Multiple endocrine neoplasia (MEN) is a group of rare genetic conditions that increase the risk of certain tumors in your glands. Parathyroid, thyroid, adrenal glands, and digestive tract tumors are most common.
MEN1 and MEN2 are the two main categories of MEN. MEN4 is much rarer. There is no MEN3, but MEN2 can be subdivided into several types.
The type of tumors that develop in people with MEN depends on the subtype. Almost everybody with MEN1 develops parathyroid tumors while almost everybody with MEN2 develops a type of thyroid tumor called medullary thyroid cancer (MTC).
Here, we examine MEN in more detail, including types, symptoms, and treatment options.
MEN1 and MEN2 are the two main categories of MEN. Less is known about MEN4 since fewer than 100 cases have been reported.
MEN type 1
MEN1 occurs in about
Other commonly associated tumors include:
MEN type 2
MEN2 occurs in about
MEN2 can be further broken down into three
| Subtype | Medullary thyroid carcinoma | Pheochromocytoma | Parathyroid disease |
|---|---|---|---|
| MEN2A | 95% | 50% | 20% to 30% |
| FMTC | 100% | less than 1% | less than 1% |
| MEN2B | 100% | 50% | less than 1% |
MEN2A makes up about
MEN type 4
MEN4 is the newest identified form of MEN. It’s not clear how common it is due to
- parathyroid tumors
- pituitary gland tumors
- pancreatic tumors
- adrenal gland tumors
MEN is caused by genetic mutations passed through families. These mutations can also occasionally develop sporadically with no known family history.
Associated mutations include:
Symptoms of MEN depend on which types of tumors you develop.
Parathyroid tumors
Parathyroid tumors can lead to hypercalcemia, which is high calcium levels in your blood.
- muscle weakness
- body aches and pains
- tiredness
- excessive thirst
- excessive urination
- depression
- kidney stones
- constipation and other digestive problems
Other symptoms might include:
- stomach ulcers
- acid reflux
- abdominal pain
- frequent diarrhea
- low blood glucose
- enlarged and swollen hands and feet
Medullary thyroid carcinoma symptoms
MTC usually initially causes a lump and swelling in the front of your neck over your thyroid gland. If the tumor grows large, you might develop:
- hoarseness
- trouble swallowing
- breathing problems
Pheochromocytoma
Pheochromocytomas may not cause noticeable symptoms.
MEN complications depend on the types of tumors that develop and the type of gene mutation present.
Almost everybody with MEN1 develops parathyroid tumors.
For people with MEN1, gastrointestinal tumors with more than a 10%
| Tumor type | Lifetime risk | Symptoms |
|---|---|---|
| gastrinoma | less than 70% | • stomach ulcers • esophagitis • diarrhea • abdominal pain • weight loss |
| nonfunctioning gastrointestinal tumors | 20% to 55% | • symptoms related to compression • abdominal pain • jaundice • weight loss |
| insulinoma | 10% | problems with blood sugar levels |
People with MEN1 also have a high risk of the following pituitary tumors.
| Tumor type | Lifetime risk | Potential symptoms |
|---|---|---|
| prolactinoma | 20% | • infertility • milk production • hypogonadism |
| somatotropinoma | 10% | • increased sweating • bony overgrowth in face • enlargement of hands and feet |
| corticotropinoma | less than 5% | • weight gain • high blood pressure • flushing • easy bruising or bleeding • high blood sugar |
Almost everybody with MEN2 eventually develops MTC. People with high-risk genetic variants have a high risk of developing thyroid cancer that spreads to distant tissue if not treated promptly.
It’s a good idea to speak with your child’s doctor about the best screening schedule and treatment options if you have a known family history of MEN.
If you’ve previously been diagnosed with MEN, it’s important to see your doctor if you notice potential symptoms of a tumor in one of your glands.
Your doctor may arrive at a
- two or more MEN1-associated tumors
- a MEN1-related tumor and a child, sibling, or parent who has also received a MEN1 diagnosis
- an associated MEN1 mutation found with a genetic test
MEN2 is primarily diagnosed with the identification of an associated RET gene mutation. A doctor may diagnose MEN2 if you have MTC as well as pheochromocytoma or parathyroid disease.
You might receive a variety of tests to diagnose tumors and look for hormonal imbalances, such as:
MEN doesn’t have a cure so treatment aims to treat tumors and other associated conditions before or after they occur. You might receive:
- medications to correct high hormone levels
- surgery to remove all or part of the affected gland
- replacement hormone therapy if glands like your adrenal glands or thyroid glands are removed
- other cancer treatments like chemotherapy or radiation therapy
The life expectancy for people with MEN varies significantly depending on which tumors develop. Some people might only ever have mild disease while others may pass away in childhood.
People with MEN1 typically have an onset of symptoms between
People with MEN2B often have a
There’s no known way to prevent MEN since these conditions are caused by gene mutations present from birth. You can maximize your outlook by following your doctor’s screening and treatment guidance. For example, children at a high risk of thyroid cancer early in life may need their thyroid gland removed.
MEN is a group of cancer syndromes associated with a very high risk of developing tumors that develop in certain glands. Common tumors associated with these conditions include thyroid tumors, parathyroid tumors, adrenal gland tumors, and gastrointestinal tumors.
It’s important to follow your doctor’s instructions if you or your child has MEN. Your doctor can recommend how often you should be screened for tumors and how to best treat these tumors if they appear.