?tool=bestpractice.com [2]Arber DA, Orazi A, Hasserjian RP, et al. International Consensus Classification of myeloid neoplasms and acute leukemias: integrating morphologic, clinical, and genomic data. Blood. 2022 Sep 15;140(11):1200-28. https://www.doi.org/10.1182/blood.2022015850 http://www.ncbi.nlm.nih.gov/pubmed/35767897?tool=bestpractice.com  

MDS can arise de novo or occur secondary to antecedent hematologic malignancy or following exposure to chemotherapy or radiation therapy.[3]Steensma DP, Bennett JM. The myelodysplastic syndromes: diagnosis and treatment. Mayo Clin Proc. 2006 Jan;81(1):104-30. http://www.ncbi.nlm.nih.gov/pubmed/16438486?tool=bestpractice.com