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General: The pituitary gland is a pea-sized gland that is located at the base of the brain. Many experts consider the pituitary gland to be the most important part of the endocrine system because it secretes hormones that regulate the functions of many other endocrine glands. The pituitary gland secretes growth hormone (GH), which regulates bone and tissue growth. It also helps maintain a healthy balance of muscle and fat tissue in the body. The gland secretes anti-diuretic hormone (ADH), which controls urine production and manages the water balance in the body. Thyroid-stimulating hormone (TSH) is also produced. This hormone signals the thyroid gland to secrete hormones that regulate the body's metabolism. The pituitary gland also secretes luteinizing hormone (LH), which regulates testosterone production in males and estrogen production in females. Follicle-stimulating hormone (FSH) is produced as well. This hormone signals sperm production in males and egg development and ovulation in females. Adrenocorticotropic hormone (ACTH) is produced to stimulate the adrenal glands to produce hormones, such as cortisol. The adrenal hormones help the body cope with stress and they regulate bodily functions, such as blood pressure. Prolactin is secreted to regulate the development of breasts and breast milk in females. Acromegaly: Acromegaly is a rare hormonal disorder that occurs when the pituitary gland secretes too much growth hormone. As a result, the bones in the hands, feet, and face increase in size. If left untreated, acromegaly may be life threatening. Serious complications may include high blood pressure, heart disease, and spinal cord compression. The condition usually occurs in middle-aged adults. However, children may also develop acromegaly. When children produce too much growth hormone, the condition is called gigantism. These children have large bones and are abnormally tall. Acromegaly is usually caused by a noncancerous tumor of the pituitary gland, which secretes too much growth hormone. Acromegaly may also develop in patients who have tumors in other parts of the body, such as the pancreas, adrenal gland, or lungs. In rare cases, these tumors may secrete growth hormone-releasing hormone (GH-RH), which signals the pituitary gland to release more growth hormone. Symptoms of acromegaly develop gradually over many years. The most common symptom of acromegaly is enlarged hands and feet. It may also lead to gradual changes in the shape of the face, such as enlarged nose, thickened lips, increased gaps between the teeth, or protruding lower jaw or brow. Other symptoms may include coarse or oily skin, increased sweating and body odor, fatigue, muscle weakness, small outgrowths of skin tissue (skin tags), deepened voice, impaired vision, severe snoring, headaches, enlarged tongue, joint pain, limited joint mobility, increased chest size, enlarged organs (such as heart, kidneys, and spleen), irregular menstrual cycle in women, and erectile dysfunction in men. Some of the symptoms of acromegaly, such as headaches and impaired vision, occur because the tumor is pressing on the brain. The standard diagnostic test for acromegaly is a growth hormone suppression test. During the procedure, a sample of blood is taken from the patient before and after he/she drinks a special fluid made with sugar (glucose). In healthy individuals, the sugar will cause the levels of growth hormone to decrease. However, patients with acromegaly will have high levels of growth hormone even after consuming sugar. Imaging studies, such as computerized tomography (CT) scans or magnetic resonance imaging (MRI) scans, may also be performed. CT scans and MRIs are noninvasive tests that can produce images of the pituitary gland. They can help healthcare providers locate tumors on the gland. Patients with acromegaly receive treatments to reduce the amount of growth hormone produced. Surgery may be performed to remove tumors that are causing the disorder. In most cases, the surgery can be performed during a procedure called transsphenoidal surgery. The surgeon removes the pituitary gland through the nose. Once the tumor is removed, the level of growth hormone in the body will return to normal. Sometimes the surgeon is unable to remove the entire tumor. In such cases, radiation therapy is often recommended to remove the rest of the tumor. Patients may also receive injections of man-made hormones, such as octreotide (Sandostatin ® or Sandostatin LAR ®), to reduce the amount of growth hormone that is released. Patients typically receive a short-acting injection to determine if the medication is safe and effective in the patient. If it is successful, patients will receive injections once a month for life. If other treatments are unsuccessful, patients may take medications called growth hormone antagonists, which block the effect of growth hormone on body tissues. Medications, such as pegvisoman (Somavert ®), are injected into the patient. Although this treatment reduces symptoms, it does not lower the amount of growth hormone in the blood, and it does not reduce the size of the tumor. Hypopituitarism: Hypopituitarism is a hormonal disorder that occurs when the pituitary gland does not secrete enough of one or more hormones. Depending on the type and severity of the hormone deficiency, any number of the body's functions may be affected, including growth, blood pressure, and reproduction. The condition occurs when the pituitary gland becomes injured or damaged. Several conditions, including head injuries, brain surgery, brain tumors, radiation therapy, inflammation, stroke, brain infections (such as meningitis), tuberculosis, blood loss during childbirth, genetic mutations, and diseases (such as sarcoidosis or histiocytosis), may lead to hypopituitarism. Signs and symptoms of hypopituitarism vary depending on which hormone is deficient. Symptoms of adrenocorticotropic (ACT) hormone deficiency may include fatigue, low blood pressure, weight loss, weakness, depression, nausea, and vomiting. Symptoms of thyroid-stimulating hormone (TSH) deficiency may include constipation, weight gain, sensitivity to cold, decreased energy, and muscle weakness or aching. Symptoms of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) deficiency include irregular or stopped menstrual periods and infertility in women. Men may experience loss of body and facial hair, weakness, decreased libido, erectile dysfunction, and infertility. Symptoms of growth hormone deficiency in children may include short height, excessive fat around the waist and in the face, and poor overall growth. In adults, symptoms may include fatigue, decreased strength and exercise tolerance, weight gain, decreased muscle mass, and feelings of anxiety or depression. Symptoms of prolactin deficiency in women may include lack of milk production, fatigue, and loss of underarm and pubic hair. Prolactin deficiency has no known adverse effects in men and no symptoms are seen. Symptoms of anti-diuretic hormone (ADH) deficiency may include increased thirst and urination. Blood tests are used to diagnose hypopituitarism. Patients with low or non-existent levels of one or more hormones have the condition. In addition, imaging studies, including CT scans and MRI scans, may be used to detect tumors or abnormalities in the pituitary gland. Treating the underlying cause of hypopituitarism may lead to a partial or complete recovery. If a tumor is causing symptoms, it is usually surgically removed. If surgery is not possible or if only part of the tumor can be removed, radiation therapy may also be necessary. Some patients may require hormone replacement therapy. Corticosteroids, such as hydrocortisone or prednisone, may be taken by mouth to replace the adrenal hormones that are not being produced because of an ACTH deficiency. A man-made hormone called levothyroxine (Levoxyl ® or Synthroid ®) may be taken to replace low levels of thyroid hormones caused by TSH deficiencies. Patients with FSH or LH deficiencies may receive man-made sex hormones. Females receive a combination of estrogen and progesterone, while males receive testosterone. Patients with ADH deficiency may take a man-made hormone, called desmopresin (DDAVP ®), by mouth or nasal spray. Patients with low levels of GH may receive injections with a man-made growth hormone called somatropin (Genotropin ®).
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