29th May 2023

Investigations

• Bloods – rule out other causes for cytopenias. Anaemia can be normocytic or macrocytic.
  • Blood film shows dysplastic features in at least one lineage (see image below of a dysplastic neutrophil)
• Bone marrow – usually hypercellular with evidence of dysplasia. Blasts may be present (<20%)
• Cytogenetic analysis is important for risk stratification.

Blood film showing a dysplastic neutrophil – the cytoplasm is hypogranular and there is a pseudo-Pelger-Huet nucleus. The accompanying red cell changes in this case are actually a result of splenectomy.
Image Source: Wikimedia Commons (2021). Myelodysplasia, Licensed under a creative commons licence. Available for free at: https://commons.wikimedia.org/wiki/File:Myelodysplasia.jpg (Accessed on: 10 January 2023).

Subtypes of MDS:

1. MDS with single lineage dysplasia
2. MDS with multi lineage dysplasia
3. MDS with ring sideroblasts
4. MDS with excess blasts 5-9%
5. MDS with excess blasts 10-19%
6. MDS with isolated del 5q

Some variants of MDS overlap with proliferative phenotypes (MDS/MPN overlap). They show features of both dysplasia and proliferation. Chronic myelomonocytic leukaemia (CMML) is an example.