MEN Syndromes

Condition Overview

Multiple Endocrine Neoplasia (MEN) syndromes are a group of hereditary disorders that cause tumors in multiple endocrine glands. These syndromes are divided into several types, the most common being MEN type 1 (MEN1) and MEN type 2 (MEN2). Each type is characterized by specific patterns of endocrine tumors. Because they most commonly involve the thyroid and parathyroid glands, MEN1 and MEN2 are discussed here.

• MEN Type 1 (MEN1): This syndrome is caused by mutations in the MEN1 gene and typically involves tumors in the parathyroid glands, pancreas, and pituitary gland. Patients with MEN1 often develop hyperparathyroidism due to parathyroid hyperplasia, leading to hypercalcemia. Pancreatic tumors can include gastrinomas, insulinomas, and other neuroendocrine tumors. Pituitary tumors commonly involve prolactinomas or growth hormone-secreting tumors.
• MEN Type 2 (MEN2): This syndrome is caused by mutations in the RET proto-oncogene and is further subdivided into MEN2A, MEN2B, and familial medullary thyroid carcinoma (FMTC). MEN2A is characterized by medullary thyroid carcinoma (MTC), pheochromocytomas, and parathyroid hyperplasia. MEN2B includes MTC, pheochromocytomas, mucosal neuromas, and a marfanoid habitus. FMTC is primarily associated with MTC without other endocrine tumors.
• MEN Type 4 (MEN4): A less well-characterized syndrome, MEN4 patients are noted to have parathyroid hyperplasia. This can most often be recognized by cystic changes to the parathyroid glands.

Patients with MEN syndromes may present with a variety of symptoms depending on the affected glands and the types of hormones being overproduced. These can include hypercalcemia, hypoglycemia, gastrointestinal symptoms, high blood pressure, and neurological symptoms.

Diagnosis involves genetic testing to identify mutations in the MEN1 or RET genes, along with biochemical tests to measure hormone levels and imaging studies to locate tumors. Early diagnosis and regular screening are crucial for managing MEN syndromes effectively.

Treatment Options

1. Parathyroidectomy
   • Description: This surgical procedure involves the removal of one or more overactive parathyroid glands. It is commonly performed in patients with MEN1 who develop hyperparathyroidism due to parathyroid adenomas. Usually, more than 1 parathyroid gland needs to be removed if MEN1 is known to the cause of the hyperparathyroidism. Reoperative parathyroid surgery is much more challening than first time surgery.
   • Indications: Hyperparathyroidism with hypercalcemia, symptomatic patients, multiple or recurrent parathyroid tumors.
2. Total Thyroidectomy
   • Description: Total thyroidectomy involves the complete removal of the thyroid gland and is the standard treatment for medullary thyroid carcinoma (MTC) in patients with MEN2. Prophylactic thyroidectomy is often recommended for individuals with known RET mutations to prevent the development of MTC.
   • Indications: Diagnosed or high-risk MTC, prophylactic surgery in RET mutation carriers. This can sometimes be required in children, and the specific mutation plays a role in determining when to do surgery. Dr Russell and the team of anesthesiologists and endocrinologists with whom he works are well-versed in all of the latest techniques and offer a unique perspective that may be beneficial in improving the postoperative quality of life in pediatric patients who require prophylactic thyroidectomy. This can often be done without a scar.
3. Central Neck Dissection (CND)
   • Description: CND is a surgical procedure that involves the removal of lymph nodes and other tissues in the central compartment of the neck. This may be performed in conjunction with thyroidectomy in patients with MTC to manage lymph node metastasis. Because CND is among the most challenging surgical procedures that are required in endocrine surgery, it is especially critical to have an experienced surgeon.
   • Indications: MTC with central compartment lymph node involvement, recurrent or persistent MTC.

Management of MEN syndromes requires a multidisciplinary approach involving endocrinologists, geneticists, surgeons, and oncologists. Regular monitoring and timely intervention are essential to manage hormone overproduction, prevent complications, and improve patient outcomes. Having an experienced team such as that at the Russell Center ensures that you will have access to the widest range of options for your MEN syndrome.