Wednesday 3 February 2016

Bone marrow test

Bone marrow test

Nurse and patients talking about cancer    

This page tells you about bone marrow tests, what they are and what happens when you have one. You can find the following information
 

A quick guide to what’s on this page

Why you might have a bone marrow test

This test looks for cancer cells in your bone marrow. You may have it if you have alymphomaleukaemia or myeloma, or if your doctor wants to check if your cancer has spread to the bone marrow.

How you have the test

A doctor or specialist nurse removes a tiny sample of bone marrow cells to look at under a microscope. There are 2 types of bone marrow test.
Bone marrow aspiration – the doctor or nurse sucks out some bone marrow cells from your hip bone or breast bone (sternum) using a needle and syringe. A pathologistexamines the bone marrow cells in the laboratory.
Bone marrow trephine biopsy – the doctor or nurse removes a small core of bone marrow in one piece from the hip bone. This test shows the structure of the bone marrow inside the bone.
Each test only takes a few minutes and you can have them as an outpatient. First, your doctor gives you an injection of local anaesthetic into the skin over the area of the test. Then they put a needle with a syringe attached to it into the bone marrow. With an aspiration you may feel a pulling sensation as they draw the cells out. With a biopsy you may feel the needle turning. This can be painful but only for a short time. You may have a sedative to make you drowsy before the test.

After the test

The area may ache for a few days. Taking a mild painkiller such as paracetamol helps. It can take up to 2 weeks to get the full results of the bone marrow tests.

 

What a bone marrow test is for

This test is to see whether there are cancer cells in your bone marrow. For this test, a doctor or specialist nurse removes a tiny sample of bone marrow cells to look at under the microscope.

Types of cancer it is used for

Bone marrow tests are usually done for cancers that are most likely to affect the bone marrow, such as
But it can be done for any type of cancer if your doctor thinks your bone marrow could contain cancer cells, or needs to rule this out for any reason.
 

The types of biopsy

There are 2 main types of bone marrow test – a bone marrow aspiration and a bone marrow trephine biopsy. Aspiration means the doctor or nurse sucks some bone marrow cells up into a syringe. A bone marrow trephine means that they remove a 1 or 2cm core of bone marrow in one piece.
You usually have both of these tests done at the same time. They give some of the same information to the doctor, but there are differences. The bone marrow trephine biopsy shows the structure of the bone marrow inside the bone, whereas the aspiration takes just the bone marrow cells.
 

Having the test

Either test only takes a few minutes and you can have them done as an outpatient. The doctor or nurse usually takes the bone marrow sample from your hip bone. You can have a bone marrow aspiration from your breast bone (sternum) but not a bone marrow biopsy.
Below is an animation showing what to expect when you have a bone marrow test.

View a transcript of the video about bone marrow tests (opens in a new window).
You usually lie on your side with your knees tucked up into your chest. First the doctor or nurse cleans the area with some antiseptic fluid, which can feel cold. Then you have a local anaesthetic injection into the skin over the biopsy site to numb it. When this has worked, the doctor or nurse puts the needle in through the skin. It goes into the hip bone or sternum, and into the centre of the bone, where the marrow is. The needle is attached to a syringe. For a bone marrow aspiration, the needle is quite thin. For a bone marrow trephine, the needle is thicker.
If you are having a marrow aspiration, the doctor or nurse sucks a small amount of liquid bone marrow into the needle. You will feel a pulling sensation when they start drawing the bone marrow cells out. Some people have a sudden, sharp pain. If you are having a trephine biopsy as well, the doctor or nurse will take this needle out and put the second one in.
If you are having a trephine, the doctor or nurse will turn the needle back and forth while pushing it further into the marrow. The aim is to get a small amount of marrow out in one piece. Once it is in far enough, the doctor or nurse draws out the needle, containing its core of marrow. The needle going into the hip bone can be painful, but this only lasts a short time. The whole test takes 15 to 20 minutes.
Daigram showing a bone marrow test
Some people prefer to have some type of sedative before the test so that they are a bit drowsy. Sedation of some sort is certainly a good idea for children. If you have a sedative, you will need to stay at the hospital for a few hours until it has worn off. And you will need someone with you so that you don't have to go home on your own. Some hospitals may use gas and air (Entonox) to help relax you instead of sedation.
After the test, your hip may ache for a couple of days. You may need some mild painkillers such as paracetamol to take at home.
 

Possible risks from a bone marrow test

A bone marrow test is very safe and any risks are small.
Some people have a small amount of bleeding from the site where the needle went in. If you are on medication to thin your blood, such as warfarin, you may need to stop taking these before the test. Your doctor will advise you when and how long to stop taking them. You will have a dressing over the site which you should keep on for 24 hours. If you notice any bleeding apply pressure to the area. If it doesn't stop, contact the hospital.
There is a small risk of getting an infection in the wound. If you have a temperature or the area becomes red and sore let your doctor know.
During the procedure there is a very small risk of damage to nearby structures. The needles doctor use have a guard on them now which stops the needle going too deep so it is unlikely to be a problem.  
 

The results

It can take time for results to come through. Exactly how long may depend on why you are having the test. Generally, it can take a couple of days to get the results of the bone marrow aspirate, but the trephine result may take up to a couple of weeks.
The bone marrow sample is sent to the medical laboratory as soon as it has been removed. A pathologist examines it under a microscope. To do this, they may need to stain the cells so that the different types show up more clearly. The staining techniques can take a couple of days, depending on what needs to be done. The pathologist's report on the bone marrow sample will be typed up and sent to your specialist.
Understandably, waiting for results can make you very anxious. Try to remember to ask when you can expect the results when your specialist first suggests you have the test. If your doctor needs the test results urgently, they will have written that on the request form. If it isn't an emergency and you haven't heard after a couple of weeks, you can ring your doctor's secretary or specialist nurse to check if your results are back.

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