Bone Marrow Aspiration and Trephine Biopsy

Bone marrow is the soft part inside your bone which makes your blood cells. In a bone marrow biopsy, we take one or more samples including:
- Bone marrow aspirate - this is where we take a small sample of fluid from inside your hipbone (pelvis). These samples are then looked at under a microscope.
- Bone marrow trephine - this is where we take a small sample of your bone marrow using a hollow needle. It can then be looked at under a microscope.

You may need a bone marrow test because:

We have found a problem with your blood which needs to be investigated.
By looking closely at your bone marrow, we may be able to find out why there are changes in your blood.
This can help us to identify what is wrong and start you on the right treatment.
You are already receiving treatment for a blood disorder. The test lets us see how the treatment is working.

Bone marrow tests are low risk.
You may have some bleeding in the area where the needle is put in. This usually stops when pressure is put on the site, but you can be left with a small bruise.
You may develop an infection. This is rare and you can reduce the risk by keeping the area clean and dry after the test for 24 hours.

No. The only way to identify a problem in your blood is by looking at where it is made - in your bone marrow.

You can eat and drink normally before your appointment.
During the procedure you can have a friend, partner or family member present with you for support.
Please wear loose fitting clothing so we can do the test easily.
If you are taking warfarin, apixaban, edoxaban, rivaroxaban or any other medicines that thins your blood, such as heparin injections, follow the bridging plan (a temporary stopping of your blood thinning medication) given to you in clinic.
If you are taking aspirin or clopidogrel please follow the advice from your Nurse or Doctor.
Taking these medications is not harmful but it may take a little longer for bleeding to stop and there may be more bruising.
If you have any questions about your medications, you can:
Call: 07747 532 903 or 020 7288 5144
Email: adam.belton@nhs.net or whh-tr.haematologyteam@nhs.net

Injection image

The whole appointment will take an hour including our discussion beforehand.
You will need to lay on your side with your legs and knees tucked up into your chest. Please tell us if you find this difficult.
We will inject some local anaesthetic into the area above your buttock (bottom) to numb the area.
We then use one needle to take a small piece of bone marrow and a different needle to take some fluid from the hip. You may feel some pushing, pressure or a sharp sensation.
Please tell the doctor or nurse at any time if you feel very uncomfortable. We can provide more pain relief.

It is normal to have some bruising, pain and swelling.
If you have a high temperature or redness, bleeding, a lot of swelling or you feel generally unwell, please return to the Accident and Emergency Department at the hospital.

After the procedure

Stay on the ward for 10 to 20 minutes to make sure you feel well enough to go home.
You can take painkillers like paracetamol. You can use stronger painkillers if needed.
Keep the dressing on for 24 hours and keep it clean and dry, to reduce the chance of infection.
You can go home on your own (by bus, car, walking, etc)
Do not have a bath or shower for 24 hours.
Do not allow the dressing to get wet.
Do not take anti- inflammatory/NSAIDs such as ibuprofen or aspirin for pain as it can worsen bleeding and bruising.

We send the bone marrow sample to a laboratory to be looked at under a microscope.
Several tests are done. Your results can take up to four weeks to come back.
Your Doctor will discuss them with you at your next clinic appointment. A Doctor may contact you if it is urgent.
If you do not hear from us with your results after five weeks, call the department numbers below.

If you have any questions, please discuss them with your Doctor or Nurse during your appointment.
Before or after your test, you may contact us Monday to Friday 9am to 5pm:
Haematology Clinical Nurse Specialist: Adam Belton: Adam.belton@nhs.net or 07747 532 903.
Departmental admin staff: whh-tr.haematologyteam@nhs.net or 020 7288 5144.
For an urgent out of hours concern please call NHS 111 or go to the Accident and Emergency department.

Published:

26 Sep 2025

Review:

26 Sep 2027

Reference:

EIM/Haem/BMA&TB/01