Multiple Endocrine Neoplasia Type 2 (MEN2)
Multiple Endocrine Neoplasia type 2 (MEN2) is a rare inherited condition that increases the risk of developing certain hormone-producing tumours.
Overview
Multiple Endocrine Neoplasia type 2 (MEN2) is a rare inherited condition that increases the risk of developing certain hormone-producing tumours. MEN2 most commonly involves the thyroid gland (a type of thyroid cancer called medullary thyroid cancer), the adrenal glands (phaeochromocytoma), and sometimes the parathyroid glands. Early diagnosis is important because medullary thyroid cancer can often be prevented or treated more effectively when identified early.
Causes and Genetics
MEN2 and MEN3 (also called MEN2B) are caused by changes (mutations) in the RET gene. The RET gene affects cell growth and signalling. MEN2 and MEN3 are inherited in an autosomal dominant pattern, meaning a person only needs one altered copy of the gene to have the condition. An affected person has a 50% chance of passing it on to each child. The specific RET mutation influences the pattern of tumours and the recommended screening and treatment plan.
Symptoms and Features
Symptoms depend on which glands are affected. Many people are diagnosed through genetic testing before symptoms appear.
Characteristic Symptoms and Features
- Thyroid (medullary thyroid cancer): a lump in the neck, hoarse voice, difficulty swallowing, or no symptoms early on
- Adrenal (phaeochromocytoma): episodes of headaches, sweating, palpitations, tremor and high blood pressure (these can come and go)
- Parathyroid (more common in MEN2A): raised calcium levels which may cause kidney stones, constipation, thirst, frequent urination, tiredness and bone pain
Other Associated Symptoms and Features
- MEN3 (MEN2B) may also be associated with a tall, slim body build, joint looseness, and non-cancerous nerve lumps on the lips and tongue (mucosal neuromas), as well as bowel symptoms such as constipation or diarrhoea
Treatment
Lifelong monitoring is important, including regular blood and urine tests and scans where appropriate.
Research and Future Directions
Ongoing research is improving personalised care based on the exact RET mutation and refining the safest timing for screening and preventative surgery. Targeted cancer treatments that block RET signalling are also being used and studied for advanced medullary thyroid cancer, helping to improve outcomes for some patients.