Pituitary tumor
Tumor - pituitary; Pituitary adenoma
A pituitary tumor is an abnormal growth in the pituitary gland. The pituitary is a small gland at the base of the brain. It regulates the body's balance of many hormones.
Causes
Most pituitary tumors are noncancerous ( benign ). Up to 20% of people have pituitary tumors. Many of these tumors do not cause symptoms and are never diagnosed during the person's lifetime.
Benign
"Benign" refers to a condition, tumor, or growth that is not cancerous. This means that it does not spread to other parts of the body. It does not ...
The pituitary gland is a pea-sized endocrine gland located at the base of the brain. The pituitary helps control the release of hormones from other endocrine glands, such as the thyroid, sex glands (testes or ovaries), and adrenal glands . The pituitary also releases hormones that directly affect body tissues, such as bones and the breast milk glands. The pituitary hormones include:
Endocrine
Endocrine glands release (secrete) hormones into the bloodstream. The endocrine glands include:AdrenalHypothalamusIslets of Langerhans in the pancrea...
Adrenal glands
The adrenal glands are two triangle-shaped glands. One gland is located on top of each kidney.
- Adrenocorticotropic hormone (ACTH)
- Growth hormone (GH)
- Prolactin
- Thyroid-stimulating hormone (TSH)
- Luteinizing hormone (LH) and follicle-stimulating hormone (FSH)
As a pituitary tumor grows, the normal hormone-releasing cells of the pituitary may be damaged. This results in the pituitary gland not producing enough of its hormones. This condition is called hypopituitarism .
Hypopituitarism
Hypopituitarism is a condition in which the pituitary gland does not produce normal amounts of some or all of its hormones.
The causes of pituitary tumors are unknown. Some tumors are part of a hereditary disorder called multiple endocrine neoplasia I (MEN I).
Multiple endocrine neoplasia I
Multiple endocrine neoplasia (MEN) type I is a disease in which one or more of the endocrine glands are overactive or forms a tumor. It is passed do...
The pituitary gland can be affected by brain tumors that develop in the same part of the brain, resulting in similar symptoms.
Symptoms
Some pituitary tumors produce too much of one or more hormones. As a result, symptoms of 1 or more of the following conditions can occur:
-
Hyperthyroidism
(thyroid gland makes too much of its hormones; this is an extremely rare condition of pituitary tumors)
Hyperthyroidism
Hyperthyroidism is a condition in which the thyroid gland makes too much thyroid hormone. The condition is often called overactive thyroid.
-
Cushing syndrome
(body has a higher than normal level of the hormone cortisol)
Cushing syndrome
Cushing syndrome is a disorder that occurs when your body has a high level of the hormone cortisol.
-
Gigantism
(abnormal growth due to higher than normal level of growth hormone during childhood) or
acromegaly
(higher than normal level of growth hormone in adults)
Gigantism
Gigantism is abnormal growth due to an excess of growth hormone during childhood.
Acromegaly
Acromegaly is a condition in which there is too much growth hormone in the body.
-
Nipple discharge
and irregular or absent menstrual periods in women
Nipple discharge
Nipple discharge is any fluid that comes out of the nipple area in your breast.
- Decreased sexual function in men
Symptoms caused by pressure from a larger pituitary tumor may include:
- Changes in vision such as double vision, visual field loss, drooping eyelids or changes in color vision
- Headache
- Lack of energy
- Nasal drainage of clear fluid
- Nausea and vomiting
- Problems with the sense of smell
-
In rare cases, these symptoms occur suddenly and can be severe (
pituitary apoplexy
).
Pituitary apoplexy
Pituitary apoplexy is a rare, but serious condition of the pituitary gland.
Exams and Tests
Your health care provider will perform a physical examination. The provider will note any problems with double vision and visual field, such as a loss of side (peripheral) vision or the ability to see in certain areas.
The exam will check for signs of too much cortisol (Cushing syndrome) or too much growth hormone (acromegaly).
Tests to check endocrine function may be ordered, including:
-
Cortisol levels:
dexamethasone suppression test
,
urine cortisol
test
Dexamethasone suppression test
Dexamethasone suppression test measures whether adrenocorticotrophic hormone (ACTH) secretion by the pituitary can be suppressed.
Urine cortisol
The cortisol urine test measures the level of cortisol in the urine. Cortisol is a steroid (glucocorticoid) hormone produced by the adrenal gland. C...
-
FSH
level
FSH
The follicle stimulating hormone (FSH) blood test measures the level of FSH in blood. FSH is a hormone released by the pituitary gland, located on t...
- Insulin growth factor-1 (IGF-1) level
-
LH
level
LH
The LH blood test measures the amount of luteinizing hormone (LH) in blood. LH is a hormone released by the pituitary gland, located on the undersid...
-
Prolactin level
Prolactin level
Prolactin is a hormone released by the pituitary gland. The prolactin test measures the amount of prolactin in the blood.
- Testosterone/estradiol levels
-
Thyroid hormone levels:
free T4 test
,
TSH test
Free T4 test
T4 (thyroxine) is the main hormone produced by the thyroid gland. A laboratory test can be done to measure the amount of free T4 in your blood....
TSH test
A TSH test measures the amount of thyroid stimulating hormone (TSH) in your blood. TSH is produced by the pituitary gland. It tells the thyroid gla...
Tests that help confirm the diagnosis include the following:
- Visual fields
- MRI of head
Treatment
Surgery to remove the tumor is often needed, especially if the tumor is pressing on the optic nerves (nerves that control vision).
Most of the time, pituitary tumors can be surgically removed through the nose and sinuses. If the tumor cannot be removed this way, it is removed through the skull.
Radiation therapy may be used to shrink the tumor in people who cannot have surgery. It may also be used if the tumor returns after surgery.
Radiation therapy
Radiation therapy uses high-powered x-rays, particles, or radioactive seeds to kill cancer cells.
In some cases, medicines are prescribed to shrink certain types of tumors.
Support Groups
Pituitary Network Association: www.pituitary.org
Outlook (Prognosis)
If the tumor can be surgically removed, the outlook is fair to good, depending on whether the entire tumor is removed.
Possible Complications
The most serious complication is blindness. This can occur if the optic nerve is seriously damaged.
The tumor or its removal may cause lifelong hormone imbalances. The affected hormones may need to be replaced, and you may need to take medicine for the rest of your life.
Surgery can sometimes damage the posterior pituitary (back part of the gland). This can lead to diabetes insipidus , a condition with symptoms of frequent urination and extreme thirst.
Diabetes insipidus
Diabetes insipidus is an uncommon condition in which the kidneys are unable to prevent the excretion of water.
When to Contact a Medical Professional
Call your provider if you develop any symptoms of a pituitary tumor.
References
Melmed S, Kleinberg D. Pituitary masses and tumors. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, eds. Williams Textbook of Endocrinology . 13th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 9.
Muh CR, Oyesiku NM. Pituitary tumors. In: Ellenbogen RG, Abdulrauf SI, Sekhar LN, eds. Principles of Neurological Surgery . 3rd ed. Philadelphia, PA: Elsevier Saunders; 2012:chap 40.
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Endocrine glands - illustration
Endocrine glands release hormones (chemical messengers) into the bloodstream to be transported to various organs and tissues throughout the body. For instance, the pancreas secretes insulin, which allows the body to regulate levels of sugar in the blood. The thyroid gets instructions from the pituitary to secrete hormones which determine the pace of chemical activity in the body (the more hormone in the bloodstream, the faster the chemical activity; the less hormone, the slower the activity).
Endocrine glands
illustration
-
Endocrine glands - illustration
Endocrine glands release hormones (chemical messengers) into the bloodstream to be transported to various organs and tissues throughout the body. For instance, the pancreas secretes insulin, which allows the body to regulate levels of sugar in the blood. The thyroid gets instructions from the pituitary to secrete hormones which determine the pace of chemical activity in the body (the more hormone in the bloodstream, the faster the chemical activity; the less hormone, the slower the activity).
Endocrine glands
illustration
Review Date: 10/28/2015
Reviewed By: Brent Wisse, MD, Associate Professor of Medicine, Division of Metabolism, Endocrinology & Nutrition, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.