Acromegaly is a rare hormonal disorder that occurs when the pituitary gland at the base of the brain produces excessive amounts of growth hormone (GH). This overproduction of growth hormone leads to abnormal growth and enlargement of bones and soft tissues, particularly in the hands, feet, and face. Acromegaly typically develops gradually over several years, and many people may not recognize the symptoms initially.
Causes of Acromegaly:
The primary cause of acromegaly is a benign (non-cancerous) tumor of the pituitary gland called a pituitary adenoma. These tumors secrete excess growth hormone, which leads to the symptoms of acromegaly. In rare cases, acromegaly can be caused by other factors, such as:
- Genetic mutations: Certain genetic conditions, like McCune-Albright syndrome or Carney complex, can increase the likelihood of developing acromegaly.
- Familial acromegaly: A small percentage of acromegaly cases are inherited, particularly in families with a history of pituitary tumors.
Symptoms of Acromegaly:
Symptoms of acromegaly develop slowly and may not be noticed until the condition has caused significant changes. Common symptoms include:
- Enlargement of hands and feet: Hands and feet may become noticeably larger, and people may have to buy larger shoes or rings. The fingers may appear thickened, and the palms may become wider.
- Facial changes: Over time, the bones in the face, including the jaw, brow, and nose, may enlarge, causing a characteristic facial appearance. Common changes include:
- Protruding jaw (prognathism)
- Enlarged nose
- Thickened lips and coarse facial features
- Increased spacing between teeth due to jaw enlargement
- Joint pain: Acromegaly can cause arthritis and joint pain due to the increased size of bones and tissues.
- Skin changes: The skin may become thick, oily, and sweaty. It can also develop a leathery texture.
- Sleep apnea: The enlarged tissues, particularly in the throat, can lead to breathing difficulties during sleep, resulting in obstructive sleep apnea.
- Excessive sweating: Individuals with acromegaly may experience excessive perspiration and skin oiliness.
- Vision problems: If the tumor presses against nearby structures, such as the optic nerves, it can cause vision problems, including peripheral vision loss.
- Enlarged organs: In some cases, the enlargement of internal organs like the heart, liver, and kidneys can occur.
- Headaches: Increased pressure from the pituitary tumor may lead to persistent headaches.
- Increased soft tissue growth: This can lead to the development of benign growths, such as skin tags or tumors in organs like the colon.
Diagnosis of Acromegaly:
To diagnose acromegaly, doctors typically use a combination of tests:
- Blood tests: Measurement of growth hormone levels and insulin-like growth factor 1 (IGF-1) levels. IGF-1 is produced in response to growth hormone and remains stable throughout the day, making it a reliable indicator of excessive growth hormone levels.
- Oral glucose tolerance test (OGTT): In this test, the patient drinks a glucose solution, and the blood sugar and growth hormone levels are measured at intervals. In acromegaly, growth hormone levels do not suppress as they should after consuming glucose.
- MRI or CT scans: Imaging tests are used to detect the presence of a pituitary tumor. An MRI is the most common imaging technique for assessing pituitary adenomas.
Treatment of Acromegaly:
The goal of treatment is to normalize growth hormone levels and alleviate symptoms. Treatment options include:
- Surgery:
- Transsphenoidal surgery is the most common approach for removing the pituitary tumor. The surgeon accesses the tumor through the nasal passages or under the upper lip.
- In some cases, if the tumor cannot be fully removed or is not accessible, surgery may not completely resolve the condition.
- Medications:
- Somatostatin analogs: These drugs, such as octreotide or lanreotide, inhibit growth hormone production and are often used to manage acromegaly.
- Growth hormone receptor antagonists: Drugs like pegvisomant block the effects of growth hormone at the receptor level.
- Dopamine agonists: Medications like bromocriptine can sometimes shrink pituitary tumors and lower growth hormone levels.
- Radiation therapy:
- If surgery and medications do not fully control growth hormone levels, radiation therapy may be used to shrink the pituitary tumor and reduce growth hormone secretion.
- This approach may take months or even years to show full results and is often used in combination with other treatments.
Complications of Acromegaly:
If left untreated, acromegaly can lead to serious complications, including:
- Cardiovascular issues: Enlargement of the heart (cardiomegaly) can lead to heart disease, high blood pressure, and an increased risk of heart failure.
- Diabetes: High growth hormone levels can interfere with insulin function, increasing the risk of type 2 diabetes.
- Osteoarthritis: The growth of bones and joints can lead to arthritis, limiting mobility and causing joint pain.
- Sleep apnea: Obstructive sleep apnea, which can be life-threatening if untreated, is common in people with acromegaly.
- Increased risk of certain cancers: There may be an increased risk of colon polyps and possibly other types of cancer due to the abnormal cell growth associated with acromegaly.
Prognosis:
With early diagnosis and appropriate treatment, the prognosis for individuals with acromegaly can be favorable. Normalizing growth hormone levels can prevent further complications and reduce the severity of symptoms. However, the condition can be life-threatening if left untreated, especially due to cardiovascular risks and the potential for organ enlargement.
