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.
In the past, Chronic myelomonocytic leukaemia (CMML) was considered a type of MDS. In CMML, one specific type of white cell is raised in the blood. Bloodwise provides a CMML Factsheet. Other booklets from Bloodwise with loads of useful information are available on their download page: Patient information booklets.
This presentation is very scientific, but stresses the importance of knowing your exact gene mutations.
Treatments such as Azacitidine are mentioned to be of benefit, but clearly much more needs to be done for patients with this specific type of MDS/MPN overlap disease.
This is also the reason why it is crucial to be seen at a specialist center for MDS if you have been diagnosed with CMML
Learn more about Myelodysplastic Syndromes (MDS) and use this information to discuss with your consultants and nurses.
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