To help investigate or diagnose a disease or condition affecting the bone marrow or blood cell production; sometimes for staging of a lymphoma or solid tumor; to measure response to treatment for a previously diagnosed condition like leukemia
Bone Marrow Aspiration and Biopsy
When you are anemic without an obvious cause; when you have or are suspected of having a blood-related disorder or cancer that may be affecting blood cell production; sometimes when a healthcare practitioner is investigating a fever of unknown origin, especially when you have a weakened immune system (immunocompromised)
A bone marrow sample collected primarily from the hip bone (pelvis)
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How is it used?
Bone marrow aspiration and biopsy are procedures used to evaluate the blood cells within the bone marrow, as well as its structure. They are performed in conjunction with a complete blood count (CBC) and blood smear and sometimes additional testing on the bone marrow to provide information about the health of the bone marrow and its capability for blood cell production, including red blood cells (RBCs), white blood cells (WBCs), and platelets.
Using the information from the examination, a bone marrow aspiration and/or biopsy may be used to help:
- Determine the cause of unexplained low or high blood cell counts, including too few or too many white blood cells (leukopenia or leukocytosis), too few or too many red blood cells (anemia or polycythemia), or too few or too many platelets (thrombocytopenia or thrombocythemia)
- Identify the cause of abnormal or immature blood cells present in the blood, as detected by a CBC or a blood smear
- Diagnose and subclassify cancer originating in the bone marrow (e.g., leukemia, multiple myeloma)
- Diagnose other bone marrow disorders, such as myelodysplastic syndrome (MDS)
- Diagnose and stage a variety of other types of cancers, such as lymphoma or solid tumors, that may involve or have spread to the bone marrow
- Diagnose conditions that affect the marrow and its fibrous structure, such as myelofibrosis
- Evaluate for a bone marrow infection if a person has a fever without an apparent cause (fever of unknown origin)
- Diagnose a disorder associated with iron storage that may cause stored iron to diminish
If a person is being treated for a cancer, a bone marrow aspiration and/or biopsy may be ordered to evaluate the response to treatment to determine whether suppressed marrow function is beginning to return to normal.
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When is it ordered?
Bone marrow examination is not routinely ordered. However, it may be ordered when results of other tests, such as a CBC and/or blood smear, are abnormal and a bone marrow examination is warranted.
Bone marrow examination may be ordered when an individual's medical history, physical examination, and signs and symptoms suggest the presence of a disease affecting the bone marrow.
The tests may be ordered when staging certain cancers or when it is suspected that other cancers have spread to the bone marrow.
A bone marrow biopsy and aspiration may also be ordered at intervals when a person is being treated for a cancer to evaluate response of the cancer cells to treatment, whether marrow function is being suppressed by therapy, and, if it is, when its function begins to recover.
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What does the test result mean?
The laboratory report for these tests may include a description of the cells seen and the appearance of the bone marrow environment. Results from a complete blood count (CBC) and blood smear are usually included. Typically, the specialist provides an interpretation of the findings and any other details that might be important in the diagnosis, staging, or treatment of the disease.
In many cases, this information can confirm or rule out a diagnosis and whether the bone marrow is affected by disease, but it can also point out the need for further investigation. For example, a patient with decreased red blood cells (RBCs) and no increase in reticulocytes may have aplastic anemia with suppressed RBC production in the marrow. An evaluation of the bone marrow may confirm this condition, but it does not necessarily tell the healthcare practitioner the specific cause.
The healthcare practitioner uses the information from the marrow evaluation and combines it with information from a clinical examination, medical history, blood tests, and a variety of other tests, such as imaging scans and X-rays, to reach a final diagnosis. It can be a straightforward process or it can be a complex diagnostic puzzle. Patients should stay involved in this process by talking to their health care provider before and after a bone marrow biopsy and/or aspiration, asking what the suspicions are, what kind of information is expected from the evaluation, and what follow-up tests might be indicated.
A variety of disorders and conditions may be identified, monitored, and/or staged with this process. A few examples include:
- Leukemia — cancer of the blood cells
- Anemia — low number of red blood cells and low hemoglobin
- Diseases such as aplastic anemia that can affect the marrow's ability to produce an adequate number of each of the different blood cell types and release them into circulation.
- Myelodysplastic syndrome — a group of disorders associated with dysfunctional and ineffective bone marrow that leads to decreased production of one or more types of blood cells
- Myeloproliferative neoplasms — a group of diseases characterized by the production of too many of one or more types of blood cells in the bone marrow. (e.g., chronic myeloid leukemia, polycythemia vera, essential thrombocythemia)
- Myelofibrosis — disorder characterized by the overgrowth of the fibrous network found in the marrow, compressing cells and leading to changes in red blood cell shape and changes in the cell counts
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Is there anything else I should know?
Complications from the bone marrow aspiration and/or biopsy procedure are extremely rare, but they can include excessive bleeding at the collection site or an infection. Individuals should tell their healthcare provider about any allergies they have and about any medications or supplements they are taking prior to the procedure and should contact their healthcare provider promptly if they experience persistent or spreading redness or bleeding at the site, a fever, or increasing pain.
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Will I be given general anesthesia for a bone marrow aspiration and/or biopsy?
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My report includes an M/E ratio. What is it?
M/E ratio is short for myeloid to erythroid ratio. This is the number of myeloid cells compared to the number of erythroid cells within the bone marrow. Myeloid cells are those that mature into granulocytes (neutrophils, eosinophils, basophils), and erythroid precursor cells mature into red blood cells. This result is not diagnostic of any condition but is an additional piece of information that the health practitioner may use to help determine the health of the bone marrow. For example, in the case of bacterial infection, the M/E ratio will increase due to an elevated number of granulocytic cells, whereas in case of hemolytic anemia, the M/E ratio will decrease due to an increase in erythroid cells.
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How does a bone marrow aspiration and/or biopsy compare with a bone marrow collection for donation?
Nowadays, instead of a bone marrow collection for donation, donors of hematopoietic stem cells are usually given a medication that stimulates their bone marrow to release immature cells into the blood, and those cells are collected in a process very similar to a normal blood donation. After processing, the stem cells in the donor sample are infused into the recipient and travel through the bloodstream to the recipient's marrow spaces and, if all goes right, begin to produce red blood cells, white blood cells, and platelets.




Smear prepared from bone marrow aspiration sample showing the variety of cells normally present, including cells of different lineages at different maturation stages. The large megakaryocyte (platelet precursor) is prominent (arrow). The marrow cells are surrounded by fat cells (empty spaces). Image credit: Chuanyi Mark Lu MD, PhD


Section of bone marrow core biopsies showing the marrow structure and various components of the marrow. In the normal bone marrow (left), the trabecular bone (thick arrow) and the fat cells (thin arrows) through which the hematopoietic cells percolate can be seen. In the biopsy from a patient with leukemia (right), the fat cells and the normal marrow cells have been replaced by the leukemic cells, which appear darker because of their large nuclei. Courtesy: Chuanyi Mark Lu MD, PhD and Karen Chisholm MD