Different Types of MDS

What are the Different Types of Myelodysplastic Syndromes?

There are many types of MDS and this can be difficult to understand. Spend time talking to your doctor or nurse about this. It’s important that you know and understand your exact diagnosis.

There is a generally accepted classification system for separating the different types of Myelodysplastic Syndromes. The World Health Organization (WHO) regularly updates this classification.

The current classification (2016) is based on the blood results, the appearance of the bone marrow, the number of abnormal immature cells and any chromosome changes found. The immature cells are called blasts, which may be increased in some of the types of MDS.

There are six broad types of MDS included in the current 2016 classification. These are:

  • MDS with single lineage dysplasia (MDS-SLD)
  • MDS with multilineage dysplasia (MDS-MLD)
  • MDS with ring sideroblasts (MDS-RS)
  • MDS with excess blasts (MDS-EB); MDS-EB-1 and MDS-EB-2
  • MDS, unclassifiable (MDS-U)
  • MDS with isolated del(5q) or with 1 additional abnormality

'Dysplasia' means that the bone marrow cells look abnormal.

In MDS with multilineage dysplasia, dysplasia is seen in cells of 2 or 3 cell types, i.e. red blood cells, white blood cells, and/or megakaryocytes - the cells that make platelets; in single lineage dysplasia dysplasia is seen in only 1 cell type.

Sideroblasts are young red blood cells that have a very distinctive ring of iron granules seen under the microscope.

Del(5q) is a specific type of MDS where chromosome tests show part of the chromosome five is missing.

New Edition! Understanding Myelodysplastic Syndromes

This booklet has been written to help you understand more about MDS. Learn more about the different types of MDS in Chapter 5.

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Chronic Myelomonocytic Leukaemia

CMML is a form of leukaemia characterised by high numbers of white blood cells, called ‘monocytes’, in the blood and bone marrow. In the past, it was considered a type of MDS.

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Learn more about Myelodysplastic Syndromes (MDS) and use this information to discuss with your consultants and nurses.

Evidence tells that being actively involved in your own treatment can improve your outcomes and experience of the disease.

All the articles on our website have been properly vetted by MDS experts for scientific accuracy.

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