The peripheral blood smear usually demonstrates low cell counts (ie, anemia, thrombocytopenia, leukocytopenia) and dysplastic features in RBCs (basophilic stippling, megaloblastic changes, etc) and/or WBCs (hyposegmented or hypersegmented granulocytes, hypogranularity, etc).
The bone marrow aspirate and biopsy will usually show hypercellularity, as well as single- or multi-lineage dysplasia. Maturing RBCs may show nuclear budding, irregularity, or bridging. Ring sideroblasts may be seen. Megakaryocytes may show hypolobulation of the nucleus. Myeloblasts may be present; however, they must comprise less than 20% of cells. Certain cytogenetic abnormalities may also be present that can determine the subtype of MDS.
Depending on MDS subtype, patients may be at higher risk of developing acute myeloid leukemia (AML).
D46.9 – Myelodysplastic syndrome, unspecified
109995007 – Myelodysplastic syndrome
Differential Diagnosis & Pitfalls
- Poor nutritional status can lead to dysplastic features of blood cells. Causes include copper deficiency, zinc excess, vitamin B12 deficiency, folate deficiency, and alcohol use disorder.
- Certain medications can mimic MDS findings.
- Inherited disorders such as sideroblastic anemia may present with similar abnormalities.
- HIV infection
- Aplastic anemia
- Chronic myelogenous leukemia (CML)
- VEXAS syndrome
Drug Reaction Data