Acromegaly
Definition
Growth hormone (GH) controls the growth of soft tissue and bone. Elevated GH causes an excess of bone and soft tissue growth. In adults, this can cause the rare disorders acromegaly. It can cause serious complications and early death if not treated.
In young children, bone fusion and growth is still occurring. Excess GH can cause a similar condition called gigantism.
Causes
The pituitary gland is a small gland located at the base of the brain. It produces many hormones including GH.
In most cases, the elevation of GH is caused by a benign tumor of this gland. In a small number of cases, malignant tumors of other organs (pancreas, adrenal, lung) may be the source of excess GH.
Pituitary Gland
Risk Factors
- In some rare cases—family history
- Average age of diagnosis is 40-45 years old
Symptoms
Symptoms usually develop very slowly over time.
In children, the bones are elongated and cause soft tissue swelling. If not treated, children can grow to a height of 7-8 feet.
Symptoms and complications in adults may include the following:
-
Abnormally large growth and deformity of the:
- Hands (rings no longer fit)
- Feet (need a bigger size shoe)
- Face (protrusion of brow and lower jaw)
- Jaw (teeth do not line up correctly when the mouth is closed)
- Lips
- Tongue
- Carpal tunnel syndrome
-
Skin changes, such as:
- Thickened, oily, and sometimes darkened skin
- Severe acne
- Excessive sweating and offensive body order due to enlargement of the sweat glands
- Deepening voice due to enlarged sinuses, vocal cords, and soft tissues of the throat
- Fatigue and weakness in legs and arms
- Sleep apnea
- Arthritis and other joint problems especially in the jaw
- Hypothyroidism
-
Enlargement of the liver, kidneys, spleen, heart, and/or other internal organs, which can lead to:
- Diabetes
- High blood pressure
- Cardiovascular disease
-
In women:
- Irregular menstrual cycles
- Galactorrhea (abnormal production of breast milk) in about 50% of cases
-
In men:
- Impotence in about 50% of cases
Diagnosis
The doctor will ask about your symptoms and medical history. A physical exam will be done. It is often not diagnosed until years after its onset.
Blood tests will be done to measure the level of:
- Insulin-like growth factor (IGF-I)
- Growth hormone releasing hormone (GHRH)
- Other pituitary hormones
A glucose tolerance test may also be given to see if the GH level drops. It will not drop in cases of acromegaly.
If these tests confirm acromegaly, the following may be done to locate the tumor that is causing the disorder:
- Head CT scan —a type of x-ray that uses a computer to make pictures of the inside of the brain and surrounding structures
- MRI scan —a test that uses magnetic waves to make pictures of the inside of the body, in this case the head
Treatment
The goals of treatment are to:
- Reduce production of GH to normal levels
- Stop and reverse the symptoms caused by oversecretion of GH
- Correct other endocrine abnormalities (thyroid, adrenal, sex organs)
- Reduce the tumor size
Treatment may include:
Surgery
The tumor that is believed to be causing acromegaly may be removed. In most cases, this is the preferred treatment. However, drug treatment is becoming more popular as the primary treatment approach.
Radiotherapy
External beams of radiation are used to shrink the tumor. It is most often used when surgery cannot be used or when medications have failed.
Medication
Drugs may be given to reduce the level of GH secretion. These include:
- Cabergoline (Dostinex)—given orally
- Pergolide (Permax)—given orally
- Bromocriptine (Parlodel)—may be given before surgery to shrink tumor
- Octreotide (Sandostatin)—given by injections (may be the most effective medication for this condition)
- Pegvisomant —given by injections if not responding to other forms of treatment
Prevention
There are no known steps to prevent acromegaly. Early treatment will help to prevent serious complications.
Resources:
National Institute of Diabetes & Digestive & Kidney Diseases
The Neuroendocrine Clinical Center and Pituitary Tumor Center
Pituitary Network Association
Canadian Resources:
Health Canada
Queen's University Department of Ophthamology
References:
Abrams P, Alexopoulou O, Abs R, et al. Optimalization and cost management of lanreotide-Autogel therapy in acromegaly. Eur J Endocrinol. 2007;571-577.
Acromegaly treatment consensus workshop participants: guidelines for acromegaly management. J Clin Endocrinol Metab. 2002; 87:4054-4058.
American Academy of Family Physicians website. Available at: http://www.aafp.org.
Cook DM. AACE Acromegaly Guidelines Taskforce. American Association of Clinical Endocrinologists medical guidelines for clinical practice for the diagnosis and treatment of acromegaly. Endoc Pract. 2004;10:213-225.
Glustina A, Barkan A, Casanueva FF, et al. Criteria for cure of acromegaly: a consensus statement. J Clin Endocrinol Metab. 2000;85:526-529.
Katznelson L, Atkinson JL, Cook DM, Ezzat SZ, Hamrahian AH, Miller KK. American association of clinical endocrinologists medical guidelines for clinical practice for the diagnosis and treatment of acromegaly - 2011 update: executive summary. Endocr Pract. 2011;17(4):636-646.
Melmed S. Medical progress: acromegaly. N Engl J Med. 2006;355:2558-2573.
The Merck Manual of Medical Information. Simon and Schuster; 2000.
National Institute of Diabetes & Digestive & Kidney Diseases website. Available at: http://www.niddk.nih.gov.
Paisley AN, Trainer PJ. Medical treatment in acromegaly. Curr Opin Pharmacol. 2003;3:672-677.
Sherlock M, Woods C, Sheppard MC. Medical therapy in acromegaly. Nat Rev Endocrinol. 2011;7(5):291-300.
Trainer PJ, Drake WM, Katzneison L, et al. Treatment of acromegaly with the growth hormone-receptor antagonist pegvisomant. N Engl J Med. 2000; 342:1171-1177.
Last reviewed September 2011 by Lawrence Frisch, MD, MPH
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.