Bone Marrow Biopsy
What Is A Bone Marrow Biopsy?
A bone marrow biopsy is the removal of soft tissue, called marrow, from inside bone. Bone marrow is found in the hollow part of most bones. It helps form blood cells.
Why Do I Need A Bone Marrow Biopsy?
A Bone Marrow Biopsy is recommended when the baseline blood tryptase levels are greater than 20ng/ml in adults or there are other reasons for suspecting systemic mastocytosis.
Once consent is obtained from the patient, the procedure is usually carried out as a day case under a local anaesthetic.
The bone marrow histology can give us important information:
- Firstly, it can confirm the diagnosis of systemic mastocytosis when abnormal numbers or types of mast cells are seen within the bone marrow.
- Secondly, as bone marrows from many patients are analysed, the collected data over the years has allowed to differentiate between characteristics of the less aggressive (indolent or benign) mast cells from the more aggressive type of mast cells.
Bone marrow findings cannot be interpreted on their own to classify the type of systemic mastocytosis. The blood count, serum tryptase levels and the presence of any organ damage should be taken into account before making a final diagnostic.
Occasionally, when the bone marrow has been infiltrated by mast cells, it is because there is another underlying blood disorder which itself increases mast cell production as part of a process different from systemic mastocytosis.
How The Test is Performed
A bone marrow biopsy may be done in the health care provider's office or in a hospital. The sample may be taken from the pelvic or breast bone. Sometimes, other areas are used.
The health care provider will clean the skin and inject a numbing medicine into the area. Rarely, you may be given medicine to help you relax.
The doctor inserts the biopsy needle into the bone. The center of the needle is removed and the hollowed needle is moved deeper into the bone. This captures a tiny sample, or core, of bone marrow within the needle. The sample and needle are removed. Pressure and a bandage are applied to the biopsy site.
A bone marrow aspirate may also be performed, usually before the biopsy is taken. After the skin is numbed, the needle is inserted into the bone, and a syringe is used to withdraw the liquid bone marrow. If this is done, the needle will be removed and either repositioned, or another needle may be used for the biopsy.
How to Prepare for the Test
Tell the health care provider:
- If you are allergic to any medications
- What medications you are taking
- If you have bleeding problems
- If you are pregnant
You must sign a consent form.
How The Test Will Feel
You will feel a sharp sting when the numbing medicine is injected. You may feel a brief, sharp pain when the liquid (aspirate) is removed.
The biopsy needle may also cause a brief, usually more dull, pain. Since the inside of the bone cannot be numbed, this test may cause some discomfort. However, not all patients have such pain.
Here's a short video of a biopsy. Viewer discretion advised.