Multiple endocrine neoplasia (MEN) syndromes are a group of rare, inherited disorders characterized by the development of tumors in multiple endocrine glands.
These tumors can be benign or malignant and often result in overproduction of hormones, leading to various symptoms and complications.
Learn more about MEN syndromes, including their definition, types, causes, symptoms, diagnosis, treatment, and potential risks and complications.
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Our endocrine surgeons in St. Louis specialize in procedures for thyroid, parathyroid, and adrenal gland problems. We see patients at Barnes-Jewish Hospital, one of the top hospitals in the nation, as well as convenient locations around St. Louis.
What are multiple endocrine neoplasia (MEN) syndromes?
MEN syndromes are genetic disorders that cause the development of tumors in multiple endocrine glands.
There are three main types of MEN syndromes: MEN1, MEN2A, and MEN2B, each with distinct characteristics and affected glands.
Types of MEN syndromes
MEN1 (Wermer syndrome)
- Affected glands: Parathyroid glands, pancreas, and pituitary gland.
- Common tumors: Parathyroid adenomas, pancreatic islet cell tumors, and pituitary adenomas.
- Hormone abnormalities: Hyperparathyroidism, gastrinomas, insulinomas, prolactinomas.
MEN2A (Sipple syndrome)
- Affected glands: Thyroid, parathyroid glands, and adrenal glands.
- Common tumors: Medullary thyroid carcinoma, pheochromocytomas, and parathyroid adenomas.
- Hormone abnormalities: Hyperparathyroidism, excess catecholamines.
MEN2B
- Affected glands: Thyroid and adrenal glands; presence of mucosal neuromas and marfanoid habitus.
- Common tumors: Medullary thyroid carcinoma and pheochromocytomas.
- Unique features: Mucosal neuromas, marfanoid body habitus, gastrointestinal issues.
Did you know?
Researchers at WashU Medicine identified the genetic mutations responsible for MEN syndromes and advanced a preventive procedure that includes surgical removal of the thyroid gland.
Our experts are still making new discoveries today to improve treatment for MEN syndromes.
Causes of MEN syndromes
Genetic mutations
- MEN1: Caused by mutations in the MEN1 gene (menin).
- MEN2A and MEN2B: Caused by mutations in the RET proto-oncogene.
Inheritance pattern
- Autosomal dominant: MEN syndromes are inherited in an autosomal dominant pattern, meaning a single copy of the mutated gene from one parent is sufficient to cause the disorder.
Symptoms of MEN syndromes
MEN1
- Hyperparathyroidism: Kidney stones, bone pain, fatigue, and weakness due to high calcium levels.
- Pancreatic islet cell tumors: Hypoglycemia (insulinomas), peptic ulcers (gastrinomas), diarrhea (VIPomas).
- Pituitary adenomas: Headaches, vision problems, hormonal imbalances (excess prolactin).
MEN2A
- Medullary thyroid carcinoma: Neck mass, difficulty swallowing, hoarseness.
- Pheochromocytomas: High blood pressure, rapid heartbeat, sweating, headaches.
- Hyperparathyroidism: Similar symptoms to MEN1.
MEN2B
- Medullary thyroid carcinoma: Similar symptoms to MEN2A.
- Pheochromocytomas: Similar symptoms to MEN2A.
- Mucosal neuromas: Bumps on the lips, tongue, and lining of the mouth.
- Marfanoid habitus: Tall, thin body with long limbs and fingers.
- Gastrointestinal issues: Chronic constipation, diarrhea.
Learn more: Medullary thyroid carcinoma>>
Diagnosis of MEN syndromes
Medical history and physical examination
- Symptom assessment: Detailed inquiry about symptoms related to affected endocrine glands.
- Family history: Evaluation of family history to identify patterns of inherited endocrine disorders.
Laboratory tests
- Blood tests: Measurement of calcium, thyroid hormones, adrenal hormones, and other relevant markers.
- Hormone levels: Assessing hormone levels to identify abnormalities.
Imaging studies
- Ultrasound: Imaging of the thyroid, parathyroid, and adrenal glands.
- CT scan or MRI: Detailed imaging to visualize tumors in endocrine glands.
- Nuclear medicine scans: Specific scans to detect medullary thyroid carcinoma and pheochromocytomas.
Genetic testing
- Confirmation of diagnosis: Genetic testing to identify mutations in the MEN1 gene or the RET proto-oncogene.
- Family testing: Genetic testing of family members to identify carriers of the mutated gene and assess their risk of developing MEN syndromes.
Treatment of MEN syndromes
Surgical treatment
- Tumor removal: Surgical removal of tumors in the affected endocrine glands (e.g., parathyroidectomy, thyroidectomy, adrenalectomy).
- Preventive surgery: Prophylactic thyroidectomy for individuals with MEN2 syndromes carrying RET mutations to prevent medullary thyroid carcinoma.
Medical management
- Medications: Hormone replacement therapy for deficiencies due to gland removal and medications to control hormone overproduction (e.g., antihypertensives for pheochromocytomas).
- Monitoring: Regular follow-up to monitor hormone levels, tumor recurrence, and management of symptoms.
Lifestyle modifications
- Diet and nutrition: Maintaining a balanced diet to support overall health and address specific nutritional needs due to hormone imbalances.
- Regular exercise: Enhancing physical activity to improve overall well-being.
Supportive care
- Psychosocial support: Counseling and support groups to manage the emotional and psychological challenges associated with chronic illness and genetic disorders.
- Endocrine specialist care: Regular follow-ups with an endocrinologist or endocrine surgeon to monitor and manage the various aspects of MEN syndromes.
Potential risks and complications
Tumor-related complications
- Metastasis: Risk of malignant tumors spreading to other parts of the body.
- Organ dysfunction: Impaired function of affected organs due to hormone imbalances and tumor growth.
Surgical risks
- Infection: Risk of infection at the surgical site.
- Bleeding: Risk of bleeding during and after surgery.
- Nerve damage: Risk of nerve damage (e.g., vocal cord paralysis after thyroidectomy).
Long-term considerations
- Hormone management: Ongoing monitoring and management of hormone levels to ensure proper endocrine function.
- Familial risk: Genetic counseling for families considering having children to understand the risk of passing on MEN syndromes.
Multiple endocrine neoplasia (MEN) syndromes are complex genetic disorders requiring a multidisciplinary approach for effective management.
Early diagnosis, regular monitoring, surgical intervention, and medical management are crucial for improving outcomes and quality of life.
If you or a family member have been diagnosed with an MEN syndrome, consult with a specialized medical team to develop a personalized care plan tailored to your specific needs and circumstances.
