Our thanks to Daniel Kelly, M.D. (Director, Neuro-Endocrine Tumor Center - John Wayne Cancer Institute at Saint's John Health Center, Santa Monica, CA) and Pejman Cohan, M.D. (Director, Specialized Endocrine Care Center - Beverly Hills, CA) for providing the following disorder information.
Introduction To The Pituitary Gland
The pituitary is a small, bean-shaped gland located below the brain in the skull base, in an area called the pituitary fossa or sella turcica. The gland is regulated by a region of the brain called the hypothalamus and they are connected by a thin delicate vascular connection called the pituitary stalk or infundibulum. Weighing less than one gram and measuring a centimeter in width, the pituitary gland is often called the "master gland" since it controls the secretion of the body's hormones. These substances when released by the pituitary into the blood stream have a dramatic and broad range of effects on growth and development, sexuality and reproductive function, metabolism, the response to stress and overall quality of life. The pituitary gland is thus at the anatomical and functional crossroads of the brain, mind and body.
Structurally, the pituitary gland is divided into a larger anterior region (adenohypophysis) and a smaller posterior region (neurohypophysis). Directly above the pituitary gland are the crossing fibers of the optic nerves called the optic chiasm as well as the optic nerves as they project to the eyes. On each side of the pituitary gland is the cavernous sinus which is a venous channel through which runs the large carotid arteries that carry blood to the brain, and important nerves that control eye movements and facial sensation. Because of the close proximity of the pituitary gland to these major intracranial nerves and blood vessels, as well as the vital hormonal control the pituitary gland provides, disorders of the pituitary can cause a wide spectrum of symptoms, both hormonal and neurological.
Listed below are the specific hormones produced by the pituitary:
Growth Hormone (GH): This is the principal hormone that, among many other functions, regulates body and brain development, bone maturation, metabolism and is essential for healthy muscles.
Luteinizing Hormone (LH) and Follicle Stimulating Hormone (FSH): These hormones control the production of sex hormones (estrogen and testosterone) as well as sperm and egg maturation and release.
Prolactin (PRL): This hormone stimulates secretion of breast milk.
Thyroid Stimulating Hormone (TSH): This hormone stimulates the thyroid gland to release thyroid hormones. Thyroid hormones control basal metabolic rate and play an important role in growth and maturation. Thyroid hormones affect almost every organ in the body.
Adrenocorticotropic Hormone (ACTH): This hormone triggers the adrenal glands (located above the kidneys) to release the hormone cortisol which in turn, regulates carbohydrate, fat, and protein metabolism and is essential in the stress response.
Vasopressin - Also called anti-diuretic hormone (ADH): This hormone promotes water to be reabsorbed by the kidneys and is thus essential in water and electrolyte balance.
In disease states, the pituitary gland may under- or over-produce hormones. Decreased or absent hormone production from the pituitary gland is called hypopituitarism (Pituitary Failure). The symptoms and treatments for pituitary failure are listed below:
Children: Growth delay
|Recombinant Human Growth Hormone - Given once daily as an injection under the skin.|
Decreased libido, erectile dysfunction, irregular or absent menses, decreased body hair, decreased muscle strength, hot flashes, mood changes
Men: Testosterone - Given once daily as an injection under the skin
Poor appetite, nausea, weakness, vomiting, low blood sugar, low blood pressure, dizziness, body aches
|Hydrocortisone or Prednisone - Given as daily pills|
Fatigue, weakness, cold intolerance, dry skin, constipation, heavy and/or painful menses, weight gain, memory loss, mood disturbance
|Levothyroxine - Given as daily pills (some examples include Synthroid or Levoxyl or Levothroid or Armour Thyroid|
Increased thirst and frequent urination
|DDAVP - Given either as daily pills or nasal spray|
Pituitary tumors (also called pituitary adenomas) can result in hormonal overproduction causing serious endocrine disturbances such as acromegaly (excess GH), Cushing's disease (excess ACTH) or prolactinoma (excess prolactin). Other pituitary adenomas are non-functional or "endocrine-inactive," meaning that they do not produce excess hormones. Instead, as these tumors enlarge, they can cause compression of the normal pituitary gland leading to decreased or absent hormone production (hypopituitarism or pituitary failure), visual loss from optic chiasm or optic nerve compression and headaches. Pituitary failure may also result from bleeding into a pituitary tumor, pituitary or intracranial surgery, radiation therapy to the pituitary or head trauma. Other tumors that arise near the pituitary gland which can also impact pituitary hormonal function include Rathke's cleft cysts, craniopharyngiomas, meningiomas, chordomas, gliomas and epidermoid cysts.
From Our Founder:
If you are just learning about pituitary tumors and the many associated problems and hormonal disorders let us start with a frank discussion of where you are: Pituitary Tumors, though described in some textbooks as "benign" can be very aggressive and can do irreparable harm. Some can even be lethal IF NOT PROPERLY TREATED!
Do not allow your physicians, or yourself or family to treat these tumors lightly or in a start and stop fashion. Get highly qualified professional help. As with cancer or heart disease, you need expert help, only. The last seventy years have been remarkable in pituitary endocrinology. In the 1930's for instance, Cushings Disease was a death sentence; patients lived an average of 4.7 years after presentation of illness. In the 1950's, the five year survival rate was 50%. The cure rate for microadenomas today is approximately 90% and improving. Experts in Neurosurgery and Pituitary Endocrinology have so improved the cure rate in a mere 70 plus years that the general medical community, and certainly insurance companies and others, tend to think of Pituitary Disease the way they think of Polio. The threat is over and the scourge has left us. Sadly, with Pituitary Tumors this is not the case. Each and every patient has to be evaluated and "fought for" or the battle may be lost.
These tumors act and grow differently in every patient. A correct diagnosis and treatment plan is essential for the survival of many of us. Yes, clearly, in many they are slow growing and may cause little apparent outward damage. Regretably, many with so called "incidental" or "non-secreting" tumors often have symptoms which their physicians simply forget or are untrained to ask about. Sexual function, mental health, overall ability to function and fit in, are all vital aspects of our lives. The tumor may not "take" our life but may in fact change it to the point of lowering the patient’s quality of life. Study, learn, seek expert help and join the PNA as we continue to bring you the REAL facts about these insidious diseases and their consequences.
Through research pituitary medicine is improving every day. We are here to inform and alert you about Pituitary and Hormonal disorders. If we help make your life better, we have succeeded. Good luck and God Bless.