Hyperpituitarism is the hypersecretion of human growth hormone (hGH) by the anterior pituitary or adenohypophysis gland. Two distinct conditions may result from hyperpituitarism, depending on the time of life at which this dysfunction begins. Gigantism results from the hypersecretion of hGH during an individual’s growing years, especially before puberty. The person with gigantism grows abnormally tall, although the relative proportion of the body parts and sexual development remain unaffected. When hGH hypersecretion occurs during adulthood, acromegaly results. Acromegaly is a chronic, disfiguring, life-shortening disease characterized by the overgrowth of bones and soft tissues and cardiac dysfunction.
The hypersecretion of hGH that produces gigantism and acromegaly is typically due to benign, slow-growing glandular tumors, or adenomas, in the anterior pituitary. Not subject to normal control, these neoplastic cells release abnormally high levels of hGH. A genetic cause also has been suggested.
Signs and Symptoms
The principal symptom of gigantism is excessive growth of the long bones of the body. It develops abruptly and results in an abnormal increase in height. A child with the condition may grow as much as 6 inches a year.
The symptoms of acromegaly generally appear very gradually, causing the deformation and coarsening of facial features and enlargement of the hands, feet, head, and tongue. Serious physiological symptoms also may appear, such as increased sweating, thick and coarse oily skin, and chronic sinus congestion. The person with acromegaly often complains of headaches; weakness; joint pain; vision disorders; and paresthesia, a sensation of numbness, prickling, or tingling.
The clinical picture of symptoms suggests the diagnosis. A glucose tolerance test is the standard method for confirming elevated hGH levels. Magnetic resonance imaging (MRI) and computed tomography (CT) scans are useful in pinpointing the location and estimating the extent of any pituitary tumor or lesion. Bone x-rays may exhibit bone thickening, especially of the cranium and long bones.
Treatment goals involve lowering hGH levels to normal and stabilizing or removing the underlying tumor while minimizing damage to the pituitary gland itself. Depending on the size and location of the tumor, transsphenoidal (incision through the nose to remove tumor) surgery may be performed. Otherwise, radiation therapy to reduce or destroy the tumor or medication therapy to shut off hGH hormone production may be used.
No significant complementary therapy is indicated.
Clients will be concerned about body changes; therefore, emotional support is very helpful. Remind clients and family members what can happen with this disease, and prepare them for surgery as needed. Hormone replacement therapy following surgery or radiation is necessary and should be regularly monitored by a primary care provider.
The prognosis for an individual with either gigantism or acromegaly depends on how far the condition has advanced before successful treatment. Gigantism is generally not life-threatening, and the prognosis is usually good. An individual with advanced acromegaly, however, may suffer serious complications, such as hypertension, congestive heart failure, type 2 diabetes mellitus, respiratory diseases, or cerebrovascular diseases.
There is no specific prevention for hyperpituitarism. Early treatment helps to prevent complications.