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Pituitary tumor

Show Alternative Names
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 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.

The 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:

  • Adrenocorticotropic hormone (ACTH)
  • Growth hormone (GH)
  • Prolactin
  • Thyroid-stimulating hormone (TSH)
  • Luteinizing hormone (LH) and follicle-stimulating hormone (FSH)

Video Transcript

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.

The causes of pituitary tumors are unknown. Some tumors are caused by hereditary disorders such as multiple endocrine neoplasia I (MEN I).

The 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)
  • Cushing syndrome (body has a higher than normal 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)
  • Nipple discharge and irregular or absent menstrual periods in women
  • 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 (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).

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), too much growth hormone (acromegaly), or too much prolactin (prolactinoma).

Tests to check endocrine function may be ordered, including:

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 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.

In 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:

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.

When to Contact a Medical Professional

Contact your provider if you develop any symptoms of a pituitary tumor.

Text only

Review Date: 5/13/2021

Reviewed By

Brent Wisse, MD, Board Certified in Metabolism/Endocrinology, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

References

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.

Disclaimer

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- A.D.A.M., a business unit of Ebix, Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

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Endocrine glands - Illustration Thumbnail

Endocrine glands

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 rate of metabolism in the body (the more hormone in the bloodstream, the faster the chemical activity; the less hormone, the slower the activity).

Illustration

The pituitary gland - Illustration Thumbnail

The pituitary gland

The pituitary is a gland attached to the base of the brain. The pituitary secretes hormones that regulate the body's balance of many hormones controlling growth, development, and metabolism of the body.

Illustration

Endocrine glands - Illustration Thumbnail

Endocrine glands

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 rate of metabolism in the body (the more hormone in the bloodstream, the faster the chemical activity; the less hormone, the slower the activity).

Illustration

The pituitary gland - Illustration Thumbnail

The pituitary gland

The pituitary is a gland attached to the base of the brain. The pituitary secretes hormones that regulate the body's balance of many hormones controlling growth, development, and metabolism of the body.

Illustration

 
 
 
 

 

 
 

 
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