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Myeloproliferative neoplasms are a group of rare disorders of the bone marrow that cause an increase in the number of blood cells.
You may also hear doctors call them MPN or myeloproliferative disorders (MPD).
Most people who develop myeloproliferative neoplasms are over 60.
The World Health Organisation (WHO) classes all myeloproliferative neoplasms as blood cancers. This is because the bone marrow is producing blood cells in an uncontrolled way. But many people with myeloproliferative neoplasms feel well and only need gentle treatment. The disorders often develop slowly and progress slowly. Or they can remain stable for a while.
Different myeloproliferative neoplasms affect different blood cells that form in the bone marrow. The bone marrow is the soft inner part of our bones that makes the blood cells.
All blood cells start from the same type of cell called a stem cell. The stem cell makes immature blood cells. These immature cells go through various stages of development before they become fully developed blood cells and are released into the blood as:
red blood cells to carry oxygen around the body
white blood cells to fight infection
platelets to help the blood clot
The diagram shows how the various different types of cells develop from a single blood stem cell.
Which type of myeloproliferative disorder you have relates to:
the type of blood cells affected
the number of blood cells in your bloodstream
your symptoms
There are a number of different types of myeloproliferative disorders. We have separate information on these types:
Chronic myeloid leukaemia (CML)
The following types are rarer:
chronic neutrophilic leukaemia (CNL) - a rare type of blood cancer affecting neutrophils, a type of white blood cell which helps us fight bacterial and viral infections
chronic eosinophilic leukaemia not otherwise specified (NOS) - this affects the eosinophils, a white blood cell which is involved in allergic reactions and used to fight parasites
There are also very rare myeloproliferative neoplasms that do not fall into any of the groups above. The World Health Organisation groups these together as 'MPN - not otherwise specified.
Many people with myeloproliferative neoplasms do not have any symptoms. You might be diagnosed after a routine blood test.
If you do have symptoms, they might include:
tiredness (fatigue)
bruising or unusual bleeding
getting more infections than usual
problems with your eyes - such as blurred vision
ringing in your ears
night sweats
itchy skin (pruritis)
weight loss
frequent headaches
If you do spot something unusual for you, tell your doctor. In most cases it won’t be cancer, but if it is, finding it early can make a difference.
Doctors use blood tests to diagnose myeloproliferative neoplasms. The blood tests show the number of blood cells and can look for genetic inside the blood cells.
You might also have some other tests. These might include:
a bone marrow test
an ultrasound of your tummy (abdomen)
chest x-ray
Other tests depend on your symptoms and your general health.
You can find out more about these tests on our tests and scans page.
The treatment you have depends on your type of myeloproliferative neoplasm.
The aim of treatment is usually to control symptoms rather than cure the condition. Treatments might include:
venesection - this is a simple procedure for people with a high red blood cell count. You will have around a pint of blood removed, which will reduce the number of red cells in your blood
drugs to control the blood count - these might include weak forms of chemotherapy or drugs that target the immune system
bone marrow or from a donor - this treatment aims to cure a myeloproliferative neoplasm. This treatment is not suitable for everyone. This is because it is an intensive treatment and it has many risks. Your doctor will tell you more about this if it is suitable for you.
We have more information on treatment for myelofibrosis, polycythaemia vera (PV) and essential thrombocythaemia (ET) on our other conditions main page.
Visit our main page for more information on these types
You can find out more about CML treatment in our CML treatment section.
Your specialist team will talk to you about your treatment options. They are there to answer any questions you might have.
There are some possible complications with MPNs. These depend on the type of MPN you have. Your doctor and specialist nurse will give you more information about these.
Complications might include:
blood clots (thrombosis)
bleeding
developing to acute myeloid leukaemia (AML)
scarring of the bone marrow
Your healthcare team might discuss ways to maintain a healthy lifestyle and help with stopping smoking if you need it.
We have information on healthy diet and lifestyle on our causes of cancer and reducing your risk pages.
Causes of cancer and reducing your risk
Coping with a rare condition can be difficult both practically and emotionally. Being well informed about your condition and possible treatments can make it easier to make decisions and cope with what happens.
It can also help to talk to people with the same thing. But it can be hard to find someone with a rare condition. You can look at Cancer Research UK’s discussion forum - Cancer Chat. It is a place to share experiences, stories and information with other people who know what you are going through.
MPN Voice is a UK organisation which offer information, support and advice about myeloproliferative neoplasms. They have leaflets and newsletters and also run regional forums where MPN patients can meet and hear about the latest MPN research.
Last reviewed: 07 Nov 2023
Next review due: 07 Nov 2026
CML starts in the white blood cells called granulocytes. It often develops slowly and treatment can keep it under control for many years. Find out more.
Polycythaemia vera (PV) is a rare blood cancer that affects the bone marrow.
Myelofibrosis is a rare blood cancer. It causes scarring of the bone marrow which can develop into acute leukaemia in some people.
Essential thrombocythaemia is a rare blood cancer that causes a high number of blood cells called platelets to form. These are blood cells involved in blood clotting.

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