Myelodysplastic Syndrome (MDS) By Ashkan Emadi, MD, PhD, University of Maryland; Jennie York Law, MD, University of Maryland, School of Medicine Reviewed / Revised Jun 2022 | Modified Sep 2022 View Patient Education Pathophysiology Symptoms and Signs Diagnosis Prognosis Treatment Key Points More Information The myelodysplastic syndrome (MDS) is group of clonal hematopoietic stem cell disorders typified by peripheral cytopenia, dysplastic hematopoietic progenitors, a hypercellular or hypocellular bone marrow, and a high risk of conversion to acute myeloid leukemia.