Diagnosing Acromegaly

Diagnosing acromegaly can present with significant challenges and often results in delays spanning several years. This rare hormonal disorder, characterized by excessive growth hormone production, manifests through gradual and subtle signs and symptoms, including changes in facial features and enlargement of the hands and feet.

The primary culprit is typically a benign growth in the pituitary gland called a pituitary adenoma. Timely diagnosis is paramount to mitigate symptom progression and potential complications. In this review, we outline the diagnostic process for identifying this disorder.

The first step towards diagnosis is to recognize the signs and symptoms. However, this can be challenging for acromegaly, as excessive growth hormone production can affect multiple systems in the body leading to a variety of symptoms. Additionally, a large pituitary adenoma can compress nearby nerves and brain tissues, causing headache and vision problems.

The hallmark physical manifestation of acromegaly is enlargement of the hands and feet, along with changes in facial features. The nose may become broadened and thickened, lips may enlarge, and the tongue can also increase in size, leading to speech and swallowing difficulties.

Overgrowth of facial bones can also result in a prominent brow ridge and lower jaw, giving the face a more square-like appearance. These features often progress slowly over time and may not be noticeable particularly in the early stages of the condition. Other symptoms can include the following:

• Sweaty, oily skin
• Skin tags (small benign growths)
• Headaches
• Deepened voice
• Muscle weakness and fatigue
• Joint pain
• Sleep apnea

Diagnosing acromegaly typically involves a review of the patient’s medical history, a physical examination, and laboratory testing. It is important to note that acromegaly is often misdiagnosed or underdiagnosed, because its symptoms can develop slowly over a long period of time and be attributed to other conditions. Acromegaly is usually diagnosed more than 3 years after the onset of the condition.

A physician, oftentimes specializing in the diagnosis and treatment of disorders related to hormonal dysfunction (endocrinologist), will obtain the patient’s detailed medical history, including any symptoms that the patient has been experiencing, family history, and past medical conditions and/or treatments. 

A thorough physical examination will be conducted, paying particular attention to any physical signs associated with acromegaly. The most common presenting symptoms in patients with acromegaly are enlarged hands and feet and changes in facial features. Bringing past photos can also be helpful to highlight physical changes.

Several blood tests will be performed to confirm the diagnosis. Elevated levels of insulin-like growth factor 1 (IGF-1) raises suspicion for acromegaly. This is a hormone that is produced in response to growth hormone and will be high in patients with acromegaly.

An oral glucose tolerance test is the confirmatory test for the diagnosis of acromegaly. In this test, the patient drinks a solution containing a known amount of glucose, and blood samples are taken at timed intervals to measure the levels of growth hormone.

In healthy people, the growth hormone level decreases after glucose ingestion, but in a person with acromegaly, the growth hormone level remains elevated. The oral glucose tolerance and IGF-1 tests remain the gold standard for diagnosing acromegaly.

Imaging studies of the brain, such as magnetic resonance imaging (MRI) can be performed to visualize the pituitary gland and detect any tumor or structural abnormality that could be causing excessive growth hormone production.

If no pituitary tumor is seen, computed tomography (CT) scans of the chest and abdomen can be conducted to search for any rare tumors that might be causing an increased growth hormone level.

In some cases, additional tests are conducted to further evaluate complications or other health conditions related to acromegaly. Such tests include a sleep study to assess for sleep apnea, electrocardiography (ECG) to detect potential heart complications associated with the disorder, and a bone density (dual x-ray absorptiometry) test to assess the risk of bone fractures. These tests provide valuable additional information to health care professionals in the comprehensive evaluation and management of acromegaly.

Although it can develop at any age, acromegaly is commonly identified in middle-aged adults between 30 and 50 years of age. However, the onset of symptoms can be slow, and diagnosis can be delayed by several years.

In some cases, patients might not receive the diagnosis until they are in their 50s or 60s. In some studies, acromegaly appears to be more common in women than in men, particularly in younger individuals.

Early diagnosis and treatment are important for minimizing the risk of complications and improving long-term outcomes.

Treatment options for acromegaly include surgery, radiation therapy, and medication. Transsphenoidal surgery is typically the first treatment option recommended.

Transsphenoidal surgery is a minimally invasive procedure that involves removing the pituitary tumor responsible for excessive growth hormone production by using long instruments inserted through the nose. Success rates ranging from 70% to 80% have been reported for this treatment.

When the tumor has not been removed completely, the tumor reappears, or the surgery is considered too risky to perform, radiation therapy or medications might be recommended instead. Radiation therapy is typically administered through stereotactic radiosurgery, which uses targeted radiation beams to shrink the pituitary tumor and prevent further growth.

Medications such as somatostatin analogs (for example, octreotide, lanreotide), dopamine agonists (for example, cabergoline, bromocriptine), and growth hormone antagonists (including pegvisomant) can be used to reduce the growth hormone level or inhibit its effects.

If you suspect that you have acromegaly or have already been diagnosed with the condition, you should seek medical care from an endocrinologist. These specialists have expertise in hormonal disorders and the endocrine system (which includes the pituitary gland).

They can perform the necessary diagnostic tests, properly interpret the results, and provide treatment options tailored to your individual needs. When acromegaly is caused by a noncancerous pituitary gland tumor (pituitary adenoma), surgical intervention by a neurosurgeon may be necessary.

It is important to find an experienced neurosurgeon who can remove the pituitary tumor and minimize the risks involved with the procedure. Seeking a second opinion regarding the diagnosis and treatment of acromegaly can also be beneficial to ensure that proper steps are taken for your care.

• Diagnosis of acromegaly is typically made by performing a physical examination, taking a medical history, and ordering a blood test to measure growth hormone and IGF-1 levels
• Oral glucose tolerance and IGF-1 tests are the confirmatory tests for acromegaly diagnosis
• Magnetic resonance imaging and computed tomography studies can be used to locate and evaluate tumors causing excessive growth hormone production
• Acromegaly is commonly identified in middle-aged adults, usually between 30 and 50 years of age
• Early diagnosis and treatment of acromegaly are important for minimizing the risk of complications and improving long-term outcomes
• Treatment options for acromegaly include surgery, radiation therapy, medications or a combination of these approaches

• Pituitary Network Association: Acromegaly
• The Pituitary Foundation [UK]: Acromegaly
• National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK): Acromegaly
• National Health Service (NHS) [UK]: Acromegaly