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Definition

The pituitary is a small gland. It is at the base of the brain. The gland makes hormones that regulate growth and the activity of other glands. A pituitary adenoma is an abnormal growth, or tumor, in this gland. Pituitary adenomas are benign. This means they are not cancerous. They do not spread to other parts of the body. The growths can lead to vision and growth problems. It can also disrupt the hormonal balance.

Pituitary Gland

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Causes

The cause is unknown. Some tumors have been associated with changes in DNA. These can be inherited.

Tumors can also be a result of exposure to cancer causing substances. In some cases the DNA changes may occur for no known reason.

Risk Factors

Factors that increase your chance of pituitary adenoma include:

  • A family or personal history of multiple endocrine neoplasia, type 1 (MEN1) —a hereditary condition that increases the risk of developing pituitary, hypothalamus, and parathyroid tumors

Symptoms

Symptoms can vary quite a bit. It will depend on whether or not the tumor is secreting hormones. The tumor's location at the base of the brain can also cause symptoms.

General symptoms may include:

  • Headache
  • Blurred vision
  • Impotence and infertility
  • Painful intercourse

Symptoms from Prolactin Secreting Adenoma (40% of all cases)

  • Fractures from osteoporosis
  • Milk production from nonlactating females
  • Amenorrhea
  • Vaginal dryness

Symptoms from Thyrotropin-secreting Adenoma

  • Enlarged thyroid (eg goiter)

Symptoms from Corticotropin-secreting Adenoma:

  • Menstrual disturbance
  • High blood pressure
  • High fasting glucose
  • Skin changes (increased facial hair, acne, bruising, bluish stretch marks
  • Buffalo hump (increased fatty tissue in back)
  • Obesity especially around the wrist
  • Round face

Growth Hormone-secreting Adenoma

  • Acromegaly (adult)
  • Gigantism (child)
  • High blood pressure
  • High fasting blood sugar
  • Facial features coarse
  • Oily skin
  • Excess sweating

Pituitary adenomas may also be associated with the following conditions:

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Diagnosis

Your doctor will ask about your symptoms and medical history. A physical exam will be done. You may be referred to an endocrinologist. This is a doctor that focuses on these glands. Tests may include:

  • Blood tests—to measure hormone levels, blood sugar levels (prolactin, TSH, growth hormone, corticotrophin or aCTH, beta human gonadotropin, nsulin-like growth factor-1, alpha subunit), and to identify other underlying conditions that may be causing your symptoms
  • Urine tests—to measure excretion levels of certain pituitary gland hormones (beta human gonadotropin, cortisol)
  • Visual field tests—to check for problems with peripheral vision
  • MRI scan]]> —a test that uses strong magnets and radio waves to create pictures of structures inside the brain

Special Tests

  • Glucose tolerance test—the standard test for acromegaly
  • Dexamethasone suppression test and corticotropin-releasing hormone (CRH) test—best tests to see if excessive secretion of hormones from the adrenal gland is due to a pituitary adenoma

Treatment

Treatment depends on the presence and type of hormones being secreted. It is not uncommon for these treatment options to be used in combination. Talk with your doctor about the best plan for you.

Treatment options include:

Surgery

Surgery is often done to remove the tumor. The pituitary gland may be damaged during surgery. This can be treated with medications. They will replace certain hormones produced by the pituitary.

Medications

Medications can control symptoms and sometimes shrink the tumor. They can block hormone secretion Medications may include:

  • Dopamine agnoists 9eg bromocriptine
  • Octreotide

Radiation Therapy

Radiation therapy involves the use of radiation to 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 (positively charged particles) is directly focused on the tumor

Prevention

There are no guidelines for preventing a pituitary adenoma.