Definition and Overview
The pituitary gland is a pea-sized gland found at the base of the brain. It is often called the master gland. It produces several hormones that are crucial for good health and well-being. These include prolactin and luteinising hormone. The former stimulates breast milk production after childbirth. The latter, on the other hand, stimulates ovulation in women and testosterone production in men.
The pituitary gland also produces hormones that stimulate the production of other hormones. These include adrenocorticotropin (ACTH) and thyroid-stimulating (THS) hormones. ACTH stimulates the adrenal gland to produce cortisol. THS, on the other hand, stimulates the thyroid gland to produce hormones that regulate metabolism.
The pituitary gland can malfunction. The most common cause are abnormal growths. Less common causes are injuries to the gland and side effects of certain medications. These prevent the gland from producing enough hormones the body needs to work properly.
Causes of Condition
Pituitary gland disorders can be caused by the following:
Tumours - Tumours are the most common cause of pituitary gland disorders. They can develop in or near the gland. Most of them are non-cancerous. This means they do not spread to other parts of the body. However, they can put undue pressure on the gland and cause it to malfunction.
Cancer treatment - Radiation therapy and chemotherapy that are used to treat pituitary tumours can also cause the gland to malfunction.
Damage due to surgery or traumatic injury to the head or brain.
Damage due to certain infections, such as meningitis, tuberculosis, and encephalitis.
Disorders that cause the immune system to attack the pituitary gland.
Below is a list of pituitary disorders with their corresponding signs and symptoms:
Acromegaly - This disorder develops when a person has too much growth hormone in his or her body. Its signs include unusually large bones in the feet, hands, and face. Patients also have coarse facial features and widely spaced teeth. Other symptoms include muscle weakness, profuse sweating, and thickened skin.
Cushing syndrome - This disorder is marked by high levels of cortisol. It often results in depression, irritability, and anxiety. It also makes patients more prone to infections. In women, the disorder results in irregular menstrual periods. In men, it can lead to erectile dysfunction and decreased fertility. In children, the disorder can cause obesity and delayed growth.
Hyperprolactinemia - This disorder is marked by high levels of prolactin. This hormone stimulates breast milk production after childbirth. Its most common sign is a milky discharge from the breast even when the patient is not pregnant or breastfeeding. It can also result in vaginal dryness, irregular menstrual periods, and excessive body and facial hair.
Hypopituitarism - This is a rare disorder characterised by the lack or inadequate supply of certain hormones. Its symptoms include anaemia, infertility, fatigue, and weight loss. It can also prevent women from producing milk when they are pregnant or breastfeeding.
Who to See and Types of Treatments Available
Disorders of the pituitary gland are treated by endocrinologists. These are doctors who specialise in the diagnosis and treatment of hormonal imbalances. To diagnose the disorders, doctors order blood and urine tests. These are used to measure the levels of hormones in the patient’s blood. If abnormalities are detected, doctors order imaging tests. These can confirm or rule out the presence of a tumour in the pituitary gland. Commonly used imaging tests are computed tomography (CT) scan and magnetic resonance imaging (MRI).
Treatment of the disorders focuses on normalising the levels of hormones in the body. This can be achieved with the use of synthetic hormones that patients may need to take for the rest of their lives. Medications that decrease the production of certain hormones may also be used.
Many patients with these disorders have tumours in their pituitary gland. Such abnormal growths can be removed through surgery. This can be done through the sphenoid sinus. This is a hollow space located below the brain and behind the nasal passages. It requires making a small incision along the nasal septum and opening the boney walls of the sphenoid sinus to access the tumour. The procedure can also be performed using an endoscope. This is a minimally invasive approach in which a fibre-optic tube with a tiny camera is inserted through the nasal passages. Thus, it does not require incisions. This approach is for patients who have small pituitary gland tumours.
Patients with larger or more complicated pituitary gland tumours may require a craniotomy. This approach involves making a surgical opening into the skull. Because this approach creates a wider opening, it provides surgeons a better view of the surgical site. This can help reduce the risk of damage to surrounding structures.
The best surgical method to use depends on the size of the tumour, the patient’s general health condition, and the severity of symptoms. Surgery is only considered if medications fail to work.
Mancall, Elliott L.; Brock, David G., eds. (2011). “Cranial Fossae”. Gray’s Clinical Anatomy. Elsevier Health Sciences. p. 154.
Pituitary tumors information page. National Institute of Neurological Disorders and Stroke. http://www.ninds.nih.gov/disorders/pituitary_tumors/pituitary_tumors.htm.
Martinkova J, et al. Impulse control disorders associated with dopaminergic medication in patients with pituitary adenomas. Clinical Neuropharmacology. 2011;34:179.