Acromegaly (ak-roh-MEG-uh-lee) is a rare hormonal disorder that develops when your pituitary gland produces too much growth hormone, nearly always as a result of a noncancerous (benign) tumor. The excess hormone causes swelling, skin thickening, tissue growth and bone enlargement, especially in your face, hands and feet.
Acromegaly occurs in adulthood, usually during middle age. In children who are still growing, too much growth hormone can cause a condition called gigantism that leads to an abnormal increase in height as well as excess bone growth.
Because acromegaly is uncommon and physical changes occur gradually, it often isn’t recognized right away. Although untreated acromegaly can lead to serious illness and premature death, available treatments can reduce your risk of complications and significantly improve your symptoms.
One of the most common symptoms of acromegaly is enlarged hands and feet. You may notice that your rings no longer fit and that your shoe size or width has increased. Joint and back pain also are common.
Acromegaly may also cause gradual changes in the shape of your face, such as a protruding lower jaw and brow, an enlarged nose, thickened lips, and wider spacing between your teeth. Because acromegaly tends to progress slowly, symptoms may remain undetected for up to 10 years. People sometimes notice changes only by comparing their current appearance to old photographs.
Typical signs and symptoms of acromegaly include:
- Enlarged hands and feet
- Larger and broader facial features
- Protrusion of the lower jaw so the lower teeth extend beyond the upper teeth (underbite)
- Thickened, oily skin
- Excessive sweating and body odor
- Small skin outgrowths (skin tags)
- Fatigue and muscle weakness
- A deepened, husky voice due to enlarged vocal cords and sinuses
- Severe snoring and frequent brief interruptions in nighttime breathing (sleep apnea) due to tissue swelling that blocks your upper airway
- Impaired vision
- Enlarged tongue
- Back pain
- Pain and limited mobility in joints
- Menstrual cycle irregularities in women
- Reduced sex drive and, in men, trouble achieving or maintaining an erection (erectile dysfunction)
- Enlarged liver, heart, kidneys, spleen and other organs
- Increased chest size (barrel chest)
When to see a doctor
If you notice any long-term changes in your appearance or other symptoms you think may be associated with acromegaly, contact your doctor.
Acromegaly usually develops slowly, and even your family members may not initially notice the gradual physical changes that have occurred. Timely diagnosis is important, though, so that you can receive proper care. Acromegaly can lead to serious complications if it’s not treated.
Acromegaly occurs when your body produces too much growth hormone. The source of the excess hormone is almost always your pituitary gland, a small bean-shaped structure at the base of your brain behind your nose. Growth hormone is one of several hormones your pituitary gland produces.
Growth hormone plays an important role in growth and regeneration of your bones and other tissues by stimulating your liver to produce another hormone called insulin-like growth factor-I (IGF-I).
In adults, a tumor is the most common cause of excess growth hormone:
- Pituitary tumors.Most cases of acromegaly are caused by a noncancerous (benign) tumor, or adenoma, of the pituitary gland. In addition to producing excess growth hormone, these tumors can press on nearby tissues as they grow. This pressure can cause some of the symptoms of acromegaly, such as headaches and impaired vision.
- Nonpituitary tumors.In a few people, acromegaly is caused by benign or cancerous tumors in other parts of the body, such as the lungs, pancreas or adrenal glands. Some of these tumors actually secrete growth hormone. In other cases, they produce a hormone called growth hormone-releasing hormone (GH-RH), which stimulates the pituitary gland to make more growth hormone.
Progression of acromegaly can result in serious health problems. Complications may include:
- High blood pressure (hypertension)
- Heart disease, particularly enlargement of the heart muscle (cardiomyopathy)
- Precancerous growths (polyps) in your colon
- Sleep apnea, a condition in which breathing repeatedly stops and starts during sleep
- Carpal tunnel syndrome — tingling or pain in your fingers caused by excess wrist tissue pressing on nerves
- Reduced production of other pituitary hormones (hypopituitarism)
- Benign tumors in the uterus (uterine fibroids)
- Spinal cord compression
- Vision loss
Early treatment of acromegaly can prevent these complications from developing or becoming worse. If untreated, acromegaly and its complications can lead to premature death.
Preparing for your appointment
You’re likely to start by seeing your family doctor or a general practitioner. If your doctor suspects you have acromegaly, you may be referred to a doctor who specializes in hormonal disorders (endocrinologist).
Because appointments can be brief, and because there’s often a lot of ground to cover, it’s a good idea to be well prepared. Here are some suggestions to help you get ready for your appointment and understand what to expect from your doctor.
What you can do
- Be aware of any pre-appointment restrictions.When you make your appointment, ask if you need to fast for blood work or if there’s anything else you need to do to prepare for diagnostic tests.
- Write down all of your symptoms.Your doctor will want to know about anything that’s causing you discomfort or concern, such as changes in your appearance, headaches, vision issues, or enlargement of your hands and feet. Report symptoms even if they seem unrelated to the reason for which you scheduled the appointment.
- Write down key personal information,including any changes in your sex life or, if you’re a woman, in your menstrual cycle.
- Make a list of all medications,including over-the-counter drugs and vitamins or supplements that you’re taking.
- Bring old photographsthat your doctor can compare with your appearance today. Photos from as far back as 10 years ago through the present may be helpful.
- Take along a family member or friend, if possible.Sometimes it can be difficult to soak up all the information provided to you during an appointment. Someone who accompanies you may remember something that you missed or forgot.
Questions to ask your doctor
Because time with your doctor is limited, writing down a list of questions will help you make the most of your appointment. List your questions from most important to least important in case time runs out. For acromegaly, some questions to ask your doctor include:
- Is acromegaly the most likely cause of my symptoms?
- Are there other possible causes of my symptoms?
- What tests do I need?
- What treatments are available for acromegaly? Which approach do you recommend that I try first?
- How long will I need treatment before my symptoms improve?
- With treatment, will I go back to looking and feeling as I did before I developed symptoms of acromegaly?
- Should I expect any long-term complications?
- If I have acromegaly, will it affect how I manage my other health conditions?
- Are there any restrictions I need to follow?
- Should I see a specialist? What will that cost? Will my insurance cover it?
- Is there a generic alternative to the medicine you’re prescribing me?
- Do you have any brochures or other printed material I can take home with me? What websites do you recommend?
In addition to the questions you’ve prepared ahead of time, don’t hesitate to ask your doctor to clarify anything you don’t understand.
What to expect from your doctor
Your doctor is also likely to have questions for you. Being ready to respond may free up time to focus on any points you want to talk about in depth. Your doctor may ask:
- What symptoms are you experiencing? When did they first appear?
- Have you noticed any changes in how you feel or how you look? Has your sex life changed? How are you sleeping? Do you have headaches or joint pain, or has your vision changed? Have you noticed excessive sweating?
- Does anything seem to make your symptoms better or worse?
- How much would you say your features have changed over time? Do you have old photographs I can see for comparison?
- Have you noticed any changes in the way your shoes or rings fit? How much has the fit changed over time?
- Have you ever had colon cancer screening?
Tests and diagnosis
As a first step toward diagnosis, your doctor will take a complete medical history and conduct a physical exam. Then he or she may recommend the following steps:
- Measuring IGF-1.Because growth hormone stimulates your liver to produce IGF-1 — another growth hormone — IGF-1 blood levels are nearly always elevated when you have acromegaly.
- Measuring growth hormone before and after you drink glucose.Your doctor may also test your growth hormone levels to confirm that you have acromegaly. In this test, your blood levels of growth hormone are measured both before and at several points after you drink a preparation of sugar (glucose). Normally, taking in glucose causes growth hormone levels to fall. But if your body is producing too much growth hormone, levels stay high.
- Imaging.After acromegaly has been diagnosed by measuring your IGF-1 and growth hormone levels, your doctor will likely recommend magnetic resonance imaging (MRI) of your brain to pinpoint the size and location of your tumor. Brain imaging may sometimes be performed with computerized tomography (CT). If brain imaging fails to detect a pituitary tumor, your doctor may recommend additional blood work and further imaging studies of your chest or abdomen.
Treatments and drugs
Doctors treat acromegaly caused by benign tumors of the pituitary gland with surgery, medications and radiation. Your initial care plan will depend on your age, the size and location of your tumor, and other medical conditions you may have. Over time, you may need more than one type of treatment. The goal of therapy is to return your growth hormone and IGF-1 levels as close to normal as possible to avoid serious complications and eliminate the risk of premature death. With successful treatment, swelling and enlargement of your soft tissues may gradually subside. Treatment can’t reverse excess bone growth, but it can prevent more growth from occurring.
If your acromegaly is caused by a tumor outside your pituitary gland, your doctor will develop an individualized treatment plan based on the tumor’s location and whether it is benign or cancerous.
Doctors can remove many pituitary tumors using transsphenoidal surgery. In this procedure, named for the sphenoid sinus — air pocket behind the nose — your surgeon extracts your tumor through a small incision through the back wall of your nose.
Because transsphenoidal surgery is complex, it’s important to choose a surgeon experienced in performing this procedure. Research has shown that more-experienced surgeons who perform greater numbers of procedures generally have more successful outcomes.
Removing the tumor surgically can quickly and effectively return growth hormone levels to normal and relieve pressure on the tissues around your pituitary gland. But even the most experienced surgeon may not be able to completely remove tumors that have grown large or extended into nearby blood vessels or other structures. Incomplete tumor removal may result in growth hormone levels that stay high after surgery, requiring further treatment with medication or radiation.
Doctors may choose to manage your acromegaly with medication if your pituitary tumor is inaccessible to surgery, or you’re at high risk of surgical complications. You may also need drugs if your growth hormone levels stay high following surgery. Your need for medications may continue for the rest of your life. Drugs used to lower the production of growth hormone or block its action on target tissues include:
- Somatostatin analogues (SSAs).The drugs octreotide (Sandostatin, Sandostatin LAR) and lanreotide (Somatuline Depot) are synthetic versions of the brain hormone somatostatin — growth hormone release-inhibiting hormone. They can decrease growth hormone levels by blocking the pituitary gland’s excess production. They can also shrink tumors over time. When starting octreotide treatment, you initially inject yourself with a short-acting preparation under your skin (subcutaneously) every eight hours to determine if you have any side effects from the medication and if it’s effective. Then, if it’s tolerated and effective, you can take a long-acting form that requires an injection into the muscles of your buttocks (gluteal muscles) by a health care professional, administered once a month. Lanreotide is given as a long-acting subcutaneous injection once a month. Your health care professional may give the injection or teach you or a family member how to do it. Common side effects of SSAs include pain at the injection site, intestinal cramping and diarrhea, and gallbladder problems.
- Growth hormone receptor antagonists (GHRAs).The medication pegvisomant (Somavert) blocks the effect of growth hormone on body tissues. You administer pegvisomant yourself daily by subcutaneous injection. This medication can normalize IGF-I levels and relieve symptoms in most people with acromegaly, but doesn’t lower growth hormone levels or reduce the tumor size. Common side effects include headache, fatigue, nausea and diarrhea.
- Dopamine agonists.Cabergoline (Dostinex) and bromocriptine (Parlodel) offer another strategy to reduce growth hormone production and shrink tumors. Both drugs can be taken as pills, but are effective for significantly fewer people than are somatostatin analogues or growth hormone receptor antagonists. Doctors sometimes prescribe treatment combining dopamine agonists with somatostatin analogues. Common side effects of dopamine agonists include nausea, intestinal cramps and headache.
Your doctor may recommend radiation treatment if tumor cells remain after surgery and medication is ineffective in reducing your growth hormone levels. Radiation therapy can quickly stop lingering tumor cells from growing and slowly reduce growth hormone levels. It may take years for this treatment to noticeably improve acromegaly symptoms, and you may continue to need medication while you and your doctor wait for your growth hormone levels to fall.
You receive radiation treatment in one of two ways:
- Conventional radiation therapy.This type of radiation is usually given every weekday over four to six weeks. It may take five to 10 years or more for your growth hormone levels to return to normal.
- Stereotactic radiosurgery.Radiation can also be given stereotactically, with precisely focused, intense beams aimed at a tumor from multiple directions. This strategy can deliver a high dose of radiation to tumor cells while limiting the amount of radiation to nearby normal tissues.Current stereotactic technologies deliver radiation with a gamma knife, a linear accelerator or a proton beam. These treatments may be given in a single session or multiple sessions. Emerging evidence suggests that stereotactic approaches may bring growth hormone levels back to normal within three to five years.Stereotactic radiosurgery is available at a limited number of U.S. medical centers. Pituitary tumors that are too close to the point where the eye (optic) nerves cross are not eligible for stereotactic surgery. Your doctor will determine which type of radiation therapy is right for you.
After your treatment for acromegaly, you’ll require monitoring by your doctor to make sure that your pituitary gland is functioning properly and that your symptoms are getting better. This follow-up care may last the rest of your life. Because acromegaly is linked to a risk of precancerous colon polyps, you should have a screening colonoscopy close to the time of your diagnosis and at recommended intervals afterwards.