Myelodysplastic Syndrome

Myelodysplastic syndrome (MDS) refers to a group of heterogeneous clonal bone marrow disorders characterized by ineffective hematopoiesis, leading to blood cell dysplasia and variable degrees of bone marrow failure. Patients with MDS typically suffer from cytopenias (deficiencies of one or more types of blood cells), which manifest as anemia, infection vulnerability (due to neutropenia), and/or bleeding tendencies (from thrombocytopenia). MDS arises from the malfunction of hematopoietic stem cells, which leads to dysplastic changes in the morphology of blood cells and a heightened risk of progression to acute myeloid leukemia (AML).

The pathophysiology of MDS is complex and involves multiple genetic and epigenetic alterations. These may result from environmental exposures, such as to chemotherapy and radiation, or can occur spontaneously. Diagnosis is made primarily through bone marrow examination, which shows dysplastic features in the marrow cells, often accompanied by cytogenetic abnormalities. MDS is stratified into risk categories based on specific criteria, including blood counts, marrow blast percentage, and genetic abnormalities. This risk stratification guides treatment decisions, which may range from supportive care, such as blood transfusions and growth factors, to disease-modifying therapies like hypomethylating agents, immunosuppressive regimens, or allogeneic stem cell transplantation for eligible patients.