Multiple endocrine neoplasia, type 1 (MEN 1)

Overview

Multiple endocrine neoplasia, type 1 (MEN 1) is a rare condition. It mainly causes tumors in the glands that make and release hormones. These are called the endocrine glands. The condition also can cause tumors in the small intestine and stomach. Another name for MEN 1 is Wermer's syndrome.

The endocrine gland tumors that form due to MEN 1 usually are not cancer. Most often, the tumors grow on the parathyroid glands, the pancreas and the pituitary gland. Some glands affected by MEN 1 also may release too many hormones. That can lead to other health concerns.

The extra hormones of MEN 1 can cause many symptoms. These symptoms may include tiredness, bone pain, broken bones, kidney stones, and ulcers in the stomach or intestines.

MEN 1 can't be cured. But regular testing can detect health concerns, and healthcare professionals can provide treatment as needed.

MEN 1 is an inherited condition. That means people who have a genetic change that causes MEN 1 can pass it on to their children.

Symptoms

Symptoms of multiple endocrine neoplasia, type 1 (MEN 1) can include the following:

  • Tiredness.
  • Bone pain or broken bones.
  • Kidney stones.
  • Ulcers in the stomach or intestines.
  • Stomach pain.
  • Muscle weakness.
  • Depression.
  • Acid reflux.
  • Frequent diarrhea.

Symptoms are caused by the release of too many hormones in the body.

Causes

Multiple endocrine neoplasia, type 1 (MEN 1) is caused by a change in the MEN1 gene. That gene controls how the body makes a protein called menin. Menin helps to keep cells in the body from growing and dividing too quickly.

Many different changes in the MEN1 gene can cause the MEN 1 condition to develop. People who have one of those genetic changes can pass it on to their children. Many people with a change in the MEN1 gene inherit it from a parent. But some people are the first in their family to have a new MEN1 gene change that doesn't come from a parent.

Risk factors

Risk factors for multiple endocrine neoplasia, type 1 (MEN 1) include the following:

  • Children with a parent who has a genetic change in the MEN1 gene are at risk of the MEN 1 condition. That's because these children have a 50% chance of having the same genetic change that causes MEN 1.
  • Parents and siblings of people who have a change in the MEN1 gene also are at risk. That's because they may have the same genetic change, even if they haven't had any symptoms of MEN 1.

Diagnosis

To find out if you have multiple endocrine neoplasia, type 1 (MEN 1), your healthcare professional starts by doing a physical exam. You also answer questions about your health history and family history. You may have a blood test and imaging tests, including the following:

  • Magnetic resonance imaging (MRI). An MRI uses a magnetic field and radio waves to make images of the organs and tissues in the body.
  • Computerized tomography (CT) scan. A CT scan combines a series of X-ray images taken from different angles. A computer then makes detailed pictures of the inside of the body.
  • Positron emission tomography (PET) scan. A PET scan uses a substance that releases low levels of radiation to help make images of changes taking place inside the body.
  • Nuclear medicine scans. These scans use liquid substances that give off low levels of radiation to help find tumors.
  • Endoscopic ultrasound of the pancreas and other scans. An endoscopic ultrasound uses sound waves to make images of the digestive tract and other nearby organs and tissues.

Genetic testing may help find out whether someone has a genetic change that causes MEN 1. If so, that person's children are at risk of having the same genetic change and getting MEN 1. Parents and siblings also are at risk of having the genetic change that causes MEN 1.

If no related genetic changes are found in family members, then family members don't need more screening tests. But genetic testing cannot find all the genetic changes that can cause MEN 1. If genetic testing doesn't confirm MEN 1, but it's likely that a person has it, more testing is needed. That person, as well as family members, still needs follow-up healthcare checkups with blood tests and imaging tests.

Treatment

With MEN 1, tumors can grow on the parathyroid glands, the pancreas and the pituitary gland. That can lead to various conditions, all of which can be treated. These conditions and treatments may include:

  • Pituitary tumors. These types of tumors may be treated with surgery or medicines. Rarely, radiation therapy is used.
  • Hyperparathyroidism. Surgery to remove most of the parathyroid glands is the typical treatment for too much parathyroid hormone.
  • Neuroendocrine tumors. These are tumors that form in specialized cells called neuroendocrine cells. With MEN 1, they're in the pancreas or small intestine. Treatment depends on the type and size of the tumor.
  • Hypoglycemic syndrome. This condition happens when tumors in the pancreas called insulinomas make too much insulin hormone. Too much insulin causes low levels of blood sugar that can be life-threatening. Treatment often involves surgery. Part of the pancreas may need to be removed too.
  • Zollinger-Ellison syndrome (ZES). ZES can result in tumors called gastrinomas that make too much stomach acid. This leads to ulcers and diarrhea. Healthcare professionals may prescribe medicine or try to remove the tumors with surgery.
  • Other pancreatic neuroendocrine tumors. These tumors sometimes make other hormones that can cause health issues. Treatment of these types of tumors may involve medicine or surgery. Another treatment called ablation can be done to destroy irregular tissue that may be present.
  • Metastatic neuroendocrine tumors. Tumors that spread are called metastatic tumors. Sometimes with MEN 1, tumors spread to the lymph nodes or liver. They may be treated with surgery. Surgery options include liver surgery or different types of ablation.

    Radiofrequency ablation uses high-frequency energy that passes through a needle. The energy causes the surrounding tissue to heat up, killing the nearby cells. Cryoablation involves freezing tumors. And chemoembolization involves injecting strong chemotherapy medicines directly into the liver. When surgery is not an option, healthcare professionals may use other forms of chemotherapy or hormone-based treatments.

  • Adrenal tumors. Most of these tumors can be watched with tests over time and not treated. But if the tumors make hormones or they're large and thought to be cancerous, healthcare professionals recommend removing them. Often, the tumors can be removed with surgery that involves small incisions. This is known as minimally invasive surgery.
  • Carcinoid tumors. These slow-growing tumors in people with MEN 1 can form in the lungs, thymus gland and gastrointestinal tract. Surgeons remove these tumors when they haven't spread to other areas. Healthcare professionals may use chemotherapy, radiation therapy or hormone-based therapy for advanced carcinoid tumors.

Preparing for an appointment

You may start by seeing your primary healthcare professional. Then you may be referred to a doctor called an endocrinologist who treats conditions related to hormones. You also may be referred to a genetic counselor.

Here's some information to help you get ready for your appointment.

What you can do

When you make the appointment, ask if there's anything you need to do ahead of time. For example, you may be told not eat or drink anything except water for an amount of time before a test. This is called fasting. You also can make a list of:

  • Your symptoms. Include any that don't seem related to the reason for your appointment.
  • Key personal information. Include major stresses, recent life changes and family medical history.
  • All medicines, vitamins or other supplements you take, including the doses.
  • Questions to ask your healthcare professional.

Take a family member or friend along if you can. This person can help you remember the information you're given.

For MEN 1, some basic questions to ask your healthcare professional include:

  • What's likely causing my symptoms?
  • Other than the most likely cause, what are other possible causes for my symptoms?
  • What tests do I need?
  • Is my condition likely short-term or long-term?
  • What's the best course of action?
  • What are the alternatives to the main treatment you're suggesting?
  • I have other health conditions. How can I best manage them together?
  • Are there restrictions I need to follow?
  • Should I see a specialist?
  • Are there brochures or other printed material I can have? What websites do you recommend?

Feel free to ask any other questions that you think of.

What to expect from your doctor

Your healthcare professional is likely to ask you questions such as:

  • Does anyone in your family have MEN 1?
  • Have you or any family members been tested for changes in the MEN1 gene?
  • If you have symptoms, when did they start?
  • Are your symptoms ongoing or do they happen once in a while?
  • How severe are your symptoms?
  • What, if anything, seems to make your symptoms better?
  • What, if anything, seems to make your symptoms worse?

What you can do in the meantime

If you have symptoms, try not to do anything that seems to make them worse.


Content From Mayo Clinic Updated: 10/03/2024
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