Multiple Endocrine Neoplasia Type 2 (MEN2)
People with multiple endocrine neoplasia type 2 (MEN2) have a higher risk of cancers of the endocrine system. Depending on the type of MEN2, they may also have a higher risk of other tumors and unique physical features.
- What is multiple endocrine neoplasia type 2 (MEN2)?
- What causes multiple endocrine neoplasia type 2 (MEN2)?
- Does multiple endocrine neoplasia type 2 (MEN2) increase a person’s cancer risk?
- What are the signs and symptoms of multiple endocrine neoplasia type 2 (MEN2)?
- How is multiple endocrine neoplasia type 2 (MEN2) diagnosed?
- How is multiple endocrine neoplasia type 2 managed and treated?
- Questions to ask your healthcare team
What is multiple endocrine neoplasia type 2 (MEN2)?
MEN2 is a hereditary condition that increases the risk of developing certain cancers and other conditions.
There are 2 main types of MEN2:
- MEN2A
- MEN2B
MEN2 is rare. It affects approximately 1 in 30,000 to 35,000 people. About 95% of people with MEN2 have MEN2A.
Both types cause tumors in certain glands of the endocrine system. Depending on the type, MEN2 can also affect other parts of the body.
The endocrine system includes glands and organs that make hormones. Hormones help control body functions like temperature, growth and development, and the levels of certain substances in the body, such as blood sugar and calcium.
The most common tumor in people with MEN2 is medullary thyroid cancer. Depending on the type of MEN2 a person has, they may also have a higher risk of:
- Pheochromocytomas, which are rare tumors in the adrenal glands (medulla)
- Hyperplasia of the parathyroid glands, which causes the glands to be larger than usual and produce too much parathyroid hormone
- Benign tumors of the nerves near the mouth, lips, tongue, and GI tract
What causes multiple endocrine neoplasia type 2 (MEN2)?
MEN2 is caused by certain gene changes (mutations) in the RET gene. MEN2 occurs when:
- A gene change is inherited from one parent, or
- A normal gene copy changes before a person is born, causing the gene change to be in cells throughout the body
The RET gene is a proto-oncogene. Normally, this gene helps certain cells grow and divide. When it's mutated, those cells can grow out of control. This can lead to cancer. Many different mutations can occur in the RET gene. Which mutation a person has affects which cancers, tumors, and other health conditions they're at risk for.
Does multiple endocrine neoplasia type 2 (MEN2) increase a person’s cancer risk?
Yes, MEN2 can increase the risk of certain types of cancer. Some of the MEN2-related tumors are not cancers, but some tumors are.
People with MEN2A can have a higher risk of:
- Medullary thyroid cancer
- Pheochromocytoma
- Parathyroid tumors (mostly benign)
People with MEN2B can have a higher risk of:
- Medullary thyroid cancer
- Pheochromocytoma
What are the signs and symptoms of multiple endocrine neoplasia type 2 (MEN2)?
The signs and symptoms of MEN2 depend on which type of MEN2 a person has and whether they have developed tumors related to the condition.
MEN2A signs and symptoms
Symptoms of MEN2A depend on which tumors develop. People with MEN2A may develop medullary thyroid carcinoma, a pheochromocytoma, and/or parathyroid gland hyperplasia. Each of these conditions can cause different symptoms.
Medullary thyroid carcinoma is a rare type of thyroid cancer. It can cause a lump in the neck that can be seen or felt. And it can cause neck pain. Other symptoms might include diarrhea and flushing.
Blood tests may also show levels of calcitonin that are higher than normal. This is a hormone made by the thyroid gland that helps lower calcium levels in the blood.
These are tumors of the adrenal gland, located above the kidneys. Some pheochromocytomas cause no symptoms. Others make high levels of hormones called catecholamines that cause symptoms such as:
- High blood pressure
- Fast or pounding heartbeat (palpitations)
- Sweating
- Changes in mood
Pheochromocytoma can cause high blood pressure that is difficult to control with medicine. When the blood pressure gets dangerously high, it can also cause trouble breathing, chest pain, headaches, or blurry vision.
Parathyroid gland hyperplasia is a condition where the glands grow larger than usual and make too much parathyroid hormone. This condition is called hyperparathyroidism.
When the parathyroid gland makes too much hormone, it raises calcium levels in the blood.
Symptoms of too much calcium in the blood might include increased thirst, needing to urinate more often, constipation, kidney stones, or low bone density.
In many cases, parathyroid hyperplasia causes no symptoms and is found only after blood work that is done for another reason finds high calcium levels.
Some families with MEN2A only have a higher risk of medullary thyroid cancer, with no increased risk of other MEN2A-related tumors. This form is called familial medullary thyroid cancer.
In less common cases, some people with MEN2A can also have Hirschsprung’s disease. This is a condition where the GI tract does not move stool properly. People with MEN2A might also have a skin condition called cutaneous lichen amyloidosis. This is an itchy, red-brown skin rash of the back, arms, or legs.
Whether you have these symptoms depends on what gene change caused MEN2A.
MEN2B signs and symptoms
Symptoms of MEN2B depend on which tumors develop. People with MEN2B may develop medullary thyroid carcinoma and/or a pheochromocytoma. MEN2B is more aggressive than MEN2A, and tumors are often diagnosed at younger ages.
Medullary thyroid carcinoma is a rare type of thyroid cancer. It can cause a lump in the neck that can be seen or felt. It can also cause neck pain. Other symptoms might include diarrhea and flushing.
Blood tests may also show levels of calcitonin that are higher than normal. This is a hormone made by the thyroid gland that helps lower calcium levels in the blood.
These are tumors of the adrenal gland, which are located above the kidneys. Some pheochromocytomas cause no symptoms. Others make high levels of hormones called catecholamines, which can cause:
- High blood pressure
- Fast or pounding heartbeat (palpitations)
- Sweating
- Changes in mood
Pheochromocytoma can cause high blood pressure that’s hard to control with medicine. When blood pressure gets dangerously high, it can also cause other symptoms like trouble breathing, chest pain, headaches, or blurry vision.
MEN2B can also cause small, benign (noncancerous) tumors of the nerves around the mouth, lips, and in the GI tract.
- Around the mouth, tumors may look like skin-colored bumps.
- In the GI tract, tumors may be seen on an imaging test, such as a colonoscopy. They can cause belly pain, bloating, or changes in bowel habits.
People with MEN2B may also have unique physical features. They may be very tall, have long arms and legs, have a curve of the back (scoliosis), and have very flexible or loose joints or skin.
How is multiple endocrine neoplasia type 2 (MEN2) diagnosed?
MEN2 is diagnosed based on a personal history of MEN2-related conditions combined with either genetic testing or a family history of close relatives with MEN2-related conditions.
Genetic testing might be recommended for:
- People diagnosed with medullary thyroid cancer or pheochromocytoma, especially if they are diagnosed at a young age, have a family member with one of these tumors, or have multiple tumors when diagnosed
- Close relatives of people with MEN2
- Parents of children with physical features of MEN2B
Having Hirschsprung’s disease or cutaneous lichen amyloidosis may also be a reason doctors recommend RET gene testing.
Genetic testing can be done on blood, saliva (spit), or a cheek (buccal) swab sample.
How is multiple endocrine neoplasia type 2 managed and treated?
MEN2 is managed with close follow-up and screening tests. Early screening tests may catch tumors before symptoms start, when treatment is more likely to be successful. There is no cure for MEN2.
If you are diagnosed with MEN2 before symptoms develop, doctors may recommend surgery to remove the thyroid gland (thyroidectomy) to prevent medullary thyroid cancer. Even after this is done, you have yearly screenings for other MEN2-related conditions.
Screening recommendations for people with MEN2
Regular screenings help manage your risk of MEN2-related conditions. Screening recommendations for medullary thyroid cancer, pheochromocytomas, and overactive parathyroid glands depend on:
- Which RET mutation you have, and
- How aggressive that mutation tends to be
- Yearly physical exam with blood pressure checks
- Surgery to remove the thyroid gland (thyroidectomy) before age 1
- Yearly tests for hormones (metanephrines and catecholamine metabolites) starting at age 11
- Yearly physical exam with blood pressure checks
- Yearly blood calcitonin levels and thyroid ultrasound starting at age 3
- Surgery to remove the thyroid gland (thyroidectomy) by age 5
- Yearly tests for hormones (metanephrines and catecholamine metabolites) and calcium levels starting at age 11
- Yearly physical exam with blood pressure checks
- Yearly blood calcitonin levels and thyroid ultrasound starting at age 5
- Surgery to remove the thyroid gland (thyroidectomy) in childhood or as a young adult depending on family preference and calcitonin levels
- Yearly tests for hormones (metanephrines and catecholamine metabolites) and calcium levels starting at age 16
Meeting with a genetic counselor may be helpful to understand your specific MEN2-related risk. For more information, see Understanding Genetic Testing for Cancer Risk.
Treatment of multiple endocrine neoplasia type 2 (MEN2)
There is no cure for MEN2. The way it is treated depends on the type of MEN2 you have, the age when you were diagnosed, and which tumors develop.
Before treating medullary thyroid cancer, your care team will check for an overactive parathyroid gland or pheochromocytoma. If you have a pheochromocytoma, it needs to be treated first. If it is untreated, it can make surgery more dangerous. If the parathyroid gland is overactive, that tissue may be removed during the surgery to remove the thyroid cancer.
Once these other conditions have been checked and treated, medullary thyroid cancer that has not spread is usually treated by removing the thyroid. Sometimes the nearby lymph nodes are also removed.
Radiation might be used if the cancer has spread or can’t be removed completely with surgery. If the cancer has spread to distant parts of the body or comes back after initial treatment, other medicines such as targeted therapy drugs may be tried.
After the thyroid gland is removed, you will need to take daily thyroid hormone replacement medicine.
For more information, see Treatment of Thyroid Cancer, by Type and Stage.
The main treatment is surgery to remove all or part of the adrenal gland, where the tumor is located. Before surgery, your care team will check whether the tumor is making hormones. If it is, they will give you medicines to block the effects of the hormones. This makes surgery safer.
If the tumor has spread, chemotherapy or targeted therapy might be used. If a tumor that has spread is causing symptoms, local treatments such as lasers or radiation might be considered.
If high parathyroid hormone levels are causing symptoms, treatment may include surgery to remove the parathyroid glands and sometimes nearby thymus tissue. If surgery is not an option, treatment can include medicines to lower calcium levels. If parathyroid tumors are not causing symptoms, no treatment may be needed.
Questions to ask your healthcare team
If you or a family member has MEN type 2, consider asking a member of your care team:
- What is my risk of developing cancer related to MEN type 2?
- Does my family history increase my risk of cancer? Should I get genetic testing?
- What cancer screening tests should I have? When?
- What signs or symptoms should I watch for?
- What can I do to lower my risk of cancer?
- Written by
- References
The American Cancer Society medical and editorial content team
Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as editors and translators with extensive experience in medical writing.
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Last Revised: August 20, 2026
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