Myelodysplastic Syndromes

This topic addresses Myelodysplastic Syndromes (MDS), a group of clonal stem cell disorders characterised by ineffective haematopoiesis, leading to peripheral blood cytopenias despite a hypercellular bone marrow. It is a complex but vital subject for Zambian tertiary students in haematology and pathology. The content explains the paradox of marrow failure coexisting with cellular hyperplasia and the tendency for progression to acute myeloid leukaemia (AML). Pathogenesis is linked to acquired genetic mutations affecting DNA methylation, chromatin modification, and RNA splicing. The topic details the FAB classification system, covering subtypes like Refractory Anaemia (RA), RA with Ringed Sideroblasts (RARS), and RA with Excess Blasts (RAEB). Key morphological features of dysplasia in different cell lineages (e.g., hypogranular neutrophils, pseudo-Pelger-Huët anomaly, ringed sideroblasts) are emphasised. Clinical presentation, often in older adults with symptoms of anaemia, infection, or bleeding, is discussed. For university and college learners, mastering MDS involves recognising the diagnostic hallmarks of dysplasia and cytopenias, understanding the risk of transformation, and differentiating it from other bone marrow failure states. This knowledge is crucial for accurate laboratory diagnosis, prognostic stratification, and exam success in advanced haematology modules.