The pituitary gland is located near the brain.
The master endocrine gland because it releases hormones that affect many bodily functions.
It is controlled by the hypothalamus, that is connected to the pituitary gland.
A pituitary gland has 2 lobes, the anterior, pand the posterior.
Anterior pituitary lobe hormones:
Thyroid stimulating hormone (TSH) stimulates the thyroid gland, which helps regulate the body’s metabolism.
Adrenocorticotrophic hormone (ACTH) controls the hormones released by the adrenal gland, which supports blood pressure, metabolism, and the body’s response to stress.
Gonadotropins, a family of hormones that include follicle stimulating hormone (FSH) and luteinizing hormone (LH), stimulate production of sperm or eggs, and also regulate the menstrual cycle.
Growth hormone promotes growth of the long bones in the arms and legs, and thickens the skull and bones of the spine.
Growth hormone also causes the tissue over the bones to thicken.
Prolactin stimulates milk production in women after childbirth. Prolactin is also found in men.
Lipotropin stimulates the movement of fat from the body to the bloodstream.
Melanocyte stimulating hormone (MSH) regulates the production of melanin, the pigment in skin.
Posterior pituitary lobe hormones
Oxytocin stimulates contraction of the uterus during childbirth and the flow of milk during breastfeeding.
Antidiuretic hormone, also known as vasopressin, increases reabsorption of water by the kidneys and allows a person to stay hydrated.
Tumors in the pituitary gland can be cancerous or benign.
Most pituitary gland tumors are noncancerous growths called pituitary adenomas.
A benign pituitary gland tumor can act like a cancerous tumor by growing into nearby tissue and structures, or rarely, spreading to other parts of the body.
The pituitary gland is located under the brain and is separate from the brain.
Pituitary tumors are classified as endocrine tumors.
Pituitary tumors can lead to hormone deficiencies or excesses.
If the tumor presses on nearby structures, such as the optic nerves, it can impair vision.
Approximately 14,230 pituitary tumors will be diagnosed in the United States in 2017.
No evidence exists that environmental factors play a role in the development of a pituitary gland tumors.
There are 3 hereditary syndromes associated with pituitary tumors: Multiple endocrine neoplasia type 1 (MEN1), Carney complex, and Familial acromegaly.
Patients may present with:
Headaches
Vision problems
Changes in menstrual cycles in women
Impotence
Infertility
Inappropriate production of breast milk
Cushing’s syndrome
Acromegaly
Unexplained tiredness
Mood changes
Irritability
A pituitary tumor causes symptoms in 3 different ways: By producing too much of 1 or more hormones, causing it to make too little of 1 or more hormones, and pressing on the optic nerves or, less commonly, the nerves controlling eye movements, and causing either loss of part or all of a person’s sight, or double vision.
Growth hormone excess: The symptoms depend on a patient’s age. In children, before the bone plates have closed, increased growth can cause gigantism, which is excessive body size and height. In adults, increased growth hormone causes acromegaly, a syndrome that includes excessive growth of soft tissues and bones, high blood sugar, high blood pressure, heart disease, sleep apnea, increased snoring, carpal tunnel syndrome, and pain, including headaches.
Thyroid stimulating hormone (TSH) in excess causes increased production of thyroid hormone, and can lead to hyperthyroidism.
Prolactin hormone stimulates lactation and the secretion of progesterone in excess causes inappropriate secretion of breast milk, even in men.
Prolactin in excess can also cause osteoporosis, loss of sex drive; infertility; irregular menstrual cycles; and impotence.
Adrenocorticotropic hormone excess causes weight gain, high blood pressure, high blood sugar, osteoporosis emotional changes, stretch marks, and easy bruising.
Gonadotropins (FSH and LH) excess rarely can cause infertility and irregular menstrual cycles in women.
Pressure on the pituitary gland, can cause a deficiency of hormone production.
Growth hormone deficiency causes late growth in children, poor muscle strength, irritability, weakening of bone strength, and an overall unwell feeling.
Low TSH causes fatigue, low energy, sensitivity to cold temperatures, constipation, and weight gain.
Too little prolactin causes inability to breastfeed after a woman gives birth to a baby.
Too little ACTH causes fatigue and low energy, low blood pressure, low blood sugar, and upset stomach.
Low levels of gonadotropins cause infertility, decrease in sex drive, impotence, and irregular menstrual cycles.
MRI is better than a computed tomography scan, to diagnose most pituitary gland tumors, and it is now the standard imaging technique.
CT scan is usually used for patients who have a pacemaker or an aneurysm clip, which may prevent them from having an MRI.
A pituitary gland tumor may press on the optic nerves, and cause a visual field problem.
A microadenoma is small, meaning its 10 millimeters or less.
A macroadenoma is larger than 10 mm at its widest point, and can extend outside the sella turcica, the bony structure around the pituitary gland.
Other factors considered when classifying a pituitary gland tumor include whether the tumor is functional, and whether it has grown into nearby structures.
The tumor most commonly grows into is the cavernous sinus contains the carotid artery and several important nerves that control eye movement.
Patients with a pituitary tumor should be seen by an endocrinologist, a neurosurgeon, and an ophthalmologist.
Treatment options and recommendations depend on:
The type and stage of tumor
Possible side effects
The patient’s preferences
The patient’s overall health
Survival rates depend on the type of tumor, the person’s age, and other factors.
The only known risk factors are the 3 hereditary syndromes.
Multiple endocrine neoplasia type 1 (MEN1).
Carney complex
Familial acromegaly.
Symptoms of pituitary tumors include;
Headaches
Vision problems
Changes in menstrual cycles in women
Impotence, which is the inability to achieve or maintain an erection in men.
Infertility,
Inappropriate production of breast milk
Cushing’s syndrome,
Acromegaly,
Unexplained tiredness
Mood changes
Irritability
Excess growth hormone related symptoms depend on a patient’s age.
In children, before the bone plates have closed, increased growth can cause gigantism, and in adults, increased growth hormone causes acromegaly.
Thyroid stimulating hormone excess causes increased production of thyroid hormone, and can lead to nervousness and irritability, fast heart rate and high blood pressure, heart disease, increased sweating, thin skin, and weight loss.
Too much prolactin, causes inappropriate secretion of breast milk, (even in men), can cause osteoporosis, loss of sex drive, infertility, irregular menstrual cycles; and impotence.
Adrenocorticotropic hormone in excess causes weight gain, particularly in the body’s trunk,high blood pressure, high blood sugar, brittle bones, emotional changes, stretch marks on the skin, and easy bruising.
Gonadotropins (FSH and LH) are usually not high enough to cause symptoms but can cause infertility and irregular menstrual cycles in women.
MRI can identify pituitary tumors and is better than a computed tomography scan to diagnose most pituitary gland tumors, and it is now the standard method.
Pituitary gland tumors are most commonly noncancerous and called a pituitary adenoma:
Pituitary adenomas are usually classified according to its size on an MRI.
A microadenoma is small, meaning its 10 millimeters [mm] or less.
A macroadenoma is larger than 10 mm at its widest point, and can extend outside the sella turcica, the bony structure around the pituitary gland.
Pituitary gland tumor classification include whether the tumor is functional, and whether it has grown into nearby structures.
The tumor most commonly grows into is the cavernous sinus, an area that contains the carotid artery and several important nerves that control eye movement.
Treatment options depend on several factors, including:
The type and stage of tumor
Possible side effects
The patient’s preferences
The patient’s overall health
Active surveillance is an option for some people with a pituitary gland tumor who have no symptoms from the tumor and normal hormone levels.
During active surveillance, the patient is monitored periodically examined for signs of tumor growth or progression.
Treatment would begin if the tumor patient manifested causing symptoms.
Surgery is the most common treatment for a pituitary gland tumor.
Surgery, is often successful in removing the entire tumor.
95% of surgeries to remove pituitary gland tumors are done by the transsphenoidal route, through the nasal passage
The rest are done through a craniotomy.
Both methods are equally safe and effective.
For some stereotactic radiation therapy is used when any part of the tumor is left after surgery.
Not all patients with part of a tumor remaining after surgery need radiation therapy.
Some noncancerous pituitary gland tumors do not grow back even when some of the tumor is left behind after surgery.
If the entire tumor is removed, then radiation therapy is not needed.
Radiation therapy can cause the pituitary gland to gradually lose the ability to make hormones after treatment ends, and hormone replacement therapy may be needed.
HRT is often necessary for patients with a pituitary tumor when the gland is not making enough of a hormone due to the disease.
Hormone replacement of the following may burped necessary
Thyroid hormones
Adrenal hormones
Growth hormone
Testosterone in men
Estrogen in women
If a pituitary tumor is overproducing a hormone, there are medications that can help.
Bromocriptine (Parlodel) and cabergoline (Dostinex) are used to treat tumors that secrete prolactin.
Octreotide (Sandostatin) or pegvisomant (Somavert) can be used to treat tumors that make growth hormone.
Octreotide can also be used to treat pituitary tumors that secrete thyroid-stimulating hormone.
Patients may be at risk for developing other types of cancer: with too much growth hormone have a higher risk of developing colon cancer or thyroid cancer, but only if the tumor was not completely removed during surgery and growth hormone levels are still high.
People with MEN1 syndrome or Carney complex need regular screening for the other tumors associated with that condition.
Radiation therapy can have late effects, in particular decreasing hormone production from the pituitary gland, which can take 5 to 7 years to develop.