Myelodysplastic syndrome


Myelodysplastic syndrome is a group of disorders when the blood cells produced in the bone marrow do not mature into healthy cells. This leaves you with fewer healthy blood cells in your body. The blood cells that have matured may not function properly.

Myelodysplastic syndrome (MDS) is a form of cancer. In about a third of people, MDS may develop into acute myeloid leukemia.

Alternative Names

Myeloid malignancy; Myelodysplastic syndrome; MDS; Preleukemia; Smoldering leukemia; Refractory anemia; Refractory cytopenia


Stem cells in bone marrow form different types of blood cells. With MDS, the DNA in stem cells becomes damaged. Because the DNA is damaged, the stem cells can’t produce healthy blood cells.

The exact cause of MDS is not known. For most cases, there is no known cause.

Risk factors for MDS include:

Prior cancer treatment increases the risk for MDS. This is called secondary or treatment-related MDS.

MDS usually occurs in adults age of 60 years and older. It is more common in men.


Early stage MDS often has no symptoms. MDS is often discovered during other blood tests.

People with very low blood counts often experience symptoms. Symptoms depend on the type of blood cell affected, and they include:

Exams and Tests

People with MDS have a shortage of blood cells. MDS may reduce the number of one or more of these:

The shapes of these cells may also be changed. Your health care provider will perform a complete blood count and blood smear to find which type of blood cells have been affected.

Other tests that may be performed are:

Some of these tests will help your provider determine what type of MDS you have. This will help your provider plan your treatment.

Your provider may define your MDS as high-risk, intermediate-risk, or low-risk on the basis of:

Since there is a risk of MDS developing into AML, regular follow-up with your provider may be required.


Your treatment will depend on several factors:

The goal of MDS treatment is to prevent problems due to a shortage of blood cells, infections and bleeding. It may consist of:

Your provider may try one or more treatments to see what your MDS responds to.

Outlook (Prognosis)

The outlook will depend on your type of MDS and severity of symptoms. Your overall health also may affect your chances of recovery. Many people have stable MDS that does not progress into cancer for years, if ever.

Some people with MDS may develop acute myeloid leukemia (AML).

Possible Complications

MDS complications include:

When to Contact a Medical Professional

Contact your provider if you:


National Cancer Institute website. Myelodysplastic/myeloproliferative neoplasms treatment (PDQ) - health professional version. Updated January 26, 2022. Accessed May 9, 2022.

Nguyen PL, Hasserjian RP. Myelodysplastic syndromes. In: Hsi ED, ed. Hematopathology. 3rd ed. Philadelphia PA: Elsevier; 2018:chap 18.

Steensma DP, Stone RM. Myelodysplastic syndromes. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 172.

Review Date: 10/28/2021
Reviewed By: Todd Gersten, MD, Hematology/Oncology, Florida Cancer Specialists & Research Institute, Wellington, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. Editorial update 05/09/2022.
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