Myeloproliferative neoplasms (myeloproliferative disorders) are rare blood cancers that occur when your body makes too many red blood cells, white blood cells or platelets. Your healthcare provider can work with you to relieve symptoms, slow disease progression and prevent complications.
Myeloproliferative neoplasms (MPNs) are rare, potentially life-threatening blood cancers that happen when your bone marrow makes too many blood cells. Blood cells include red blood cells, white blood cells and platelets. They’re made in the spongy tissue inside of your bones. With a myeloproliferative neoplasm, something goes wrong in the blood cell production process.
Myeloproliferative (pronounced “MY-eh-loh-proh-LIH-feh-ruh-tiv) neoplasms develop very slowly, so people may have them for years before noticing symptoms. Myeloproliferative neoplasms are also called chronic myeloproliferative neoplasms or myeloproliferative disorders. Chronic means that a condition is long-term. Rarely, a myeloproliferative neoplasm may turn into a more serious disease.
There are treatments that ease symptoms and reduce the risk of a myeloproliferative neoplasm developing into a more serious disease.
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Depending on the type of myeloproliferative neoplasm, your bone marrow may make too many red blood cells, white blood cells, platelets or a combination of cell types. The cells often behave differently from healthy blood cells.
Your age and sex are the most significant predictors of how likely you are to have a myeloproliferative neoplasm.
These blood diseases happen when your bone marrow makes more of a certain blood cell type than your body can use. The impact on your body varies based on the blood cell type affected. For example, one type of myeloproliferative neoplasm increases your risk of heart attack or stroke. Another type may cause anemia.
To understand these rare diseases, it may help to have some information about your bone marrow and blood cell production. All blood cells start as stem cells in your bone marrow. Your bone marrow is soft, sponge-like tissue in the center of your bones. It makes cells that may become myeloid stem cells or lymphoid stem cells.
Lymphoid stem cells become white blood cells that help fight infection. Myeloid stem cells can become red blood cells that carry oxygen throughout your body, white blood cells or platelets, which prevent excessive bleeding.
Like all cells, stem cells take instruction from genes that help dictate cells’ form and function. Normally, your bone marrow makes stem cells that divide and multiply as needed. These stem cells follow directions from genes that help regulate cell development.
When these genes mutate, they send new instructions to certain stem cells, telling the cells to keep on dividing and multiplying. Eventually, these stem cells become mature blood cells that pile up in your bone marrow or bloodstream, affecting blood flow. Blocked blood flow can cause serious medical conditions.
The three most common types are polycythemia vera, essential thrombocythemia and primary myelofibrosis.
This is the most common myeloproliferative neoplasm. It makes your bone marrow produce too many red blood cells. The excess red blood cells make your blood thick, so blood moves more slowly through your bloodstream. People with polycythemia vera are likely to develop blood clots that may cause heart attack and stroke. Very rarely, polycythemia vera may progress or become serious blood diseases, including acute leukemia.
This is the most aggressive myeloproliferative neoplasm. In myelofibrosis, your bone marrow produces abnormal stem cells that become inflamed and make scar tissue. Over time, your bone marrow fills up with scar tissue. The scar tissue keeps your bone marrow from making enough red blood cells to carry oxygen throughout your body, and you may develop anemia. Your bone marrow also falls behind on platelet production. Platelets help to slow and stop excessive bleeding. Some people with myelofibrosis will develop acute myeloid leukemia.
Essential thrombocythemia happens when your bone marrow makes too many platelets. If a blood vessel ruptures, platelets make blood clots that slow or stop bleeding. In essential thrombocythemia, your bone marrow makes platelets even when there’s no need for them. These excess platelets become blood clots that increase your risk of having a heart attack or a stroke. Like other myeloproliferative neoplasms, essential thrombocythemia symptoms develop very slowly. Most people learn they have this disease when routine blood tests show high platelet levels. Some people with essential thrombocythemia may develop leukemia.
Other MPN types include:
You likely won’t notice symptoms in the early stages. As your condition progresses, you may notice signs of an enlarged spleen (splenomegaly). Splenomegaly feels like fullness, pressure or discomfort below your ribs on your left side, where your spleen is located. While splenomegaly is a common symptom of most myeloproliferative neoplasms, it’s a less common symptom of essential thrombocytopenia.
Other symptoms depend on the specific myeloproliferative neoplasm.
The most common symptom is a rash. You may also feel tired and feverish. Other symptoms depend on what body parts are affected by your high eosinophil levels.
Symptoms may include:
Symptoms may include:
Symptoms may include:
You may experience symptoms of anemia (fatigue, weakness, shortness of breath). Other signs and symptoms may include:
All myeloproliferative neoplasms are acquired genetic disorders. This means you can’t inherit these diseases from your biological parents. These diseases happen when genes that regulate cell growth mutate or change and your blood cell development goes wrong.
Medical researchers have made the following discoveries about the genetic mutations that cause myeloproliferative neoplasms:
These discoveries don’t clarify what causes genetic changes to take place. Still, they help healthcare providers make a diagnosis and develop treatments targeting genetic mutations.
Family history, age and sex may increase the risk of developing MPN.
Researchers have also found links between myeloproliferative neoplasms and certain toxins and radiation exposure. Some studies show people exposed to high levels of radiation and certain toxins like benzene have an increased risk of developing myeloproliferative neoplasms, like polycythemia vera, primary myelofibrosis and chronic myelogenous leukemia.
A healthcare provider will collect a detailed medical history and perform a physical exam to check for signs and symptoms of a myeloproliferative neoplasm. They’ll run tests on your blood and bone marrow to make a diagnosis.
Allogeneic stem cell transplantation is the only known cure for these diseases. Unfortunately, many people can’t have stem cell transplantations because they may not be able to go through the strenuous stem cell transplant process.
Your healthcare provider will provide treatments that manage your condition by reducing the number of blood cells, providing symptom relief and preventing complications. There are some treatments that can lead to remissions. MPN treatments vary by type:
Experiences vary based on many factors, including the type of myeloproliferative neoplasm, how early your condition was diagnosed and how you respond to treatment. With careful monitoring and treatment, many people live for several years. There’s no single prognosis or expected outcome for these conditions. In general, people diagnosed with MPN are alive five years later. Survival rates for specific MPNs are:
If you have this condition, ask your healthcare provider to explain your prognosis. They know all the factors that affect prognosis. Just as important, they know you, including risk factors like your age and overall health that affect your prognosis.
On their own, these aren’t fatal diseases, but some may cause life-threatening conditions such as heart attack or stroke.
Myeloproliferative neoplasms are a complex group of diseases with multiple treatment options that sometimes cause side effects. Similarly, various complications can arise depending on your condition. It’s important to know what signs or symptoms you should be aware of. Talk to your provider so you understand your diagnosis and can make care decisions.
Questions may include:
It can be confusing living with a myeloproliferative neoplasm. You may feel fine and wonder if there’s anything you can do to prevent symptoms. If you’re receiving treatment, you may need help managing treatment side effects and symptoms. Either way, you’ll likely be living with your disease for years to come. Here are some suggestions that may help:
If you have a myeloproliferative neoplasm but don’t have symptoms, contact your healthcare provider if you notice changes in your body that may indicate you’re developing symptoms.
A note from Cleveland Clinic
Myeloproliferative neoplasms (MPNs) are rare, potentially life-threatening blood cancers that happen when your bone marrow makes too many blood cells. In some ways, myeloproliferative neoplasms are mysterious diseases. Researchers know myeloproliferative neoplasms involve abnormal blood cell growth. They know these are genetic disorders, but they don’t know what triggers the genetic mutations that cause MPNs. They’re rare diseases so many people don’t know what it’s like to live with a myeloproliferative neoplasm. But healthcare providers and researchers are learning more about myeloproliferative neoplasms, particularly more effective ways to manage symptoms and reduce the risk of serious medical complications.
Last reviewed by a Cleveland Clinic medical professional on 09/01/2022.
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