Chronic Myelomonocytic Leukemia: Causes, Symptoms, and Treatment
Medically reviewed by Achuta Uppu, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats Chronic Myelomonocytic Leukemia?
A hematologist, a doctor who treats blood diseases, usually treats chronic myelomonocytic leukemia. An oncologist, a doctor who treats cancer, may also be involved. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What is chronic myelomonocytic leukemia?
Chronic myelomonocytic leukemia, or CMML, is a type of blood cancer. In CMML, the body tells too many blood stem cells to become two types of white blood cells called myelocytes and monocytes.
Some of these blood stem cells never become mature white blood cells. These immature cells are called blasts. Over time, the myelocytes, monocytes, and blasts crowd out the red blood cells and platelets in the bone marrow. Platelets are blood cells that help stop bleeding by forming clots. When this happens, infection or easy bleeding may occur.
Symptoms
Some people have symptoms that suggest they might have CMML. In other people with CMML, the first sign is an abnormal blood test result. Signs and symptoms can include:
- Fever for no known reason.
- Infection.
- Tiredness.
- Weight loss for no known reason.
- Easy bruising or bleeding.
- Pain or a feeling of fullness below the ribs.
These signs and symptoms may be caused by CMML or by other conditions.
Causes and who gets it
Risk factors for CMML include older age and being male. Being exposed to radiation, being exposed to certain substances at work or in the environment, and past treatment with certain anticancer drugs are also risk factors. Not every person with one or more of these risk factors will develop CMML.
How doctors diagnose it
If your doctor suspects CMML, they will do tests. They will test cells from your blood and most likely cells from your bone marrow too.
A complete blood count measures the levels of red blood cells, white blood cells, and platelets in your blood. People with CMML typically have high numbers of monocytes, a type of white blood cell. They also often have low numbers of other white blood cells, red blood cells, or blood platelets.
For a bone marrow aspiration and biopsy, samples of bone marrow are usually taken from the back of your hip bone.
Doctors also measure blasts in the bone marrow. For a diagnosis of CMML, there must be less than 20% blasts in the bone marrow. Chromosome testing can help doctors confirm that you have CMML and not a different type of leukemia.
Treatment
Treatment depends on a number of factors. These include your age and overall health, whether the CMML is causing symptoms, and how fast it seems to be progressing. They also include whether the CMML is in a higher or lower risk group.
For people who are not having symptoms, treatment might not be needed right away. Instead, doctors may just watch the CMML closely. Supportive care is used to treat all people with CMML, so they can live as well as possible. This care can include transfusions, blood cell growth factors, and antibiotics to treat infections.
If treatment is needed, chemotherapy is typically the first choice. It is done with either hydroxyurea or one of the hypomethylating agents, azacitidine or decitabine. A major benefit of azacitidine or decitabine is a reduced need for blood transfusions and an improved quality of life. Treatment may cause side effects, so ask your care team what to expect.
A stem cell transplant is a treatment to replace the blood-forming cells. In general, it is the only realistic way to try to cure CMML. It is often the treatment of choice for younger people with higher-risk CMML, if a matched stem cell donor is available. Other treatments aim to treat symptoms caused by the CMML and possibly slow its progression. Taking part in a clinical trial testing a newer treatment might be a good option for some people.
When to see a doctor
Check with your doctor if you have a fever for no known reason, an infection, tiredness, weight loss for no known reason, easy bruising or bleeding, or pain or a feeling of fullness below the ribs.
Call 911 or go to the emergency room if you have bleeding that will not stop, trouble breathing, or a sudden change in mental status, such as confusion.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. Either type of doctor can review your symptoms and order a complete blood count, a test that measures the levels of red blood cells, white blood cells, and platelets in your blood. Your doctor will test cells from your blood to see if you have CMML.
Common questions
Can chronic myelomonocytic leukemia be cured?
Possibly, but only with a stem cell transplant. In general, a stem cell transplant is the only realistic way to try to cure it. Other treatments aim to treat symptoms caused by the CMML and possibly slow its progression.
Does chronic myelomonocytic leukemia always need treatment right away?
No, not always. For people who are not having symptoms, treatment might not be needed right away. Instead, doctors may just watch the CMML closely.
Who is more likely to get chronic myelomonocytic leukemia?
Older people and men are more likely to get it. Having a risk factor does not mean you will get CMML.
Sources
- National Cancer Institute - Myelodysplastic/Myeloproliferative Neoplasms Treatment
- American Cancer Society - Tests for Chronic Myelomonocytic Leukemia
- American Cancer Society - General Approach to Treatment of CMML
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
