Multiple endocrine adenoma refers to three different conditions characterized by tumors in the endocrine system (a network of glands responsible for producing hormones).
The term “multiple endocrine neoplasia”, or MEN, is more commonly used in medical circles. The variants of MEN are known as Type 1 (Wermer syndrome), Type 2A and Type 2B (Sipple’s syndrome).
Each type is distinguished by the pattern in which the tumors occur. The tumors can be benign or malignant, and may appear at different times in a patient’s life. The term MEN applies specifically when two or more glands are affected, although the presence of multiple tumors does not automatically indicate MEN.
In MEN, there is a genetic mutation that stimulates cell over-production in the affected glands. Types 2A and 2B are caused by the same mutation, but a different gene is responsible for Type 1.
MEN is generally inherited as an autosomal dominant disorder. This means that only one parent has to have the disease trait to pass it on to their offspring.
The syndrome can occur at any age and affects men and women equally. Many cases have been accompanied or preceded by other endocrine tumors, as well as Zollinger-Ellison Syndrome (gastrinoma) and medullary thyroid carcinoma.
Signs and Symptoms
The most common symptom of MEN 1 is hyperparathyroidism, or overgrowth of the parathyroid glands. The thyroid itself is rarely affected. The symptoms usually appear before age 40 in people with the MEN 1 gene. Frequent ulcers, kidney stones, weak bones, pancreatic tumors, and nervous system depression are also common symptoms.
MEN 2A AND 2B
These variants are mainly characterized by pheochromocytoma, a tumor in the adrenal gland medulla, and medullary thyroid cancer (MTC). The latter is present in 100% of MEN Type 2 cases.
Other symptoms vary between Types 2A and 2B. MEN 2A patients tend to have hypertrophy or an increase in body size, and develop parathyroid tumors. In MEN 2B, common symptoms include swollen lips, enlarged colons, skeletal abnormalities, and tumors in the mucous membranes of facial organs. Most of these symptoms appear before age five.
The tumors associated with MEN Type 1 are usually benign, but those affecting the pancreas are likely to become cancerous. In such cases, the cancer can spread to the liver and other organs, lowering the chances of survival. Recovery can also be hampered by accompanying conditions such as low blood sugar, peptic ulcer disease, and pituitary dysfunction.
MEN Type 2 has a poorer prognosis because of the associated thyroid cancer. MTC is very aggressive and can easily spread to other organs. If left untreated, it can become fatal within weeks or days.
Since the disease is genetic, the best form of preventative care is cancer screening. If you or a close relative has developed MEN, you should have yourself and your children screened for the mutated genes. This screening can help detect tumors early and improve chances of recovery.
Diagnosis and Staging
Standard forms of diagnosis are used to determine individual symptoms, but gene testing will be needed to confirm the syndrome. Often, the first line of tests involves testing for abnormal hormone production. Commonly tested hormones include gastrin, glucagon, and parathyroid hormone. Tumors are usually detected by magnetic resonance imaging (MRI) and CT scans.
Additional diagnostic information is obtained via biopsies (a surgical procedure in which tissues are extracted). The biopsied tissue is sent to a laboratory for microscopic evaluation.
For both types of multiple endocrine adenoma, the treatment of choice is usually surgical removal of the affected gland/s. Children with the MEN 2 gene should have the thyroid and surrounding lymph nodes removed before age 5. However, removing the parathyroid gland, which controls calcium production, can cause bone problems following the surgery. If the tumor is benign and confined to the pituitary, it may be treated instead with a drug called bromocriptine.
Additional medications are also given to regulate the acid production of some tumors, reducing the risk of ulcers. Hormone replacement therapy is usually given to replace the function of the removed glands. Screening of family members is also highly recommended, so that early steps can be taken for those found to be at risk.