Pituitary tumor
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 10% 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 in...
Read Article Now Book Mark ArticleThe pituitary is part of the endocrine system. 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...
Read Article Now Book Mark ArticleAdrenal glands
The adrenal glands are two small triangle-shaped glands in the upper abdomen. One gland is located on top of each kidney.
Read Article Now Book Mark Article- Adrenocorticotropic hormone (ACTH)
- Growth hormone (GH)
- Prolactin
- Thyroid-stimulating hormone (TSH)
- Luteinizing hormone (LH) and follicle-stimulating hormone (FSH)
Pituitary gland - Animation
The pituitary gland is often referred to as the master gland of the body, since it regulates many activities of other endocrine glands. Located above the pituitary gland is the hypothalamus. The hypothalamus decides which hormones the pituitary should release by sending it either hormonal or electrical messages. In response to hormonal messages from the hypothalamus, the pituitary gland releases the following hormones. GH (growth hormone) - increases size of muscle and bone. THS (thyroid stimulating hormone) - stimulates the thyroid gland to release T3 and T4 to stimulate metabolism in other cells throughout the body. FSH (follicle stimulating hormone) - stimulates ovarian follicle production in women; stimulates sperm production in men. LH (luteinizing hormone) - stimulates ovaries to produce estrogen in women; stimulates sperm production in men. Prolactin - stimulates breast tissue in nursing mothers to produce milk. ACTH (adrenocorticotropic hormone) - causes the adrenal glands to produce important substances that have properties similar to steroids. In response to electrical messages from the hypothalamus, the pituitary gland releases the following hormones. ADH (antidiuretic hormone) - stimulates the kidneys to reabsorb fluid and produce less urine; Oxytocin - initiates labor, uterine contractions, and milk ejection in mothers.
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.
Read Article Now Book Mark ArticleThe causes of pituitary tumors are unknown. Some tumors are caused by hereditary disorders such as 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...
Read Article Now Book Mark ArticleThe pituitary gland can be affected by other brain tumors that develop in the same part of the brain (skull base), resulting in similar symptoms.
Symptoms
Some pituitary tumors produce too much of one or more hormones. As a result, symptoms of one 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.
Read Article Now Book Mark Article - 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.
Read Article Now Book Mark Article - 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 (GH) during childhood.
Read Article Now Book Mark ArticleAcromegaly
Acromegaly is a condition in which there is too much growth hormone (GH) in your body.
Read Article Now Book Mark Article - Nipple discharge and irregular or absent menstrual periods in women due to excess of the hormone prolactin
Nipple discharge
Nipple discharge is any fluid that comes out of the nipple area in your breast.
Read Article Now Book Mark Article - Decreased sexual function in men due to excess of the hormone prolactin
Symptoms caused by pressure from a larger pituitary tumor may include:
- Changes in vision such as double vision, visual field loss (loss of peripheral vision), drooping eyelids or changes in color vision.
- Headache.
- Lack of energy.
- Nasal drainage of clear, salty 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.
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Exams and Tests
Your health care provider will perform a physical examination. Your 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), too much growth hormone (acromegaly), or too much prolactin (prolactinoma).
Prolactinoma
A prolactinoma is a noncancerous (benign) pituitary tumor that produces a hormone called prolactin. This results in too much prolactin in the blood....
Read Article Now Book Mark ArticleTests to check endocrine function may be ordered, including:
- Cortisol levels -- dexamethasone suppression test, urine cortisol test, salivary cortisol test
Dexamethasone suppression test
The dexamethasone suppression test measures whether cortisol secretion by the adrenal gland can be suppressed. It can also help assess the reason fo...
Read Article Now Book Mark ArticleUrine cortisol
The cortisol urine test measures the level of cortisol in the urine. Cortisol is a glucocorticoid (steroid) hormone produced by the adrenal gland. C...
Read Article Now Book Mark Article - 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...
Read Article Now Book Mark Article - 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...
Read Article Now Book Mark Article - Prolactin level
Prolactin level
Prolactin is a hormone released by the pituitary gland. The prolactin test measures the amount of prolactin in the blood.
Read Article Now Book Mark Article - 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. Fre...
Read Article Now Book Mark ArticleTSH test
A TSH test measures the amount of thyroid stimulating hormone (TSH) in your blood. TSH is produced by the pituitary gland. It prompts the thyroid g...
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Tests that help confirm the diagnosis include the following:
- Visual fields
Visual fields
The visual field refers to the total area in which objects can be seen in the side (peripheral) vision as you focus your eyes on a central point. Thi...
Read Article Now Book Mark Article - MRI of head
MRI of head
A head MRI (magnetic resonance imaging) is an imaging test that uses powerful magnets and radio waves to create pictures of the brain and surrounding...
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Treatment
Surgery to remove the tumor is often needed, especially if the tumor is pressing on the nerves that control vision (optic nerves).
Most of the time, pituitary tumors can be surgically removed through the nose and sinuses (transsphenoidal). 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 radiation (such as x-rays or gamma rays), particles, or radioactive seeds to kill cancer cells.
Read Article Now Book Mark ArticleIn some cases, medicines are prescribed to shrink certain types of tumors.
Small tumors found incidentally during an MRI for other symptoms can often be followed with repeat MRI imaging over time if they are not causing any hormonal abnormality. Many of these tumors do not grow.
Support Groups
More information and support for people with pituitary tumors and their families can be found at:
- National Cancer Institute -- www.cancer.gov/types/pituitary
- Pituitary Network Association -- 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.
Tumors and 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 (DI) is an uncommon condition in which the kidneys are unable to prevent the excretion of water. DI is not the same as diabetes me...
Read Article Now Book Mark ArticleWhen to Contact a Medical Professional
Contact your provider if you develop any symptoms of a pituitary tumor.
Reviewed By
Sandeep K. Dhaliwal, MD, board-certified in Diabetes, Endocrinology, and Metabolism, Springfield, VA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
Dorsey JF, Salinas RD, Dang M, et al. Cancer of the central nervous system. In: Niederhuber JE, Armitage JO, Kastan MB, Doroshow JH, Tepper JE, eds. Abeloff's Clinical Oncology. 6th ed. Philadelphia, PA: Elsevier; 2020:chap 63.
Melmed S. Pituitary masses and tumors. In: Melmed S, Auchus RJ, Goldfine AB, Koenig RJ, Rosen CJ, eds. Williams Textbook of Endocrinology. 14th ed. Philadelphia, PA: Elsevier; 2020:chap 9.