These tumors make growth hormone, which can cause a disorder known as acromegaly (in adults) or gigantism (in children) when too much is made. They are equally common in men and women. Growth-hormone-producing tumors account for 15 to 20 percent of pituitary tumors. They are most commonly found around age 19 or 20 (when they can grow quite rapidly) or in adults ages 50 to 55 (when the onset is more gradual).
Symptoms
Most growth-hormone-secreting tumors are macroadenomas and may cause vision disturbances because they press on the nearby optic nerve. The overproduction of growth hormone in children may cause gigantism, the effects of which may include:
- being very tall (sometimes over 7 feet)
- very rapid growth
- joint pain
- increased sweating.
In adults, growth-hormone-secreting tumors may cause acromegaly, whose features may include:
- growth of the skull, hands, and feet
- deepening of the voice
- a change in the appearance of the face as facial bones grow
- an increase in spacing between the teeth as the jawbone grows (leading acromegaly to sometimes be first noticed by a patient’s dentist)
- joint pain
- increased sweating
- diabetes
- kidney stones
- heart disease
- headaches
Diagnosis
If your doctor suspects a growth-hormone-secreting tumor, a blood test may be ordered to measure your growth hormone levels. MRI may also be used to visualize the tumor.
Treatment
Surgery to remove the tumor is the primary therapy for growth-hormone-secreting tumors. Surgery for pituitary tumors is often performed through a minimally invasive approach called transphenoidal transnasal resection, in which the surgeon removes the tumor through an incision in the nasal passage. In cases where the tumor is too large to be removed through this approach, the surgeon performs a craniotomy, removing the tumor through an incision in the front of the skull.
If surgery alone is not curative, you may also have radiation therapy. Two of the main types of therapy used for these tumors are radiosurgery and intensity-modulated radiation treatment (IMRT).
Radiosurgery, or stereotaxic radiosurgery, is a type of external radiation therapy that uses special equipment to give a single large dose of radiation to a tumor. IMRT uses radiation beams of varying intensity created to match specific tumor angles and shapes so that the tumor is targeted as precisely and uniformly as possible. This helps to reduce the damage to delicate structures in the area, such as the optic nerves.
Some patients receive injections of octreotide acetate (Sandostatin®). Typically given just once a month, this long-acting medication works by suppressing growth hormone production. Another medication called pegvisomant (Somavert®) is also effective in certain patients.
Follow-Up
Your doctor will see you periodically and perform certain tests to ensure that your pituitary tumor has not returned. If medication is part of your treatment, you may need to take it for the rest of your life to prevent tumor recurrence.
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