Acromegaly (called gigantism in children) is a rare condition in which the whole body or parts of the body, particularly the hands and feet, grow larger than normal. More than 95 percent of all cases of acromegaly are the result of a growth hormone–secreting pituitary adenoma.

Growth hormone–secreting pituitary adenomas begin in the somatotropic cells of the pituitary gland. Also called GH, the growth hormone secreted by these tumors triggers the liver to produce insulin-like growth factor 1, or IGF-1. IGF-1 is involved in bone and tissue growth, metabolism, and other processes of the body. When the body produces too much IGF-1, it leads to a range of symptoms known as acromegaly.

The exact cause of growth hormone–secreting tumors is unknown, but acromegaly resulting from a pituitary adenoma is most commonly diagnosed in middle-aged adults.

Most GH-secreting adenomas are benign (not cancer), though in rare cases, they can become cancerous.

Acromegaly Symptoms

Among the most serious symptoms of acromegaly are type 2 diabetes, high blood pressure, increased risk of cardiovascular disease, and arthritis. 

Many tumors are not found until after they have grown large enough to cause disturbances in vision as the tumor presses on the nearby optic nerves.

Other symptoms of acromegaly may include:

• abnormal 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 (acromegaly is sometimes first noticed during a routine visit to the dentist)
• increased sweating
• frequent kidney stones
• headaches

Acromegaly Diagnosis

Acromegaly is diagnosed using blood tests that look for abnormal amounts of growth hormone and insulin-like growth factor I, or IGF-1. 

You may also need to have an MRI scan of the brain, where the pituitary gland is located, to determine the exact size and location of the tumor.

Acromegaly Treatment

The primary treatment for acromegaly caused by a pituitary adenoma is surgery to remove the tumor.

Memorial Sloan Kettering surgeons are experienced in using a minimally invasive approach called transsphenoidal surgery to remove pituitary tumors. The approach allows our surgeons to bypass brain tissue, operating instead through an incision inside the nasal passage. The risk for neurologic complications with this technique is very low, and the surgery leaves no visible scar.

Transsphenoidal Surgery for Pituitary Tumors

The main treatment for most pituitary tumor patients is a minimally invasive operation called transsphenoidal surgery. Learn more about our expertise.

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In the rare case that a tumor is too large to be removed using transsphenoidal surgery, our surgeons may recommend a craniotomy, a procedure in which the tumor is removed through an incision made in the front of the skull.

Sometimes large growth hormone–secreting tumors (macroadenomas) can be difficult to cure with surgery alone and may require additional therapy, such as radiation therapy or certain medications.

Radiation Therapy for Acromegaly

Radiation therapy can be used in one of several ways for acromegaly caused by a pituitary tumor. It may be recommended as additional therapy after surgery to prevent regrowth of the tumor. Radiation may also be used as the sole treatment if the tumor cannot be removed surgically, or if the tumor regrows after surgery.

The radiation therapy team at MSK is highly experienced in caring for people with acromegaly, and works closely with the other members of your care team. They have access to every form of modern radiation therapy available and will customize a treatment plan so precise that it factors in the size and shape of your tumor to the millimeter. 

Their goal is to not only eliminate the tumor cells but to prevent the side effects of treatment by keeping the healthy cells around the tumor safe.

We offer several radiation therapy options for people with acromegaly caused by a pituitary tumor. Learn more about our approach to radiation therapy for pituitary tumors.

Medications for Acromegaly

Some patients receive injections of medications such as octreotide acetate (Sandostatin^®) or lanreotide (Somatuline^®). Usually given once a month, these long-acting drugs work by suppressing growth hormone production. A similar medication, called pasireotide (Signifor^®), was recently approved for the treatment of acromegaly. Another medication, called pegvisomant (Somavert^®), is also effective for certain patients.

Follow-Up Care

It’s important to see your doctor regularly for medical checkups to prevent, detect, and treat any complications resulting from acromegaly. At Memorial Sloan Kettering, we provide long-term follow-up care for our acromegaly patients.

Because people with excess growth hormone are at an increased risk for developing polyps in the colon, we encourage you to speak to your doctor about scheduling regular screening colonoscopies. We will also recommend screening echocardiograms, screening thyroid ultrasounds, and sleep apnea evaluations.

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