How are the Myelodysplastic Syndromes diagnosed?
Full blood count
Low blood counts are picked up by a simple test called a full blood count (FBC). The FBC test provides a number of results that provide information about red and white blood cells and platelets.
Many different conditions can result in increases or decreases in the cell populations. Normal FBC values for children are different from adults. The laboratory will supply the reference ranges for various age groups, and a healthcare professional will take these into consideration when interpreting data.
It is important to rule out other causes of a low blood count so the doctor will ask general health questions and give you a physical examination.
The laboratory performing the test will then examine the blood cells on a slide (called a blood film) under the microscope. If you are found to have changes on the blood film that suggest MDS, you will usually be referred to a blood specialist (haematologist).
Bone marrow test
As MDS is a disease of the bone marrow, a bone marrow test is usually needed to diagnose the condition.
A small amount of bone and bone marrow are taken, generally from the pelvis (hip bone). The doctor will numb the area with local anaesthetic and a needle is inserted into the bone marrow cavity. A small liquid sample is taken followed by a biopsy. Preparing the sample and analysing all the results can take two to three weeks. The bone marrow sample is processed in the laboratory and examined by a doctor under a microscope to look for changes seen in MDS.
Bone Marrow Test
Additional tests are often requested on the bone marrow sample, which may help to make the diagnosis and provide information about how the disease will behave (prognosis). These include cytogenetics (sometimes called a ‘karyotype’), which is the study of the changes in the structure of the chromosomes in the affected cells.
In most cases of MDS, the typical features are present in the bone marrow and the diagnosis is straightforward. However, unlike most other diseases, there is currently no specific diagnostic test for MDS and so reaching a diagnosis can sometimes be challenging and take a little longer than expected.
Understanding MDS and genetic mutations
People on our helpline often ask for a simple explanation of MDS and genetic mutations. The animation below, from the MDS Foundation, simplifies this complex topic and provides clear explanations for discussing with your consultants and nurses.