Bone Marrow Exam for CML
- A biopsy is a medical procedure that involves taking a small sample of body tissue so it can be examined under a microscope.
- A bone marrow biopsy is considered the gold standard as part of the diagnostic workup for CML.
- The procedure is generally recommended to ensure a patient is in the chronic phase (vs. blast phase) and to ensure that there have not been additional chromosome changes outside of the traditional Philadelphia chromosome.
- Despite being an important exam, it’s not for everyone.
CML, is a form of blood cancer that develops in the soft, spongy center of long bones: the bone marrow. It affects a subtype of white blood cell (the cells that fight infections), called a “myeloblast.” Normal myoblasts grow, divide and mature into white blood cells. In patients with CML, the bone marrow makes abnormal myeloblasts that don’t mature properly. That results in a huge amount of abnormal white blood cells in the body. These abnormal cells do not fight infections, and instead spill into the blood in large numbers, causing a variety of serious problems.
What is a biopsy?Read More
The procedure is often performed on an outpatient basis and done by a doctor who specializes in blood disorders (hematologist) or cancer (oncologist). But it may also be performed by nurses with special training.
At that time, you may have a twinge of pain, but it is usually manageable due to the anesthetic lidocaine given before the procedure starts. The skin is then bandaged and you may shower, but should not bathe or swim for 48 hours.
Once performing the biopsy, a pathologist will look at the cells in the bone marrow in order to conclude whether they are abnormal or the number of cells are low or high.
“They look at the bone marrow in several different ways. They look at what’s called the morphology or the actual shape of the cells. And that is what tells them if the cell is truly a blast (the most primitive form a leukemia cell), and they quantify those blast cells,” Dr. Tanaka told SurvivorNet. According to the percentage of blasts, the medical team can determine on which CML phase the patient is.
Phases of Chronic Myeloid Leukemia
Most patients (about 90%) are diagnosed with chronic myeloid leukemia at the chronic phase (when there are no significantly noticeable symptoms) through routine checkups and abnormal blood work.
– Chronic phase: less than 5% of immature leukemic blast cells (the abnormal white blood cells) are found in the bone marrow. This phase can be well controlled with oral medications in nearly all cases. Left untreated, patients will eventually progress to the accelerated or blast phase. However, this can take years to happen.
– Accelerated phase: symptoms like night sweats, fatigue, weight loss, and frequent infections start to manifest more clearly as the number of blast cells starts to increase. During this phase, the white blood cells become increasingly unable to mature normally, and there are between 10% – 20% leukemic blast cells in the blood or bone marrow. Accelerated phase CML is more difficult to control with medications, probably because of new mutations that develop in the CML cells. This stage can take from three to nine months. Similarly, if left untreated patients will progress to the blast phase.
– Blast phase: this is the most aggressive form of CML, with noticeable symptoms. If there are more than 20% blast cells in the blood or bone marrow, this means that the patient is in the blast phase, also called “blast crisis. SurvivotNet has put together some information on this topic to help you or a loved one should a diagnosis arise: What are the Treatment Options for Advanced — or “Blast” Phase — Chronic Myeloid Leukemia?
Bone marrow biopsies are generally safe procedures. But like any invasive procedures, complications can occur. The main risk of this procedure is hemorrhage, or excessive bleeding, particularly in people with low numbers of a certain type of blood cell (platelets). Aspirin or other pain medicines may raise your risk of bleeding. Be sure to take only medicines your healthcare provider has approved.
Other reported complications include:
- Infection, generally of the skin at the site of the exam, especially in people with weakened immune systems.
- Bruising at the biopsy site.
- Long-lasting discomfort at the bone marrow exam site.
- Allergic reaction to anesthesia.
Questions to Ask Your Doctor
- Is there a need for a bone marrow biopsy?
- How long will the procedure last?
- Will it hurt and can I do anything to help that pain?
- What are the main risks and complications?
- Are there any alternative tests or procedures?
- When and how will I get the results?