Multiple Myeloma Diagnostic Test
Bone Marrow Biopsy
If multiple myeloma is suspected, several studies help confirm the diagnosis. They include a bone marrow aspiration and biopsy most commonly from the large bones of the pelvis. Cells obtained from the marrow are studied by a pathologist to determine if there is one (plasmacytoma) or more (multiple myeloma) abnormal types or numbers of cells. A sample of the bone marrow aspirate is also studied for more detailed characteristics such as the presence or absence of abnormal numbers or types of chromosomes (DNA) by what is called cytogenetic testing. Other molecular testing may be done on the marrow sample as well. The bone marrow biopsy can assess the concentrations of cells in the marrow and the presence of abnormal invasive growth of cellular elements.
What bone is used to sample the bone marrow?
The most frequent site for obtaining bone marrow is the pelvic bone, known as the ilium (posterior iliac crest). A portion of this bone is readily accessible in most people from the lower back and is usually marked by shallow dimples on either side of the spine. Other sites include the front of the pelvic bone near the groin and the sternum (breastbone) at the front of the chest. However, the sternum is sampled only for aspiration and done in individuals older than 12 years of age. This site is considered to be “a last resort” because the sternum is thin and there is risk of penetrating the underlying soft tissues. The tibia (shinbone) is sampled only in infants younger than 1 year of age; it is not sampled in adults because it may not yield a sufficient sample of bone marrow cells.
How do physicians perform a bone marrow aspiration and/or biopsy?
Typically, only a local anesthetic is required to numb the skin and tissue down to the surface of the bone although some patients may require a sedative. A physician makes a small cut (less than ¼ inch) in the skin and then uses a hollow needle, whose center is filled by a removable metal rod (called a trocar), to penetrate through the dense outer shell of bone. This needle (the most popular is termed the Jamshidi needle) can be used for both aspiration of marrow liquid or for a needle biopsy core of solid material. Once inside the bone, the trocar is removed and a syringe is attached to the now hollow tube of the bone marrow needle. The bone marrow is withdrawn as a thick liquid by pulling back on the plunger of the syringe and collecting the liquid. This sample is known as the marrow aspirate. This part of the procedure only lasts a few seconds but is usually the most painful due to the sudden sense of a negative pressure inside the bone.
A biopsy can also then be obtained in addition to the marrow aspirate or when an aspirate cannot be obtained. The same needle is used but without the center portion in place. As the needle is partially rotated into the bone, it cuts a core that is trapped inside the needle. Once the needle is removed, this core can be extracted from the needle barrel. This core can then be prepared with fixatives and stains for examination under a microscope.
Since the skin cut for both bone marrow procedures is usually very small, no stitches are generally necessary and only a bandage is applied. Recovery from the procedures is usually rapid (about one day, although some patients may feel tenderness at the site for about a week). Any post-procedure bleeding should be addressed by your physician. Those patients who require IV sedation will require someone to bring them home and should remain fairly sedentary for about 24 hours.
The cost of a bone marrow aspiration and/or biopsy varies greatly; it depends on the location (hospital or doctor’s office), insurance coverage, and the country. Consequently, the cost range is wide (from about several hundred dollars to several thousand dollars) and may or may not include additional testing of the sample.