hormonal and metabolic disorders
Multiple Endocrine Neoplasia Syndromes (MEN)
Types of MEN Syndromes
Multiple endocrine neoplasia syndromes occur in four patterns, called MEN 1, MEN 2A, MEN 2B, and MEN 4, although the types occasionally overlap. People with multiple endocrine neoplasia type 1 develop tumors, or excessive growth and activity, of two or more of the following glands: The parathyroid glands (the small glands located next to the thyroid gland in the base of the neck) The pancreas The Overview of the Pituitary Gland None The Overview of the Adrenal Glands (less often affected) ( Hyperparathyroidism ). The excess Many (30 to 90%) of people with MEN type 1 also develop tumors of the hormone-producing cells (islet cells) of the pancreas (also called Overview of Pancreatic Endocrine Tumors ). More than half of islet cell tumors produce excessive gastrin, which stimulates the stomach to overproduce acid. People with tumors that produce gastrin generally develop Peptic Ulcer Disease that often bleed, develop holes (perforate), and leak stomach contents into the abdomen, or block the stomach. The high acid levels commonly interfere with the activity of enzymes from the pancreas, resulting in diarrhea and fatty, smelly stools (steatorrhea). Some of these tumors produce high levels of Some of the islet cell tumors are cancerous and able to spread (metastasize) to other areas of the body. In people who have MEN type 1, cancerous islet cell tumors tend to grow more slowly than cancerous islet cell tumors that develop in people who do not have this condition. Some people with MEN type 1 develop pituitary gland tumors. Some of these tumors produce the hormone prolactin, causing menstrual abnormalities and often breast secretions ( Prolactinoma ) in women who are not nursing and decreased sexual desire and In some people with MEN type 1, tumors or excessive growth and activity of the adrenal glands develop. A small percentage of people develop a different type of tumor, known as Carcinoid Tumors and Carcinoid Syndrome . Some people also develop noncancerous growths just below the skin. Women with MEN type 1 may be at higher risk of Breast Cancer . People with multiple endocrine neoplasia type 2A develop tumors or excessive growth and activity in two or three of the following glands: The Overview of the Thyroid Gland None The Overview of the Adrenal Glands None The parathyroid glands Occasionally, an itchy skin condition called cutaneous lichen amyloidosis occurs in people with MEN type 2A. Hirschsprung Disease is present in 2 to 5% of people with MEN type 2A. Almost everyone with MEN type 2A develops Medullary thyroid cancer . About 40 to 50% develop certain tumors of the adrenal glands ( cause increased levels of calcium in the blood. The increased calcium often causes no symptoms but leads to Stones in the Urinary Tract in about 25% of people. Multiple endocrine neoplasia type 2B can consist of Medullary thyroid cancer None Pheochromocytoma None Growths around nerves (neuromas) Many people with MEN type 2B have no family history of it. In these people, the condition is the result of a new gene defect (genetic mutation). The Medullary thyroid cancer that occurs in MEN type 2B tends to develop at an early age and has been found in infants as young as 3 months of age. The medullary thyroid tumors in MEN type 2B grow faster and spread more rapidly than those in MEN type 2A. Most people with MEN type 2B develop neuromas in their mucous membranes. The neuromas appear as glistening bumps around the lips, tongue, and lining of the mouth. Neuromas may also occur on the eyelids and glistening surfaces of the eyes, including the conjunctiva and cornea. The eyelids and lips may thicken, and the lips may turn inside out (become everted). Digestive tract abnormalities cause constipation and diarrhea. Occasionally, the colon develops large, dilated loops (megacolon). These abnormalities probably result from neuromas growing on the intestinal nerves. People with MEN type 2B often develop spinal abnormalities, especially curvature of the spine. They may also have abnormalities of the bones of the skull, feet, and thighs. Most people with MEN 2B have long limbs and loose joints and appear quite thin. Some of these abnormalities are similar to those that occur in Marfan Syndrome . MEN type 4 is similar to MEN type 1 but is due to an abnormality in a different gene and is much less common. People with MEN type 4 develop tumors in their Parathyroid glands Pancreas Pituitary gland In people with MEN type 4, usually only one parathyroid gland is affected. In MEN type 1 , several parathyroid glands are affected. Also, people with MEN type 4 do not have the same skin symptoms as people with MEN type 1 do. 