Myelodysplastic neoplasms (MDS) are a group of clonal hematopoietic stem cell neoplasms characterized by peripheral blood cytopenia (due to ineffective hematopoiesis and apoptosis of cells earlier than normal), dysplasia in one or more myeloid cell lines, and an increased risk of developing acute myeloid leukemia.
MDS falls into two main categories: de novo cases with no previous exposure to cytotoxic agents (primary MDS) and secondary cases related to prior chemotherapy or radiation therapy.
