A pituitary tumor can cause a disease called acromegaly. People with this disease will not only develop thick bones, but acromegaly can lead to several complications as well. The thickened bones can lead to carpal tunnel syndrome. The size of the tumor can cause vision problems. The internal organs increase in size, which can lead to problems such as hypertension and heart failure.
Acromegaly
An adenoma is a benign tumor with structures that resemble a gland. A pituitary adenoma can cause acromegaly. This is a disease that develops in adults because the pituitary adenoma is secreting too much of the growth hormone. Some people with acromegaly will also have tumors in the pancreas and parathyroid gland. If the pituitary adenoma secretes too much growth hormone in a child, the disease is called gigantism.
Symptoms
People with acromegaly may have increased growth in the bones of their skull, and may wonder why they have to get a bigger hat size. Their jaw increases in size, which makes the space between their teeth widen. They usually gain weight because of thicker bones and muscles. Dr. Fitzgerald writes in "Current Medical Diagnosis & Treatment" that even their fingers get wide and they may develop carpal tunnel syndrome. This syndrome is due to a nerve being compressed at the wrist when it passes through the bones of the carpal tunnel. An increased bone thickness leaves less room for the nerve to pass through. People with this syndrome may have wrist pain, tingling and numbness in their fingers.
Evaluation
An MRI or CT scan of the head, or a skull X-ray shows the increased size and thickening of the bones in the skull. An X-ray of the hand shows thickening of the bones of the hand. The pituitary adenoma causes abnormally high levels of growth hormone (GH). But because the GH levels fluctuate, the simplest way to determine the GH levels is to check the levels of IGF-1, or insulin-like growth factor 1. GH stimulates the liver to secrete IGF-1, which does not fluctuate.
Complications
Acromegaly can lead to several complications. The heart, lung, liver, kidneys and spleen all increase in size. People can develop hypertension and heart failure. Their tissues and organs may no longer be as sensitive to insulin as they should be. They may even develop diabetes mellitus. People might develop vision problems or even vision loss. Vision problems can develop if the pituitary adenoma presses on the optic chiasm area in the brain, a place where the optic, or visual, nerves cross.
Prognosis
People with acromegaly have an increased risk of complications and death from heart problems. Treatment lowers this risk. According to Dr. Fitzgerald, surgery is successful in 80 to 90 percent of those with tumors smaller than 2 cm. Radiation therapy is successful in approximately 40 to 77 percent, depending upon the type of radiation. People with this disease need regular monitoring, even after treatment. One complication of surgery and radiation therapy is that the tumor will start secreting abnormally low levels of the hormone.
References
- "Current Medical Diagnosis & Treatment 2010"; Stephen McPhee, M.D., Maxine Papadakis, M.D.; 2010
- Merck Manual Professional: Gigantism and Acromegaly
