MDS is an updated term for what was previously known as pre-leukemia. It refers to a group of blood disorders that occur when specific types of blood cells become dysfunctional.

Myelodysplastic syndrome (MDS) used to be referred to as “pre-leukemia,” or sometimes “smoldering leukemia.” MDS is a group of conditions that occur when blood-forming cells found in bone marrow become abnormal. It can cause you to have low levels of:

  • red blood cells
  • white blood cells
  • platelets

Several different types of MDS exist. They’re primarily based on what the cells look like when viewed under a microscope. Though other factors, such as how many types of blood cells are affected, also play a role.

Symptoms of MDS can vary depending on which type (or types) of blood cells are affected. Many people with MDS have no symptoms, and their diagnosis is made with incidental findings on blood work.

If they do occur, possible MDS symptoms include:

1. Fatigue

MDS can cause low levels of red blood cells, a condition known as anemia. Red blood cells are important because they carry oxygen and nutrients throughout your body. This can result in fatigue, a well-known symptom of anemia.

Other symptoms of anemia include:

  • shortness of breath
  • lightheadedness, dizziness
  • pale skin
  • cold hands and feet
  • general weakness
  • irregular heart rate
  • headache
  • chest pain

Symptoms of anemia tend to get worse over time.

2. Unexplained bruising or pinpoint spots on the skin

You may experience some skin symptoms if MDS causes thrombocytopenia, or low levels of platelets.

Platelets are an important component of your blood that enable it to clot. Problems with blood clotting, such as a lack of sufficient blood clotting when needed, can cause bleeding into your skin, leading to unexplained red, brown, or purple bruises, known as purpura, or red or purple pinpoint spots, known as petechiae.

These pinpoint spots may be raised or flat on the skin. They usually aren’t itchy or painful, but they stay red even if you press on them.

3. Bleeding easily

Low platelet levels can cause you to bleed easily, even after just a minor bump or scrape. You may also experience spontaneous nosebleeds or bleeding gums, especially after dental work.

4. Frequent infections

Frequent infections may be caused by low levels of white blood cells, also known as neutropenia. A low white blood cell count is known as leukopenia. White blood cells are an important part of your immune system, helping your body fight off infection.

Low levels of white blood cells can make you more susceptible to infections that affect your:

  • lungs
  • throat
  • sinuses
  • skin
  • mouth
  • ear
  • gums

5. Bone pain

If MDS becomes severe, it can cause bone pain.

MDS is caused by defective bone marrow stem cells. Bone marrow is the material found inside your bones. It’s where your blood cells are made. Stem cells are a type of cell found in your bone marrow that are responsible for producing your blood cells.

In MDS, these bone marrow stem cells start producing abnormal blood cells that aren’t properly formed and die too quickly or are destroyed by your body. This leaves your body with too few functioning blood cells to carry oxygen, stop bleeding, and fight infections.

It’s not always known what causes the defective stem cells, although scientists think that genetic mutations may be the cause. There are two classifications of MDS. Most people have primary MDS, or de novo MDS. In primary MDS, the defective bone marrow stem cells have no known cause.

Secondary MDS is treatment related. It usually occurs in people who have been treated for cancer. This is because chemotherapy and radiation therapy can damage the stem cells in your bone marrow.

Several factors can increase your risk of developing MDS:

  • previous treatment with chemotherapy
  • previous radiation therapy or other long-term exposure to radiation
  • long-term exposure to high levels of benzene or toluene

The vast majority of people diagnosed with MDS are in their 70s. It’s uncommon to develop the condition before age 50. Men are more likely than women to develop MDS.

If you are at higher risk of developing MDS and have some of the symptoms, make an appointment to see your doctor.

Since many people with MDS have no symptoms, or only minor symptoms, a routine blood test is often your doctor’s first clue that something is wrong. In MDS, blood counts are usually low. But in some cases, the white blood count level or platelet counts are higher than normal.

Your doctor will have you take two other tests to check for MDS: a bone marrow aspiration and a bone marrow biopsy. During these procedures, a thin, hollow needle is inserted into a hip bone to remove a sample of marrow, blood, and bone.

A microscopic analysis of the chromosomes, known as a cytogenetic study, will reveal the presence of any abnormal bone marrow cells.

An allogeneic blood and marrow transplantation (BMT), also known as a bone marrow transplant or stem cell transplant, is the only potential cure for MDS.

BMT involves using high dose chemotherapy drugs followed by infusion of donor blood and bone marrow. It can be a dangerous procedure, especially for older adults. It isn’t appropriate for everyone.

When BMT isn’t an option, other treatments can reduce symptoms and delay development of acute myeloid leukemia (AML). Some of these are:

  • transfusion therapy to increase the number of red blood cells and platelets
  • antibiotics to prevent infection
  • chelation therapy to remove excess iron from the blood
  • growth factor therapy to increase the number of red blood cells
  • chemotherapy to kill or stop the growth of fast-growing cells
  • epigenetic therapy to stimulate tumor-suppression genes
  • biologic therapy to improve red blood cell production in people missing the long arm of chromosome 5, otherwise known as 5q minus syndrome

Symptoms of MDS and early AML are similar. About one-third of people with MDS eventually develop AML, but early treatment for MDS can help delay onset of AML. Cancer is easier to treat in the earliest stages, so it’s best to get a diagnosis as quickly as possible.

Q: Is myelodysplastic syndrome considered a cancer?


A: Myelodysplastic syndrome (MDS) is considered a cancer.

It’s a set of conditions that occur when cells in the bone marrow that produce new blood cells are damaged. When these damaged blood cells form new blood cells, they develop defects and either die earlier than normal cells or the body destroys the abnormal cells, leaving the patient with low blood counts.

In about one-third of patients diagnosed with MDS, acute myeloid leukemia develops due to progression of rapidly growing cancer of the bone marrow. Because this condition does not occur in most MDS patients, the terms “pre-leukemia” and “smoldering leukemia” are no longer used.

Christina Chun, MPHAnswers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.
Was this helpful?