A bone marrow biopsy removes a small amount of bone and a small amount of fluid and cells from inside the bone (bone marrow). A bone marrow aspiration removes only the marrow. They are often done to find the reason for many blood disorders and may be used to find out if cancer or infection has spread to the bone marrow.

• Bone marrow aspiration removes a small amount of bone marrow fluid and cells through a needle put into a bone. The bone marrow fluid and cells are checked for problems with any of the blood cells made in the bone marrow. Cells can be checked for chromosome problems. Cultures can also be done to look for infection.
• A bone marrow biopsy removes bone with the marrow inside to look at under a microscope. The biopsy of bone marrow is done first, and taking fluid (aspiration) is often done after the biopsy.

A bone marrow aspiration can also be done to collect bone marrow for medical procedures, such as stem cell transplantation or chromosomal analysis. For a stem cell transplant, bone marrow aspiration will be done 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.

Why It Is Done

A bone marrow aspiration, biopsy, or both are done to:

• Look for the cause of problems with red blood cells, white blood cells, or platelets in people who have conditions such as thrombocytopenia, anemia, or an abnormal white blood cell count.
• Find blood disorders, such as leukemia, certain anemias, or problems that affect the bone marrow, such as multiple myeloma or polycythemia vera.
• Check to see if a known cancer, such as Hodgkin's lymphoma or non-Hodgkin's lymphoma, has spread to the bone marrow. This is part of what is called staging. It is done to find out if the cancer has spread and how much it has spread. This helps plan cancer treatment. Staging can be done for other cancers, such as prostate, breast, or lung cancer that may have spread to the bone.
• Find infections or tumors that may start in or spread to the bone marrow. If you have an infection, a culture and sensitivity test of the bone marrow sample may be used to find out which antibiotics will work best to treat the infection.
• Find the best treatment for a bone marrow problem. Once treatment has been started, a bone marrow aspiration and biopsy may be done to see if the leukemia cells are gone, which means the treatment is working.
• Collect a sample of bone marrow for medical procedures, such as stem cell transplantation or chromosomal analysis.