Definition

The pituitary is a small complicated gland at the base of the brain. It makes several important hormones that regulate growth and the activity of several other major glands throughout the body. A pituitary adenoma is an abnormal growth, or tumor, in this gland. Pituitary adenomas are usually benign. This means they are not cancerous. They do not spread to other parts of the body. The growths can lead to vision problems because it is near the eyes. It can also lead to growth problems. It often can also disrupt the hormonal balance of the thyroid, adrenal, and gonads.

Pituitary Gland

Nucleus factsheet image

Copyright © Nucleus Medical Media, Inc.

Causes

The cause is unknown. Some tumors are part of other endocrine disorders and are associated with genetic changes. These can be inherited.

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

Risk Factors

Factors that may 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 and pancreatic tumors
  • Other inherited disorders such as Carney complex or acromegaly (giantism)
  • Symptoms

    Symptoms can vary and may not be present at all. It will depend on whether the tumor is secreting hormones and how large it is. The tumor's location at the base of the brain can also cause symptoms.

    General symptoms due to size may include:

        
  • Headache
  • Blurred vision or tunnel vision
  • In addition to the above, symptoms from Prolactin Secreting Adenoma:

        
  • Milk production in nonlactating women
  • Loss of or irregular periods
  • Lack of interest in sex
  • Vaginal dryness
  • Symptoms from Thyrotropin-secreting Adenoma

        
  • Swelling of the neck
  • Symptoms of hyperthyroidism

        
  • Tremors
  • Rapid heartbeat
  • Anxiety
  • Weight loss
  • Insomnia
  • Symptoms from Corticotropin-secreting Adenoma:

        
  • Menstrual disturbance
  • Skin changes—increased facial hair, acne, bruising, or bluish stretch marks
  • Buffalo hump—increased fatty tissue in back
  • Obesity, especially around the wrist
  • Round face
  • Growth Hormone-secreting Adenoma

        
  • Enlarged hands and feet
  • Excessive growth and height
  • Oily skin
  • Excess sweating
  • Pituitary adenomas may also be associated with the following conditions:

        
  • Diabetes mellitus
  • Kidney stones
  • Cardiovascular disease
  • High blood pressure
  • Osteoporosis
  • Thyroid disease
  • Diagnosis

    You will be asked about your symptoms and medical history. A physical exam will be done. You will be referred to an endocrinologist. This is a doctor who specializes in glands and hormones.

    Your bodily fluids may be tested. This can be done with:

        
  • Blood tests
  • Urine tests
  • Your peripheral vision may be tested. This can be done with visual field tests.

    Images may be taken of your bodily structures. This can be done with an MRI scan.

    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 rest of the normal pituitary gland may be damaged during surgery. This can be treated by replacing the missing hormones with pills or other forms of hormone replacement.

    Medications

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

    For the majority of adenomas, that are prolactin or growth hormone secreting, medications may include:

        
  • Dopamine agonists—cabergoline, bromocriptine
  • Octreotide or long-acting versions
  • 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.