Certain rare blood cancers that appear when the body produces too many red blood cells, white blood cells, or platelets are called myeloproliferative neoplasms (MPNs), also known as myeloproliferative disorders. These blood cells are produced by a spongy tissue inside the bones called bone marrow. In people with MPNs, something affects the production of blood cells.
Mostly, these types of blood cancer develop slowly over time without causing any symptoms. In rare cases, these cancers can turn into more serious health conditions. MPNs cannot be cured, and doctors often recommend treatments to ease the symptoms, reduce the risk of serious complications, and improve your quality of life.
Types of Myeloproliferative Neoplasms
Generally, there are multiple types of MNPs. Check the most common of them below:
Polycythemia Vera
This form of MPNs is one of the most common types, and it causes the bone marrow to produce too many red blood cells. An excessive amount of these blood cells causes your blood to become thick, which affects blood flow through the bloodstream. Usually, people with polycythemia vera develop blood clots that significantly increase the risk for myocardial infarction (heart attack) and stroke. In rare cases, this type of MPN may progress to acute leukemia.
Myelofibrosis
This type of MPN is the most aggressive form, and it causes the bone marrow to make abnormal stem cells that become inflamed, which can lead to scar tissue. Over time, the bone marrow fills with scar tissue, which negatively affects red blood cell production (anemia). Typically, red blood cells carry oxygen to all tissues and organs in the body. In some cases, people with myelofibrosis also develop acute myeloid leukemia.
Essential Thrombocythemia
This form of myeloproliferative neoplasms occurs when the bone marrow produces too many platelets. In normal circumstances, when a blood vessel ruptures, platelets begin to produce blood clots that slow or stop bleeding. In people with essential thrombocythemia, the bone marrow continues to produce and release platelets when they are not needed, which often leads to blood clots that significantly increase the risk of a heart attack (also known as myocardial infarction) and a stroke. Most of the time, symptoms of essential thrombocythemia appear gradually over time.
Other Types of Myeloproliferative Neoplasms
These include:
- Chronic eosinophilic leukemia (CEL) – In this case, the bone marrow produces too many white blood cells (eosinophils). Rarely, people with CEL (also called hypereosinophilic syndrome) may also develop AML (acute myeloid leukemia).
- Chronic myelogenous leukemia (CML) – In such cases, the bone marrow produces too many granulocytes (a type of white blood cell), which negatively affects the bone marrow. Thus, it cannot produce enough of the other blood cells needed for your body.
- Chronic neutrophilic leukemia (CNL) – People with CNL often have an increased amount of neutrophils (another type of white blood cell) in the blood.
- Myeloproliferative neoplasm, unclassifiable (MPN-U) – This form of MPN does not fit in any other categories, and it causes the bone marrow to produce too many blood cells (including red blood cells, white blood cells, and platelets).
Symptoms
The symptoms usually appear gradually, and in the early stages of MPNs, people often do not have any symptoms. When the disorder progresses, you may experience symptoms of splenomegaly (enlarged spleen), including fullness, pressure, or discomfort below the ribs, among others. Furthermore, splenomegaly is one of the most common symptoms of most types of MPN. However, these disorders may also cause other symptoms, depending on the type a person develops. Check some examples below:
Chronic Eosinophilic Leukemia
One of the most common symptoms of this type of MPN is a skin rash, but it may also cause tiredness, fever, and other symptoms. They often appear in different parts of the body, depending on which part of the body is affected by increased levels of eosinophils.
Chronic Myelogenous Leukemia and Chronic Neutrophilic Leukemia
For example:
Essential Thrombocythemia
- Unusual bruising or bleeding from the mouth, gums, or nose
- Hematuria (blood in the urine)
- Bleeding from the intestines or stomach
- Bruising easily
Polycythemia Vera
- Vision changes (such as blurred or double vision)
- Extreme tiredness (fatigue)
- Headaches
- Dizziness
Primary Myelofibrosis
While most people with this type of condition experience anemia symptoms, including dyspnea, weakness, and fatigue, it may also cause other symptoms. Some of them are listed below:
- Fever
- Itching
- Pale skin
- Night sweats
- Abdominal fullness, especially after eating
- Unusual weight loss
- Bone pain
If any of the previous symptoms occur, immediately contact your healthcare provider. Otherwise, it may lead to unpleasant outcomes.
Causes and Risk Factors
Generally, all types of MPN are acquired genetic disorders, which means they cannot be inherited from the biological parents. They often occur when certain genes responsible for cell growth mutate or change, causing blood cell development to go wrong. According to some research, changes in the following genes usually cause MPNs. For example:
- Mutations associated with Janus kinases (JAK) – Usually, people who develop mutations (changes) associated with a protein known as Janus kinase 2 (JAK2) develop polycythemia vera, primary myelofibrosis, or essential thrombocythemia. Normally, these genes control the multiplication of cells.
- Mutations associated with the MPL or CALR genes – Those who develop primary myelofibrosis or essential thrombocythemia commonly have changes in these genes.
- Chromosome errors – In people with CML, there is a specific error that involves their chromosomes. Generally, a chromosome is a structure that contains genes. However, in people with CML, one chromosome swaps places with another chromosome, which forms a “Philadelphia chromosome”.
While experts have found these genetic mutations, they still do not understand what exactly causes them. Moreover, physicians have identified some factors that may increase your risk of developing MPNs. Check some examples below:
- Family history – Although MPNs are not inherited disorders, having a parent or sibling with these conditions significantly increases the risk of developing them.
- Sex – Usually, polycythemia vera mostly affects males, but essential thrombocythemia mostly occurs in females.
- Age – These health conditions can occur at any age, but most diagnosed cases are in people over 50 years old.
- Exposure to chemicals and toxins – Some studies have shown that people who are exposed to certain toxins (such as Benzene) are at increased risk for myeloproliferative neoplasms (including CML, primary myelofibrosis, and other types).
What Are The Possible Complications of Myeloproliferative Neoplasms?
People with MPNs may also experience some complications, especially if the condition is found in advanced stages or is left untreated. Check some of them below:
- Blood clots (thrombosis) – This is a dangerous complication that can cause DVT (deep vein thrombosis), pulmonary embolism, heart attack (myocardial infarction), and stroke.
- Excessive bleeding – It includes acquired bleeding disorders (such as von Willebrand syndrome).
- Microvascular problems – When a small blood vessel is blocked, it may lead to the following symptoms. Examples include headaches, a burning sensation in hands and feet, dizziness, and visual disturbances.
- Organ enlargement – The liver and spleen can become enlarged because they are trying to compensate for abnormal blood cell production. As a result, it may lead to abdominal pain, fullness, and portal hypertension (sometimes).
- Myelofibrosis (bone marrow scarring) – This is a serious complication that may cause severe anemia.
- Leukemic transformation – In some people, MPN may progress into a more aggressive disorder, such as AML (acute myeloid leukemia).
The previous list does not contain a full list of complications, but you can talk with your physician about preventive measures.
Diagnosis
Usually, it is challenging to diagnose MPNs. However, doctors will begin the diagnosis with a physical examination and questions about the symptoms and medical history. To confirm or exclude MPNs, physicians will perform the following tests and procedures. Examples include:
- CBC (complete blood count) – This is a type of blood test used to measure all blood cell levels.
- PBS (peripheral blood smear) – Commonly, doctors perform this test to identify abnormal cell shapes that often indicate an MPN.
- Bone marrow biopsy – During this procedure, doctors will take a small sample of bone marrow for testing. Thus, the pathologists will examine this sample under a microscope for differences between normal and abnormal cells.
- Genetic test – This test also involves a blood sample to check for abnormal genes that are often present in people with MPNs.
Treatment
While the only way to cure an MPN is allogeneic stem cell transplantation, it is not an option for everyone because some people may not be able to go through this strenuous process. In any case, physicians often prescribe treatments to ease the symptoms, prevent life-threatening complications, and improve your quality of life. For example:
- Chemotherapy – This cancer treatment involves strong medicines to destroy cancer cells throughout the body. In some cases, it can be prescribed along with radiation therapy to improve the effectiveness of the treatment.
- Radiation therapy – This is another cancer treatment that involves powerful energy beams to destroy the tumor. Usually, this energy comes from X-rays and protons, but it may also come from other sources.
- Targeted therapy – Physicians usually prescribe this cancer treatment when the previous options do not work. It also involves medicines, but they target a protein in the cancer cell, causing it to die.
- Immunotherapy – Most cancerous cells produce specific chemicals that help them hide from the immune system. This treatment helps boost the immune system to find and destroy cancer cells.
- Corticosteroids (to reduce inflammation)
- Anticoagulants (also known as blood thinners) – This group of medicines is primarily used to prevent or treat blood clots.
- Aspirin – Physicians recommend this medicine to reduce red blood cells, which helps prevent blood clots.
- Blood transfusion
Frequently Asked Questions
Are these diseases fatal?
While MPNs are not fatal disorders, they can cause life-threatening complications, including myocardial infarction and stroke.
How do MPNs affect my body?
These health conditions appear when the bone marrow begins to produce more of some blood cell than the body needs. That’s why MPNs can impact multiple parts of the body. For instance, a type of MPN significantly increases the risk of a heart attack and stroke because it causes the bone marrow to produce excessive red blood cells.
Can you live a normal life with MPN?
While the prognosis of this condition varies among people, if it is found in the early stages, people often have a near-normal life expectancy with treatment.
What is the life expectancy of someone with a myeloproliferative neoplasm?
Life expectancy depends on the specific type of MPN, the person’s age, overall health, and how well the condition responds to treatment. Many people with polycythemia vera and essential thrombocythemia live for decades with proper medical care and monitoring.
Are myeloproliferative neoplasms hereditary?
Most MPNs are not directly inherited from parents. However, having a close family member with an MPN may increase your risk of developing one. Researchers believe certain genetic and environmental factors contribute to the disease.
Can myeloproliferative neoplasms turn into leukemia?
Yes. In some cases, certain MPNs can progress to acute myeloid leukemia (AML), which is an aggressive form of blood cancer. The risk varies depending on the type of MPN and other individual factors.
How often should people with MPNs see their doctor?
Regular follow-up appointments are important to monitor blood counts, evaluate symptoms, and assess treatment effectiveness. The frequency of visits varies, but many patients require periodic blood tests and routine evaluations throughout their lives.
Can lifestyle changes help manage MPN symptoms?
While lifestyle changes cannot cure MPNs, maintaining a healthy diet, exercising regularly, staying hydrated, avoiding smoking, and following your treatment plan may help improve overall health and reduce the risk of complications such as blood clots.
Is pregnancy possible for women with myeloproliferative neoplasms?
Many women with MPNs can have successful pregnancies, but they are considered high-risk pregnancies and require close monitoring by healthcare providers. Certain medications may need to be adjusted before or during pregnancy to protect both the mother and baby.
When should I seek immediate medical attention if I have an MPN?
You should seek urgent medical care if you experience symptoms of serious complications, such as sudden chest pain, difficulty breathing, severe headache, weakness on one side of the body, vision loss, or unusual bleeding. These symptoms may indicate a blood clot, stroke, heart attack, or another medical emergency. Ask your healthcare provider if you have additional questions.
