Bone Marrow Aspiration

Bone marrow refers to the spongy tissue that is found inside the larger bones such as spine, breast bone, hips, ribs, legs and skull. Marrow has two parts – both solid and liquid. If the solid portion of the bone is sampled, it is called biopsy. Aspiration procedure is used to collect the liquid part of the marrow.

Both the procedures show whether the bone marrow is healthy and making normal amounts of blood cells. This procedure is normally used by doctors to diagnose and monitor blood and marrow diseases, including cancer. In bone marrow aspiration, the doctor uses a needle to draw a sample of the fluid portion. For a biopsy, a larger needle is used to take the sample of the solid part.

Most often bone marrow aspiration and bone biopsy is done at once. Together, they make the bone marrow examination. Although they are different procedures, they offer complementary information about bone marrow cells.

Why is it done?

Bone marrow aspiration and biopsy offer detailed information about the condition of the bone marrow and blood cells. In case the blood tests indicate that cell counts are abnormal, and information is not sufficient about a suspected problem, this is done. The doctor may perform bone marrow exam to diagnose a disease condition involving the bone marrow or blood cells:

• To determine a disease progression
  
• To check the iron levels and metabolism and
  
• To monitor treatment of a disease.

Pre bone marrow aspiration procedure

It is imperative to inform the doctor about any medications and supplements the patient is consuming. This can increase the risk of bleeding after a bone marrow aspiration. In case of anxiety or worry, better talk to the health care provider so that a sedative medication could be given before the aspiration in addition to a numbing agent through local anesthesia at the site where the needle is inserted.

Bone marrow aspiration is done in a hospital, a clinic or in a doctor's room. A specialist in blood disorders – a hematologist – or an oncologist, who is a specialist in cancer does the procedure with a nurse and a trained technologist. It usually takes about half an hour for the exam and if any intravenous sedation is given, extra time is taken for pre and post procedure care.

The patient's blood pressure and heart rate are checked. Some form of anesthesia is administered before the bone marrow aspiration as it can be painful. For many, local anesthesia is sufficient. You will be fully awake during the aspiration, but the site is numbed to reduce pain. If you are quite anxious, intravenous IV sedation is given before the marrow procedure.

Bone marrow aspiration procedure

The area for inserting the biopsy needle is marked and cleaned. The bone marrow fluid (aspirate) is usually collected from the top ridge of the back of the hipbone, and if it is done from the breast bone or the front of the hip near the groin. In young children and kids, the sample is taken from the lower leg bone, just below the knee. The patient will be made to lie down on the abdomen or side.

The bone marrow aspiration is usually done before the biopsy. A small incision is made to insert the needle easier. A hollow needle is inserted through the bone and into the bone marrow. Several samples are taken and aspiration takes only a few minutes. While the health care team ensures that sufficient quantity of sample is drawn, sometimes a 'dry tap' may occur, that is fluid cannot be withdrawn. The needle is moved for another attempt.

Post aspiration procedure

After the bone marrow exam, pressure is applied to the where the needle was inserted to stop the bleeding. A smaller bandage is placed on the site. If local anesthesia had been administered the patient is asked to lie back for 10-15 minutes and apply pressure on the biopsy site. In case, IV sedation had been given, you are taken into a recovery area as sedatives may cause impaired judgment, memory lapses or slowed response.

Tenderness may be felt for a week or more after the bone marrow exam, and the doctor administers pain reliever. You need to keep the bandage dry for 24 hours and not shower or bathe, or swim or use the hot tub. It is okay to get the aspiration site wet after 24 hours. In case bleeding soaks through the bandage, or does not stop even with direct pressure, consult the doctor. The doctor also needs to be contacted if there is persistent fever, worsening pain, swelling at the procedure site and increasing redness or drainage at the procedure site. Also it is advised to avoid rigorous activity for a couple of days to minimize bleeding and discomfort.

Results from bone marrow aspiration

The sample is sent to a laboratory for analysis. The results are available in a few days. The pathologist or hematologist evaluates the samples to check the health of the marrow and if it has enough healthy blood cells and also for abnormal cells. The doctor confirms or rules out a diagnosis and how advanced the disease is or if the treatment is working. Sometimes, follow-up tests are done.

Risks of bone marrow examination

This is a safe procedure and complications are rare. But some complications include:

Excessive bleeding which can happen in people with low platelet count.
Infection in those with weakened immune systems.
Discomfort that could be long lasting in the biopsy site.
Heart and lung problems can be caused due to penetration of the breastbone.
Sedation can cause allergic reaction, nausea and irregular heartbeats in some.

Uses of bone marrow exams

These are used for many conditions including:

• Anemia
  
• Bone marrow disorders which include myelodysplastic syndrome and myelofibrosis.
  
• Blood cell conditions such as Leukopenia, leukocytosis, thrombocytopenia, thrombocytosis, pancytopenia and polycythemia – which produce too few or too many of certain types of blood.
  
• Cancers of the bone marrow or of blood including leukemia, lymphomas and multiple myeloma.
  
• Cancers that have spread to other areas including breast.
  
• Hemochromatosis and
  
• Infections.

While problems with bone marrow can create lasting and serious health problems, bone marrow exams, such as aspiration and biopsy are important to help determine the status and extent of problems in the cells to evaluate and determine further treatment and management.

Bone marrow biopsy

Bone marrow biopsy is a technique to remove a small section of the tissue from the body to study it under the microscope for any further analysis and tests. This test is recommended by doctors if they see an abnormal result in the complete blood count of a person or for examining any other regular disease that might be present in the bone marrow. Bone marrow biopsies are used to check for blood disorders like leukemia, certain types of anemia or problems affecting the bone marrow such as multiple myeloma or polycythemia vera. Besides they can throw light on any infections or cancers that are originating in the bone marrow. A bone marrow biopsy aids in studying abnormal appearance and numbers of red blood cells, white blood cells or platelets in conditions such as thrombocytopenia. It is essential to keep the health care provider of any medications that are taken. A local anesthetic is usually given to numb the skin. A sedative may be prescribed to calm the patient throughout the bone marrow biopsy procedure.

• Samples are usually taken from the hip bone after cleaning the area.
  
• A biopsy needle is inserted into the bone.
  
• Core of the needle is removed and the needle is turned in both the directions thus forcing a small sample of the bone marrow into the needle.
  
• The needle is removed from the site and pressure is applied on that area to restrict bleeding and the area is bandaged.
  
• There might some discomfort after the biopsy needle is removed as the anesthesia effect cannot reach the bone interiors.
  
• Bone marrow biopsy will take about 20 minutes and after the biopsy you may be asked to lie down for another 60 minutes to check for bleeding from the site.

Results of bone marrow biopsies are available after 1 to 3 days. Normal results are indicated by normal numbers of mature and growing bone marrow cells. Abnormal results of a bone marrow biopsy are indicated by abnormal appearance of normal numbers of mature and growing bone marrow cells and presence of fibrous tissue in the bone marrow. There may be special stains that confirm infection in the bone marrow.

Reticulocyte Count Test

Blood is a precious fluid. Plasma, white blood corpuscles and red blood corpuscles are the three kinds of cells in the blood. The blood cells are normally made in the bone marrow. To know the level of red blood cells in the blood, reticulocyte count test is done.

Reticulocyte Count Test

Reticulocyte are immature red blood cells made by the bone marrow. Reticulocytes are in the blood for two days before developing into mature cells. Reticulocyte count test is done to determine if red blood cells are being made in the bone marrow at an appropriate rate. The count indicates how quickly reticulocytes are being produced and released by the bone marrow.

Need for Reticulocyte count test

Paleness, tiredness, weakness, shortness of breath, and/or blood in the stool are symptoms when doctors recommend Reticulocyte count test to:

• Assess the functioning of bone marrow i.e. if enough red blood cells are made by the bone marrow.
  
• Diagnose and distinguish the different kinds of anemia and the reasons for anemia, if it is due to fewer red bloods or due to great loss of red blood cells.
  
• Evaluate reasons for chronic bleeding and or/blood in the stool.
  
• Monitor progress after chemotherapy, bone marrow transplant, treatment for iron deficiency etc.
  
• Determine the degree and rate of increased number of RBCs and elevated hemoglobin (rare occurrence) and hematocrit.

Reticulocyte count test - Preparation

There isn't any specific preparation required before Reticulocyte count test. However, it is recommended to check with health care provider if any specific pre test preparation is needed. Those who have had a recent blood transfusion should inform the doctor. This can affect test results. Important information to be shared with the doctor is about medicines being taken. Women who are pregnant and mothers who are breastfeeding infants should talk to doctor before opting for the test.

Reticulocyte count test Method

The test result is available few hours after collecting blood or the next day. An elastic band is wrapped around the upper arm to stop the flow of blood. Sample of blood from the vein of the arm is taken. A drop of blood is placed on a slide, smeared, stained and is examined under a microscope. This is the manual method. Automated methods that allow for greater number of cells to be counted are most likely to replace the manual method.

Reticulocyte count test result Interpretation

The number of reticulocytes is compared to the total number of red blood corpuscles (RBC) and is reported as a percentage of reticulocytes.

Reticulocyte (%) = [Number of Reticulocytes / Number of total Red Blood Cells] X 100

In a healthy adult person, the normal range is 0.5% to 1.5%. In kids, the normal range is 3% to 6%. This is a stable percentage. The normal range may slightly vary.

High reticulocyte count suggests more red blood cells are being made by the bone marrow. This could be due to acute bleeding, chronic blood loss, hemolytic anemia, kidney disease and potentially a fatal blood disorder in the fetus or new born - erythroblastosis fetalis (Erythroblastosis Fetalis refers to a serious blood disorder in infants - Rh incompatibility disease and ABO incompatibility disease) or hemolytic disease. Also, the count increases post treatment for certain anemia like iron deficiency anemia, pernicious anemia, or folic acid deficiency anemia.

Erythroblastosis Fetalis refers to a serious blood disorder in infants - Rh incompatibility disease and ABO incompatibility disease. Low reticulocyte count suggests fewer red blood cells are being made by the bone marrow. This can be due to aplastic anemia or iron deficiency anemia. Other instances such as exposure to radiation, a chronic infection or due to intake of certain medicines (drug toxicity) can lead to low count.

The reticulocyte count increases temporarily during pregnancy. The count is high in newborns but within few weeks the count drops to adult levels. In case the result is abnormal more tests may be administered for further analysis.