Hopkins 24/7

Back to ABC News

This Thursday at 10/9c

This content requires javascript and flash player version 8.

Johns Hopkins Symptoms and Remedies

Johns Hopkins Medicine

Close Article Browser

Acromegaly

What is it?

Acromegaly, known as gigantism in children, is a rare, chronic disorder caused by an over production of growth hormone by the pituitary gland. The pituitary, a peanut-size organ located at the base of the brain, is the most important gland in the body's endocrine, or hormonal, system. It produces a number of essential hormones; one of these, human growth hormone (HGH or somatotropin), is responsible for regulating growth during childhood. Normally, as people reach adulthood, less HGH is produced. Over production of HGH in children results in exaggerated height. (The most dramatic case of gigantism on record is a child who grew to a height of nearly nine feet.) When onset of the disorder occurs during adulthood (acromegaly), bones can no longer increase in length but progressively thicken instead. This results in gradual enlargement of the hands, feet, jaw, forehead, nose, and ears and produces the coarse facial features characteristic of the disorder. The internal organs also become abnormally enlarged. Thus, acromegaly often reduces life expectancy and, if left untreated, may lead to blindness, arthritis, infertility, diabetes, high blood pressure, heart valve failure, and coronary artery disease.

What Causes It?

  • A benign pituitary tumor (adenoma) is the most common cause of HGH over production.
  • Rarely, a tumor in the hypothalamus (the region of the brain directly behind the pituitary gland) or elsewhere may overstimulate production of HGH.

Prevention

  • There is no way to prevent acromegaly.

Diagnosis

  • Patient history and physical examination, including visual-field tests.
  • Blood tests revealing elevated levels of HGH that are not fully reduced by administration of glucose.
  • Measurement of elevated levels of somatomedin-C (IGF-1) in the blood.
  • CT (computed tomography) scans and MRI (magnetic resonance imaging) to detect a pituitary tumor.

How to Treat It

  • Surgical removal of the underlying tumor is the treatment of choice. It is not uncommon for HGH levels to return to normal within hours of surgery and for soft tissue (but not bony tissue) enlargement to subside rapidly.
  • Medications after surgery such as octreotide and sometimes cabergoline may be prescribed to decrease tumor size and regulate HGH secretion.
  • Radiation, alone or following surgery, may be performed to shrink the tumor (or prevent its recurrence) but it may require 5 to 10 years to work.
  • In some cases, lifetime hormone replacement therapy with thyroid or adrenal-steroid hormones may be necessary if surgery or radiation damages the remaining pituitary gland.

When to Call a Doctor

  • See a doctor if you or your child develop symptoms of acromegaly or gigantism.