It often takes a while to be diagnosed with an MPN, partly because there may be no symptoms in the early stages. In some cases, even if you did have symptoms, such as fatigue, these might have been mistaken for signs of other diseases.
Your doctor will need to carry out a number of tests before you are officially diagnosed with an MPN. More tests may be required to work out the type of MPN you have before it can be managed. This is to make sure that the management plan you’re given is the very best for you. You’ll also need to have regular blood tests to check on the progression of your condition.
1. A physical examination
Doctors begin by doing a physical examination, checking for symptoms such as an enlarged spleen which can occur in MPNs, and will also ask about your symptoms and your lifestyle.
2. Full blood count
Your doctor will take a sample of blood, to check for the number of red blood cells and platelets, and the number and type of white blood cells, as well as the amount of hemoglobin in red blood cells and the portion of the blood sample that is made up of red blood cells. This is known collectively as a full blood count or complete blood count (CBC).
3. Bone marrow aspiration and biopsy
This is done by inserting a hollow needle into the back of your hip bone (or, sometimes, the front of this bone or your breast bone) to remove a sample of marrow, the spongy material inside your bone. You may also have a bone marrow biopsy, which is performed in exactly the same way, but removes a small amount of bone, fluid and cells from inside the bone marrow.
The sample will be looked at in a lab. MPN bone marrow cells look different from normal cells, there may be too many or too few, and the bone marrow may have too much or too little iron. There might be signs of infection in the bone marrow, or it may have been replaced by fibrous or scar tissue.
Most people have had blood tests before, but the chances are a bone marrow test will be new to you. First, you’ll be given a local anesthetic to numb the area where the sample will be taken. Then the nurse will insert the hollow needle that will draw out the sample. You may hear a crunching sound when the needle goes into your bone, which can be a bit alarming, but is completely normal. You might also feel some pressure and perhaps pain. During an aspiration, you may notice a quick, shooting pain that goes down your leg as the sample is taken.
The procedure itself usually takes about 20 minutes. You might notice a bruise on the site and the area may feel stiff or sore for a few days.
4. Cytogenetic and molecular testing
The cells in your blood or bone marrow sample are examined under a microscope to look for the presence of the Philadelphia chromosome, a chromosomal abnormality which can lead to a diagnosis of chronic myeloid leukemia (CML) rather than ET, PV or MF. Other molecular tests will also look for the JAK2V617F (JAK2),CALR or calreticulin, and MPL mutations found in MPNs.
Any kind of medical test can make you feel anxious and with MPNs the process can be particularly stressful as you may end up having lots of tests before your doctor can give you a diagnosis. This can trigger anxiety, so here are some tips to help you manage: