Multiple Endocrine Neoplasia Syndrome

Multiple Endocrine Neoplasia, also known as MEN, is a group of rare, inherited disorders that predispose patients to the development of tumors in multiple organs. These are rare conditions, affecting approximately 1 in 30,000 to 50,000 thousand people. Although they are rare disorders, it is important to identify patients with them. Since these conditions are inherited, it can affect multiple family members, and it can be passed down to children.

What are the types of Multiple Endocrine Neoplasia?

There are two broad types of Multiple Endocrine Neoplasia, type 1 and type 2. In MEN1, there is a predisposition to tumors of the parathyroid glands, which are located behind the thyroid gland, the anterior pituitary gland and neuroendocrine cells of the gastrointestinal system. MEN1 is caused by mutations in the MEN1 gene, located on chromosome 11.

MEN2 is subclassified into two distinct syndromes: type 2A and type 2B.

• MEN2A is characterized by medullary thyroid cancer, a rare type of thyroid cancer, pheochromocytoma, a rare tumor that usually starts in the cells of one of your adrenal glands, and primary parathyroid hyperplasia, which causes the enlargement of the parathyroid glands and is referred to as hyperparathyroidism. 
• MEN2B is characterized by medullary thyroid cancer, pheochromocytoma but not hyperparathyroidism. MEN2 is caused by mutations in the RET proto-oncogene, on chromosome 10.

Importantly, having MEN1 or MEN2 does not mean that you will have every feature seen in the disease. Some features, such as hyperparathyroidism in MEN 1 and medullary thyroid cancer in MEN2, will be present in just about everyone with the disorder. Other features do not occur as frequently but should be screened for at regular intervals.

Can I get screened for Multiple Endocrine Neoplasia?

Yes. Patients who have clinical findings that are seen in multiple endocrine neoplasia should undergo genetic testing. Also, patients who have first/second-degree relatives with MEN1/2 should also be tested. Genetic testing involves meeting with a genetics counselor, discussing pertinent medical information along with risks/benefits of genetic testing, undergoing testing (blood- or saliva-based testing) and reviewing results of testing. If you are found to have MEN type 1 or 2, we will discuss management/screening options as well.