Definition and Overview
A bone marrow biopsy is one of the two procedures performed in a bone marrow examination, the other one being the bone marrow aspiration. The procedure, which involves removing a tiny sample of the marrow for further examination, is typically ordered by an oncologist, a haematologist, or a pathologist if the initial blood test reveals abnormal results or does not provide enough information to make a diagnosis.
Found in the interior of the bones, the bone marrow is the spongy tissue that contains immature cells, called stem cells. Examining the biochemical and cellular components of the bone marrow is useful in determining the presence of a wide variety of medical conditions.
A healthy bone marrow produces normal amount of blood cells. Abnormalities or irregularities in the amount of blood cells produced by these tissues typically lead to the development of medical conditions such as cancer as well as diseases that affect the marrows and the blood. These conditions are diagnosed through bone marrow biopsy. Some doctors also use this procedure to determine the cause of inexplicable fevers or to observe the current condition of the patient's blood cells, as well as to monitor the progress of treatment of an existing medical condition.
The group of tissues that make up the bone marrow has two different textures—a more fluid, almost liquid part, and a comparatively more solid portion. Both of these tissue portions are required for a bone marrow examination; the more solid part is drawn using a needle in a biopsy, while the more fluid part is drawn in a bone marrow aspiration. These two procedures are often performed at the same time, offering the physician two different yet complementary sets of information.
Who should undergo and expected results
Bone marrow examinations are prescribed for patients who:
- Have blood test results that show irregularities or abnormalities
- Are suspected of having medical conditions that involve the bone marrows and the blood cells they produce
- Are suffering from specific medical conditions (bone marrow biopsy can determine the current stage or progression of certain diseases)
- Have a medical condition that requires the monitoring of their metabolism and iron levels
- Were diagnosed with bone marrow or blood diseases (the purpose of the biopsy in this case is to determine if the treatment plan is working)
- Suffer from inexplicable fever
- Are suspected of having blood diseases, such as anaemia, leukocytosis, leukopenia, pancytopenia, thrombocytopenia, polycythaemia, and thrombocytosis as well as leukaemia, multiple myeloma, lymphoma, and other blood or bone marrow cancers.
- Are suspected to be suffering from cancers that have metastasized to the bone marrow
- Are suspected of having hemochromatosis, a condition that is characterized by the overproduction of iron in the blood
Healthy individuals typically have normal levels of red and white blood cells in their bone marrow, as well as a normal amount of platelets. With enough blood cells in the body, the individual can easily fight off infection and diseases, keep the organs in great working condition, and allow the blood to clot properly.
However, if prior blood tests show low amounts of blood cells and platelets, the doctor can order a bone marrow biopsy and use the information gathered to determine the root cause of these abnormal results.
How the procedure works
Bone marrow biopsy is performed under anaesthesia or mild sedation to free the patient from pain or discomfort once the needle is inserted into the skin and then through the bone. When performed together with a bone marrow aspiration, the procedure takes about 30 minutes to complete. The patient will have to lie on his or her belly during the procedure.
Most doctors take bone marrow samples from the top ridge of the hipbone while some prefer to take samples from the chest bone. A small incision is made in the target area, where a hollow needle is inserted. This needle will penetrate the bone, and will collect a cylindrical sample, known as the core sample.
After the sample is collected and properly inserted into corresponding containers, the doctor will bandage the incision. The patient will be allowed to rest before he or she can go home. It is best for the patient to arrange for a ride home.
Possible risks and complications
Bone marrow biopsies are generally safe, but there are some rare instances that entail some complications and risks, because the procedure is performed under anaesthesia, the patient may have an allergic or adverse reaction to the drug used. In patients with very low platelet counts, the insertion of the needle to draw the tissues can cause excessive bleeding.
Very rarely, a patient can suffer from an infection, or discomfort where the needle is inserted long after the procedure. Again, these complications are quite rare and have only been observed in patients who have existing conditions that make their immune systems weak. Some conditions also lower the patient's platelet counts, which can lead to serious complications.
Choby B. Bone marrow aspiration and biopsy. In: Pfenninger JL, Fowler GC, eds. Pfenninger & Fowler's Procedures for Primary Care. 3rd ed. Philadelphia, PA: Elsevier Mosby; 2010:chap 205.
Hutchison RE, McPherson RA, Schexneider KI. Basic examination of blood and bone marrow. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 22nd ed. Philadelphia, Pa: Elsevier Saunders; 2011:chap 30.