This is a rare genetic condition characterized by the presence of non-cancerous tumors that can develop in various glands of the body although in some cases, the benign tumor can become cancerous. The hormones produced by the endocrine system help regulate the metabolism of various essential functions including regulating body temperature, blood pressure, the growth and regulating heart rate. Among the affected individuals with MEN type 1, the benign tumors can develop in the multiple endocrine glands commonly involving the parathyroid, pancreas and the pituitary glands. As the result of the tumor growths, the glands secrete large quantity of various hormones causing their associated symptoms.
Causes
This can occur as the result of a genetic mutation in the MEN1 gene. This condition can be inherited in an autosomal dominant trait or as the result of a new genetic mutation. An autosomal dominant genetic disease occurs when a single copy of the defective gene inherited from the parents is sufficient to cause this condition.
Symptoms
There are more than 20 different forms of endocrine and non-endocrine tumors that been associated with this condition. However, the symptoms that occur can be highly variable and not all affected people tend to develop all the associated symptoms. In around 90% of the cases, the parathyroid glands become affected. As the result of the excess production of parathyroid hormone, too much calcium can accumulate in the blood (hypercalcemia) which can cause kidney stones or kidney damage. In around 40% of the cases, multiple gastrinomas can occur which are the benign tumors that secrete gastrin which can present problems such as abdominal pain, esophageal reflux and peptic ulcers. Gastrinomas that arise from islet cells has the potential to become cancerous spreading to other parts of the body (metastasize). In around 25% of the cases, the benign tumors of the pituitary gland can occur which is responsible for the production of different types of hormones. In around 10-15% of the cases, the slow growing carcinoid tumors can develop in the stomach and the bronchial tubes. Other forms of tumors include the insulinoma which is the benign tumor that secretes insulin which can cause low blood sugar. In rare cases, the affected individual can also develop a VIPoma, a tumor that produces the vasoactive intestinal peptide which can cause chronic water diarrhea. The non-endocrine benign tumors can also develop and the most common are the lipoma which can occur under the surface of the skin.
Diagnosis
The diagnosis is based on the identification of at least two of three characteristic endocrine tumors of this condition. Various tests can also help identify the high levels of hormones that are associated with the tumor. The imaging tests may also be necessary to detect the location and determine the size of the tumors.
Treatment
The treatment can include a surgery to remove the tumor, radiation or chemotherapy to destroy the tumors and medications to stabilize the effects of excess hormones produced by the body. Genetic counseling in some cases may be beneficial for the affected individual and their family members.
References
https://rarediseases.org/rare-diseases/multiple-endocrine-neoplasia-type-1/
http://www.cancer.net/cancer-types/multiple-endocrine-neoplasia-type-1
