PITUITARY DISORDERS

PITUITARY PROBLEMS


Pituitary gland is a small gland in our brain. It is known as master gland as it controls all other endocrine glands. It produces various hormones which interact with other endocrine glands. Certain conditions could affect this gland such as post brain surgery, radiation therapy, head injury, absent gland development from birth etc. They can manifest in several ways such as short stature, delayed puberty, thyroid problems and lack of energy.



PITUITARY TUMORS


The most frequent type of pituitary disorder is a pituitary glandtumor. These tumors are fairly common in adults. They are not brain tumors and are almost always benign (that is, not cancer). In fact, cancerous tumors of this sort are extremely rare.


There are two types of tumors-secretory and non-secretory. Secretory tumors produce too much of a hormone normally made by the pituitary, and non-secretory tumors do not. Both types of tumors can cause problems if they are large and interfere with normal function of the pituitary gland and/or nearby structures in the brain.


The problems caused by pituitary tumors fall into three general categories:


  • Hypersecretion: Too much of any hormone in the body is caused by a secretory pituitary tumor.
  • Hyposecretion: Too little of any hormone in the body can be caused by a large pituitary tumor, which interferes with the pituitary glands ability to produce hormones. Hyposecretion can also result from surgery or radiation of a tumor.


Tumor mass effects: As a pituitary tumor grows and presses against the pituitary gland or other areas in the brain, it may cause headaches, vision problems, or other health effects.


Injuries, certain medications, bleeding inside or close to the pituitary, and other conditions can also affect the pituitary gland. Loss of normal pituitary function also can occur after major head trauma.



TREATMENT OPTIONS


Medications :


Several types of drugs can help relieve pituitary problems. Prolactinomas, for example, respond well to a dopamine agonist drug. If surgery does not remove the entire pituitary gland tumor, somatostatin analogues are used in patients with acromegaly, TSH-secreting tumors, and some cases of Cushings disease. Medication is used to lower high hormone levels or to shrink the tumor. Sometimes pegvisomant may be used to block the action of growth hormone. In many cases, drug therapy is combined with surgery and/or radiation treatment, or more than one drug can be used at the same time for combined effects. Hormone Therapy for Hyposecretion


Sometimes tumors cause a lack of a hormone. Other times, the lack of a hormone is caused by the treatment you have for pituitary tumors. Surgery or radiation therapy, for example, can lead to permanent loss of hormone secretion. In these cases, hormone replacement therapy is an important part of treatment.


Some types of hormones are necessary for survival. These hormones must be replaced immediately. They include TSH, or thyroid stimulating hormone-regulates thyroid hormone production, which, in turn, regulates metabolism. If a problem with TSH secretion is causing low thyroid hormone levels, you may also need to start thyroid hormone replacement. Antidiruetic hormone (ADH), or vasopressin-controls the body's water balance.


Other hormones, such as estrogen and progesterone in women, and testosterone in men, also may need to be replaced. While they are not vital for survival, they may help you to live a full and healthy life. In addition to reproductive effects, these hormones are important for many functions such as maintaining normal bone and muscle mass.


Estrogen and progesterone hormone replacement in young women is not the same as post-menopausal hormone therapy. In the latter case, hormones are being given at a time in life when they are not normally made. For more information about the pros and cons to estrogen and progesterone replacement during menopause, see the Hormone Health Network section on menopause.


Some hormones may return to normal levels after treatment for a pituitary condition. In other cases, there may be some permanent loss of hormone function. You may need to continue with some type of hormone therapy for many years or the rest of your life. Your doctor will work with you to monitor and adjust your hormone replacement therapy as needed.


Surgery :


The most common form of surgery to remove pituitary tumors is transsphenoidal microsurgery. A neurosurgeon approaches the pituitary gland tumor through the nose, in the sphenoid sinus cavity. Using this natural pathway, the surgeon does not need to operate on your skull. With a surgical microscope and special instruments, the surgical goal is to safely remove the tumor without damaging the surrounding pituitary gland.


Radiation therapy :


To treat a pituitary gland tumor with radiation, doctors may use a variety of techniques depending on the size and location of the tumor. Conventional radiation covers a wide area in and around the tumor and is usually given daily for several weeks. A number of more focused "radiosurgery" therapies, such as gamma knife and proton beam, may be appropriate.


All radiation therapy works slowly and it may take from six months at a minimum to many years for your condition to improve. This is why radiation therapy is usually used together with other medical therapies to normalize hormone secretion and/or control tumor size.



PITUITARY DISORDERS



Pituitary gland is a pea-sized gland situated at the skull base in a small bony cup which is just behind the bridge of our nose. It is considered as the "Master endocrine gland" as it controls the function of endocrine glands. It therefore plays a very important role in regulating vital body functions and general well being.




Pituitary gland secretes the following hormones,


  • Adrenocorticotropic hormone which stimulates the adrenal glands to secrete steroid hormones such as cortisol
  • Growth hormone which regulates growth, metabolism and body composition
  • Luteinising hormone and follicle stimulating hormone, also known as gonadotrophins. They act on the ovaries or testes to stimulate sex hormone production and egg and sperm maturity.
  • Prolactin which stimulates milk production
  • Thyroid stimulating hormone which stimulates the thyroid gland to secrete thyroid hormones.


There are also some hormones which are produced by the brain and then stored in the posterior pituitary gland prior to being released into the bloodstream.These are:


  • Anti-diuretic hormone which controls water balance and blood pressure
  • Oxytocin which stimulates uterine contractions during labour and milk secretion during breastfeeding.


Several conditions could affect the pituitary gland directly. These are either,


  • Conditions that cause the pituitary gland to produce too much of one or more hormone(s).Examples include acromegaly, Cushing's disease and prolactinoma.
  • Conditions that cause the pituitary gland to produce too little of one or more hormone(s).Examples include adult growth hormone deficiency, diabetes insipidus or hypopituitarism.
  • Conditions that alter the size and/or shape of the pituitary gland.Examples include pituitary adenoma.