A pituitary tumor can cause your pituitary gland to produce too much or too few hormones, which can cause problems in your body. Large pituitary tumors — those measuring about 1 centimeter (slightly less than a half-inch) or larger — are known as macroadenomas. Smaller tumors are called microadenomas. Macroadenomas can put pressure on the rest of the pituitary gland and nearby structures.

Symptoms related to tumor pressure

Signs and symptoms of pressure from a pituitary tumor may include:

  • Headache
  • Vision loss, particularly loss of peripheral vision
  • Nausea and vomiting
  • Symptoms of pituitary hormone deficiency
  • Weakness
  • Less frequent or no menstrual periods
  • Body hair loss
  • Sexual dysfunction
  • Increased frequency and amount of urination
  • Unintended weight loss or gain

Symptoms related to hormone level changes

Some pituitary tumors, called functioning tumors, also produce hormones, generally causing an overproduction of hormones. Different types of functioning tumors can develop in your pituitary gland, each causing specific signs and symptoms and sometimes a combination of them.

Adrenocorticotropic hormone-secreting (ACTH) tumors

ACTH tumors produce the hormone adrenocorticotropin, which stimulates your adrenal glands to make the hormone cortisol. Cushing's syndrome results from your adrenal glands producing too much cortisol. Signs and symptoms of Cushing's syndrome may include:

  • Fat accumulation around your midsection and upper back
  • Exaggerated facial roundness
  • A characteristic hump on the upper part of your back
  • High blood pressure
  • High blood sugar
  • Muscle weakness
  • Bruising
  • Stretch marks
  • Thinning of your skin
  • Anxiety, irritability or depression

Growth hormone-secreting tumors

These tumors produce excess growth hormone. The effects from excess growth hormone (acromegaly) may include:

  • Coarsened facial features
  • Enlarged hands and feet
  • Excess sweating
  • High blood sugar
  • Heart problems
  • Joint pain
  • Misaligned teeth
  • Increased growth of body hair

Accelerated and excessive linear growth may occur in children and adolescents.

Prolactin-secreting tumors

Overproduction of prolactin from a pituitary tumor (prolactinoma) can cause a decrease in normal levels of sex hormones — estrogen in women and testosterone in men. Excessive prolactin in the blood can affect men and women differently.

In women, prolactinoma may cause:

  • Irregular menstrual periods
  • Lack of menstrual periods
  • Milky discharge from the breasts

In men, a prolactin-producing tumor may cause male hypogonadism. Signs and symptoms may include:

  • Erectile dysfunction (ED)
  • Infertilituy
  • Loss of sex drive

Thyroid-stimulating hormone-secreting tumors

When a pituitary tumor overproduces thyroid-stimulating hormone, your thyroid gland makes too much of the hormone thyroxine. This is a rare cause of hyperthyroidism or overactive thyroid disease. Hyperthyroidism can accelerate your body's metabolism, causing:

  • Sudden weight loss
  • Rapid or irregular heartbeat
  • Nervousness or irritability
  • Frequent bowel movements
  • Feeling warm or hot

When to see a doctor

If you develop signs and symptoms that may be associated with a pituitary tumor, see your doctor to determine if this is the cause of your symptoms. Pituitary tumors often can be treated effectively to return your hormone levels to normal and alleviate your signs and symptoms.

If you know that multiple endocrine neoplasia, type I (MEN I) runs in your family, talk to your doctor about periodic tests that may help detect a pituitary tumor early.

Nov. 14, 2012

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