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by McCoy K
(Pituitary Tumor; Nervous System Tumor)

Definition

A pituitary adenoma is a growth, or tumor, in the pituitary gland. The pituitary is a small gland at the base of the brain. It makes hormones that affect growth and the action of other glands in the body.

Pituitary adenomas are usually not cancer and will not spread to other parts of the body. However, they can lead to vision and growth problems. A pituitary adenoma can also change the balance of hormones of the thyroid, adrenal, and gonad glands.

Pituitary Gland
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Causes

DNA changes cause the growth of a tumor. It is not always clear what causes these changes.

Some tumors are part of other endocrine disorders. These disorder may be caused by genes that are passed down in families. Tumors may also be caused by exposure to cancer-causing substances or radiation.

Risk Factors

The chance of pituitary adenoma may be higher with:

  • Family or personal history of multiple endocrine neoplasia, type 1 (MEN1)
  • Other inherited disorders such as Carney complex, acromegaly, or gigantism

Symptoms

Symptoms can vary. They will depend on the size of the tumor and if the tumor is sending out hormones. The tumor can also cause problem because it is at the base of the brain. Some may not have any symptoms.

Symptoms due to size may include:

  • Headache
  • Blurred vision or tunnel vision

A prolactin-secreting adenoma may cause:

  • Milk production in nonlactating women
  • Loss of or irregular periods
  • Lack of interest in sex
  • Vaginal dryness

A thyrotropin-secreting adenoma may cause swelling of the neck.

If the adenoma causes hyperthyroidism it may lead to:

  • Tremors
  • Rapid heartbeat
  • Anxiety
  • Weight loss
  • Insomnia

A corticotropin-secreting adenoma may cause:

  • Menstrual disturbance
  • Skin changes such as increased facial hair in women, acne, bruising, or bluish stretch marks
  • Buffalo hump, an increase in fatty tissue on the back
  • Obesity, especially around the wrist
  • Round face

A growth hormone-secreting adenoma may cause:

  • Enlarged hands and feet
  • Excessive growth and height
  • Oily skin
  • Excess sweating

Pituitary adenomas may also play a role in:

Diagnosis

The doctor will ask about symptoms and past health. A physical exam will be done. A doctor who specializes in glands and hormones is an endocrinologist. Tests that may be done include:

  • Blood and urine tests to check hormone levels
  • Vision tests
  • Images of brain which may be done with an MRI

Treatment

Treatment will depend on the size and impact of the tumor. Tumor that are not causing problems may not need immediate treatment. The doctor will schedule regular exams to track any changes.

Treatment may focus on managing hormone changes caused by the tumor or tumor removal. Several treatment may be used in combination. Treatment choices may include:

Surgery

Tumors that are pressing on nearby structures may need to be removed. Many may be removed through the nose. Healthy pituitary gland tissue may also be removed during surgery. Hormone medicine may be needed after surgery.

Medicine

Medicine can control symptoms and sometimes shrink the tumor. They can also block hormones from the tumor.

Medicine may be useful for prolactin or growth hormone-secreting adenomas.

Radiation Therapy

Radiation therapy can kill tumor cells. The types of radiation therapy used to treat pituitary adenomas include:

  • Conventional therapy—radiation is directed at the pituitary from a source outside the body
  • Stereotactic radiosurgery—an intense radiation beam is targeted directly at the tumor
  • Proton beam radiotherapy—a beam of protons is focused on the tumor

Prevention

The cause of pituitary adenoma is not clear so there are no prevention steps.

RESOURCES

American Cancer Society  http://www.cancer.org 

Hormone Health Network—Endocrine Society  http://www.hormone.org 

CANADIAN RESOURCES

Canadian Cancer Society  http://www.cancer.ca 

Brain Tumor Foundation of Canada  http://www.braintumour.ca 

References

Becker A, Daly AF. The clinical, pathological, and genetic features of familial isolated pituitary adenomas. Eur J Endocrinol 2007;57(4):371-82.

Beshay VE, Beshay JE, Halvorson LM. Pituitary tumors: diagnosis, management, and implications for reproduction. Semin Reprod Med 2007;25(5):388-401.

General information about pituitary tumors. National Cancer Institute website. Available at: http://www.cancer.gov/types/pituitary/patient/pituitary-treatment-pdq. Accessed September 24, 2020.

NINDS pituitary tumors information page. National Institute of Neurological Disorders and Stroke website. Available at: http://www.ninds.nih.gov/disorders/pituitary%5Ftumors/pituitary%5Ftumors.htm. Accessed September 24, 2020.

Pituitary tumors. American Cancer Society website. Available at: http://www.cancer.org/acs/groups/cid/documents/webcontent/003133-pdf.pdf. Accessed September 24, 2020.

Pituitary tumors. EBSCO DynaMed website. Available at:  http://www.dynamed.com/topics/dmp~AN~T900666/Pituitary-tumors  . Accessed September 24, 2020.

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