Understanding Bone Marrow Aspiration & Biopsy

Blood disorders can sometimes prove to be fatal. Cancer or certain kind of infections can sometimes reach the bone marrow. Diagnostic tests like bone marrow aspiration or bone marrow biopsy can be useful in finding the reasons for such conditions.

It is important to understand the difference between bone marrow aspiration and bone marrow biopsy. In simple words, Bone marrow aspiration involves the removal of a small amount of bone marrow fluid and blood cells by passing a needle into a bone. These fluids and cells are further checked for particular kind of infection or any existing chromosomal problems. A bone marrow biopsy involves removal of a small amount of bone along with small amount of fluid and cells from inside the bone (bone marrow). The fluid is drawn first followed by a biopsy. It is useful for medical procedures like stem cell transplant or chromosomal analysis. For a stem cell transplant, this test is conducted at several places on the body (generally from the back of the pelvic bone) to remove enough bone marrow cells for the transplant to work.

Process

A bone marrow aspiration and biopsy can be done at your doctor’s clinic or a hospital. A hematologist, medical oncologist, internist, or pathologist, or a specially trained technologist usually conduct this test. A gown might be given to wear during the biopsy, as it may require removal of all or most of your clothes, depending on which part of the body the biopsy or aspiration is performed.

During the test

Before conducting the biopsy, a blood sample may be drawn from a vein in your arm. To prevent bleeding after biopsy, blood clotting medicines may be injected into a vein (IV) in your arm. However, bleeding is a rare thing to happen. A bone marrow biopsy is only taken from the pelvic bone.

Places where bone marrow fluid can be withdrawn:

Adults:

• From the back of the pelvic bone
• From the breastbone (sternum) – rarely done
• From the front of the pelvic bone – rarely done

Babies and young children

• From the front of the lower leg bone, just below the knee

A sedative is administered to help you relax. You will be made to lie either on your side or with your face down on your belly to conduct the biopsy. It is important to stay still and not move during the process.

• Firstly, the skin over the aspiration site is cleaned with a special solution and the area is numbed by applying a local anesthesia
• The aspiration needle is then put through the skin and into your bone, reaching the bone marrow
• Staying still while the sample is withdrawn is very important.
• A special tool is then used at the site that twists into the bone to remove some part of the bone. You might hear a crunching sound as the tool twists into your bone
• Post sample withdrawal, manual pressure is applied on the site to halt any excess bleeding
• The area is then covered with a bandage

How it feels

The process feels like a sharp sting and burns when the anesthesia numbs your skin at the biopsy site. You may find the procedure painful, but only for a few seconds. You may hear the crunching sound of your bone when the needle enters the bone. The site may feel stiff or sore for several days. You may also get a bruise on the biopsy site.

After the biopsy

You will be asked to stay in the lying position for 30 minutes to an hour post-biopsy to check the site for bleeding if any. The site may feel sore and application of ice packs to the site might prove helpful. Your doctor will also recommend some oral pain-killers if the pain is severe.

Results

Normal – The result is considered normal when the reports show a normal count of fats, iron, and connective tissue. This indicates the presence of normal numbers of both immature and mature bone marrow cells.
 Abnormal – Results can be abnormal if there is an abnormal count of fats, iron or connective tissue within the bone marrow. It can also be an indicator of the presence of some infection, abnormal-shaped cells can indicate the presence of cancer cells, like lymphoma, multiple myeloma, and more. In case scar tissue replaces the bone marrow then also such a situation can occur.
 
It is a complicated test and is not advised for patients who consume blood thinners. However, if you are facing recurrent bouts of infections within your body, then a sensitivity or a culture test of bone marrow can be used to provide accurate guidance in defining a treatment plan. If in case, you still have any confusions then it is best to discuss them with your doctor, before you finally opt to go for the examination procedure.