Bone Marrow Examination (this include a procedures known as bone marrow aspirate and trephine biopsy)
Either test only takes a few minutes and you can have them done as an outpatient. The doctor takes the bone marrow sample from your hip bone.
The procedure is carried out with the patient lying on one side.
First you will have the area of skin cleaned. You will then have a local anaesthetic injection into the skin over the biopsy site – your hip bone – to numb it. When this has worked, the doctor puts the needle in through the skin, into the hip bone, and into the centre of the bone, where the marrow is. For a bone marrow aspiration, the needle is quite thin. For a bone marrow trephine, the needle is thicker. The needle is attached to a syringe.
If you are having a marrow aspiration, the doctor then sucks a cubic millilitre of bone marrow cells into the needle. You may feel a pulling sensation when the doctor starts drawing the bone marrow cells out. Some people have a sudden, sharp pain. If you are having a trephine biopsy as well, the doctor will take this needle out and put the second one in. Sometimes if the needle has touched a nerve you may feel a pain shooting down the leg on the side the marrow was taken.
If you are having a trephine, the doctor will turn the needle back and forth while pushing it further into the marrow. The aim is to get a 1 or 2 centimetre core of marrow out in one piece. Once it is in far enough, the doctor will draw out the needle, containing its core of marrow. The needle going into the hip bone will be painful, but it doesn’t last for too long.
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 until it has worn off. And you will need someone with you so that you don’t have to go home on your own.
After the test, your hip may ache for a couple of days. You may need some mild painkillers to take home or your doctor may suggest you take some paracetamol. We also suggest that you lie on your back for at least 15 minutes after the marrow has been taken and that you leave the dressing on for at least 24 hours.
The results
The bone marrow may be sent for the following tests:
- Morphology
- Histology
- Immunophenotyping
- Cytogenetics
The first 3 results will generally be back in 7-10days. Cytogenetic results can take 2-4 weeks to come back.