What is pituitary cancer?

The pituitary gland, also called the “master” gland, is a pea-size gland important to the functioning of the human body. It is located behind the eyes and below the front of the brain.

The pituitary gland produces hormones that regulate critical body organs and glands, including the:

  • thyroid gland
  • adrenal glands
  • ovaries
  • testicles

Tumors that form in the pituitary gland are rare and usually noncancerous, or benign. Most are also considered “functioning,” which means that they produce hormones. Tumors that don’t produce hormones are called “nonfunctioning.”

According to the American Cancer Society, few of the 10,000 tumors projected to be diagnosed in 2016 will turn out to be cancerous.

Common types of benign pituitary tumors include:

Adrenocorticotropic hormone-secreting (ACTH) tumors

About 16 percent of pituitary tumors secrete too much of the hormone adrenocorticotropic hormone (ACTH), causing Cushing’s syndrome. Symptoms can include:

  • high blood pressure
  • high blood sugar
  • thinner arms and legs
  • excess fat around the torso

Cushing’s syndrome isn’t always caused by a tumor, but see your doctor for tests if you notice any of the symptoms of an ACTH tumor.

Growth hormone-secreting tumors

These tumors cause your body to produce too much growth hormone. Symptoms can include:

  • high blood sugar
  • growth of excess body hair
  • abnormal sweating
  • abnormal growth of your feet and hands

Prolactin-secreting tumors

These tumors can reduce levels of testosterone in men and estrogen in women. Symptoms can include erectile dysfunction and breast growth in men, and abnormal menstruation and discharge from the breasts in women.

Thyroid-stimulating hormone-secreting tumors

These tumors can cause hyperthyroidism and increase your metabolism. Symptoms can include:

  • abnormal sweating
  • irregular heart rate
  • abnormal weight loss
  • abnormal bowel movements

Learn more: Pituitary-dependent Cushing’s disease »

Pituitary cancer (pituitary carcinoma) is rare. Only a few hundred cases of pituitary cancers have ever been recorded in the United States. Most were diagnosed in older people and about 75 percent of cases were diagnosed after death.

Benign tumors account for about 30 to 40 percent of all pituitary tumors, according to the American Brain Tumor Association. They are most common in young, reproductive-age women and men in their 40s and 50s.

One in 4 people may have a benign pituitary tumor (adenoma) and not even know it because the tumor is noncancerous and doesn’t cause any symptoms.

Pituitary tumors are often considered brain tumors, and they make up 12 to 19 percent of all primary brain tumors. But most pituitary tumors are benign and most of them are treatable.

Symptoms experienced due to a pituitary tumor depend on their size and the hormones they release.

Symptoms common to any pituitary tumor can include:

  • headache
  • vision loss
  • seizures

Other symptoms specific to certain kinds of pituitary tumors can include:

  • weight gain
  • bruising easily
  • irritability, anxiety, and depression
  • nausea and vomiting
  • dizziness
  • confusion
  • flushing of the face
  • weak muscles and bones
  • high blood pressure
  • irregular heartbeat
  • large hands and feet (acromegaly)
  • producing breast milk even if not pregnant
  • lack of milk when breast-feeding
  • menstrual cycle changes
  • lowered sex drive
  • impotence
  • loss of body hair
  • abnormal sexual development and growth in children

MRI or CT scans can detect tumors in the pituitary gland. And blood and urine tests can determine hormone levels.

Even under a microscope, it’s difficult to recognize the difference between a cancerous and a noncancerous pituitary tumor. A cancerous tumor may not be recognized until it spreads into another part of the body.

Pituitary cancer spreads equally to areas both inside the brain and outside the brain. Common sites of spread (metastasis) include:

  • other parts of the brain and brain blood vessels
  • spinal cord
  • meninges, which cover the brain and spinal cord
  • nearby bone
  • eyes
  • lymph nodes
  • organs such as the lungs, heart, liver, pancreas, kidneys, and ovaries

With most cancers, tumors are staged at the time of diagnosis. The stage is determined by how large the cancer is and to what extent it has spread.

Staging is used to plan a treatment plan and to help determine the outlook. But pituitary cancer is so rare there are actually no universal guidelines for staging or treatment.

Treatment for pituitary cancer depends on the size of the tumor and whether it has spread.

Without a staging system, doctors must try to determine whether the tumor:

  • is smaller than 10 millimeters (microadenoma) or larger than 10 millimeters (macroadenoma)
  • produces hormones
  • has spread to other sites

Treatment options include:

  • surgery
  • radiation therapy
  • chemotherapy
  • hormonal medications

Surgery removes the pituitary gland, while radiation kills microscopic cells that may have been left behind. In some cases, drug therapies are used to shrink and destroy the tumor or decrease the amount of hormones the tumor is producing. Early diagnosis and treatment are essential.

Also, making certain lifestyle changes during and after treatments may improve your outlook and quality of life:

  • Avoid smoking and drinking excessive amounts of alcohol.
  • Follow your doctor’s guidelines regarding exercise.
  • Make healthy, well-balanced diet choices. Eat a variety of fruits, vegetables, and lean proteins, and avoid processed foods.
  • Get plenty of sleep and relax often to prevent fatigue. Consider meditation and yoga.

Cancer treatments can make you feel weak. Healthy eating, along with stress reduction can help you feel energized and positive while being treated for your pituitary cancer.

Cancer left untreated can decrease your quality life or be fatal. Be sure you understand and follow the treatment regimen recommended by your doctor. You will need to work together with a team of healthcare providers that usually include neurosurgeons, oncologists, endocrinologists, nutritionists, and physical therapists.

If you undergo surgery to remove a pituitary tumor, there is some risk of infection or a reaction to anesthesia. Other risks of pituitary surgery include:

  • problems with your vision because of eye nerves being damaged during surgery
  • heavy bleeding into the brain or nose if blood vessels are damaged
  • damage to other parts of the pituitary gland, which can cause additional symptoms

Rare complications include:

  • cerebrospinal fluid (CSF) leaking from the brain out of the nose
  • meningitis, an inflammation of the membranes around the spinal cord and brain

These complications can usually be corrected and don’t always cause lasting damage.

If you have surgery, you may experience congestion in your nose, sinus pressure, and general fatigue for the first few weeks.

You will likely need radiation therapy after surgery for further treatment of pituitary cancer. And you may also need hormone therapy or other medications suggested by an endocrinologist.

The outlook for people with pituitary cancer is based on the spread of the tumor. It is often diagnosed late in its course after the cancer has spread. But research on the best treatment course for pituitary cancer continues.