Acromegaly

What is acromegaly?

Acromegaly refers to a pronounced enlargement of the extremities and outwardly protruding body parts such as the nose, ears and chin. There can also be numerous other symptoms, such as changes to bones and joints, cardiovascular problems, misaligned teeth, speech disorders and difficulty swallowing and breathing due to an enlarged tongue.

These symptoms develop gradually. Those affected often don’t even notice them at first. As a result, acromegaly often exists for several years before a doctor diagnoses it for the first time.

Acromegaly is almost always caused by a benign tumor of the pituitary gland. “Benign” means that the tumor does not form metastases. What happens, however: The pituitary gland enlarges and the number of its hormone-producing cells increases. As a result, the pituitary gland produces too much growth hormone. This leads to the effects mentioned above, which can often be very stressful for those affected, not only physically but also psychologically. Acromegaly is not fatal. However, the symptoms it causes are often numerous and can become life-threatening if left untreated.

Children and adolescents can also develop acromegaly. In this case, the pituitary gland releases the excess growth hormone before the body has finished growing. The result is pathological gigantism, also known as hormonal gigantism. The person concerned becomes taller than average (often over two meters), but the body proportions remain largely unchanged.

Acromegaly – frequency and age

Acromegaly is a rare disease. In Switzerland, around 400 to 600 people are affected. Every year there are around 30 to 40 new cases. They are often between 40 and 50 years old, but children can also be affected.

Acromegaly: causes and risk factors

In most cases, acromegaly is caused by a benign tumor (adenoma) of the pituitary gland (hypophysis). It is extremely rare for other causes to trigger acromegaly, such as a neuroendocrine tumor of the lung or pancreas or a genetic mutation that leads to an excess of growth hormone production. There are also familial forms in which there is a genetic predisposition to the development of pituitary adenomas.

The pituitary gland is about the size of a cherry stone. It is located in the middle of the head, on the lower side of the brain, approximately at eye level or slightly above. The pituitary gland is the body’s hormone center. In addition to various other hormones, it releases the human growth hormone somatotropin (also known as somatotropic hormone or human growth hormone, HGH for short, or growth hormone, GH for short).

Stimulated by this hormone, the liver produces a messenger substance known internationally as “insulin-like growth factor 1” (IGF-1 for short). This growth factor has a tissue-building effect and plays a decisive role in cell growth.

If the pituitary gland is affected by a tumor, it may be affected by genetic changes that lead to an overproduction of growth hormone. This is how the various, often numerous and troublesome symptoms of acromegaly gradually develop.

Symptoms: Acromegaly

If you have acromegaly as an adult, you may initially only notice that your shoes no longer fit or that a ring has become too small for you. You may not even have considered that these could be signs of illness.

The symptoms of acromegaly do not appear suddenly, but develop slowly. So gradual that you hardly notice the external changes to the body. If you notice the changes, you may have already become accustomed to them and not consider them to be a cause for concern until other symptoms that cause discomfort are added at some point.

It is therefore not uncommon for those affected to seek medical advice until several years after the onset of acromegaly. At least some of the symptoms of this disease are actually quite recognizable. These are the signs of acromegaly:

• Hands and feet get bigger over time.
• The chin protrudes, the facial features become coarser.
• The nose, ears, eyes and lips enlarge.
• The edges of the eye sockets are bulging.
• The skin becomes thicker and there is an increased tendency to sweat (also known as hyperhidrosis). Increased hair growth may occur in women (so-called hirsutism)
• An enlarged tongue or changes in the palate lead to sleep problems (e.g. snoring, interrupted breathing).
• An enlarged lower jaw changes the position of the teeth and can cause problems when chewing.
• An enlarged heart can lead to leaky heart valves. High blood pressure is also possible.
• Internal organs (heart, liver, prostate, pancreas) can become enlarged.
• The spine can become deformed.
• Rheumatism-like pain can develop in joints and muscles.
• If the tumor of the pituitary gland presses on the optic nerve, visual disturbances can occur.
• Fat metabolism and blood sugar levels can be disturbed. Diabetes (diabetes mellitus) may develop.
• Growth processes in the hand, for example swelling of tendons, can lead to disturbances in blood circulation and nerve function. Carpal tunnel syndrome often manifests itself as an annoying tingling sensation or the hand falling asleep. At an advanced stage, the pain can extend far into the arm and the hand becomes weaker.

These symptoms do not necessarily all occur in acromegaly. And they rarely all appear at the same time.

Acromegaly: Diagnosis at the USZ

If we suspect that you have acromegaly, we will first ask you about your medical history and examine you. Subsequent blood tests in the laboratory are crucial for the correct diagnosis of acromegaly.

• The amount of growth hormone (GH) in your blood can indicate whether you have acromegaly. The normal fluctuations in the hormone concentration make it difficult to interpret the test result. The pituitary gland does not release the growth hormone evenly into the blood, but in spurts. This is why the hormone concentration fluctuates greatly, even in healthy people.
• An IGF-1 test provides a more reliable result. If the IGF-1 level in your blood is significantly elevated, this is an indication of acromegaly. However, the blood test alone is not sufficient for an acromegaly diagnosis. The IGF-1 concentration can also increase for other reasons (e.g. liver or kidney disease, taking medication).
• The glucose tolerance test or glucose suppression test is intended to indirectly clarify whether you have acromegaly. For this test, we ask you to drink a sugar solution (water and glucose). If you are healthy, sugar intake suppresses GH production. However, if you suffer from acromegaly, this mechanism does not work and the concentration of growth hormone in your blood remains high.

The blood tests serve to confirm an initial suspicion. However, further methods are necessary for a reliable diagnosis of acromegaly.

Diagnosis of pituitary tumor with MRI

If a blood test has confirmed your suspicion of acromegaly, we want to confirm the diagnosis. We would also like to know how large the suspected tumor of the pituitary gland is and in which directions it has spread. To clarify this, you will be given a magnetic resonance imaging (MRI) scan. Unlike X-rays or a computer tomography (CT) scan, they are not exposed to X-rays in an MRI.

Further examinations for acromegaly

Depending on which symptoms of acromegaly you experience and which accompanying symptoms we want to clarify, further examinations may follow. For example, clarifications of the heart and eyes. In addition, it must be checked whether the pituitary gland (hypophysis) affected by a benign tumor (adenoma) can still perform all its functions. As the control center of the hormonal system, the pituitary gland also regulates the production of other hormones. They are released, for example, by the thyroid gland or the adrenal glands.

Acromegaly: prevention, early detection, prognosis

As the symptoms of acromegaly only appear gradually, they are often overlooked for a long time. But even if they are recognized, such as enlarged feet (recognizable by a new shoe size), they are often not interpreted as a sign of progressive acromegaly.

It is therefore important that you always inform your doctor of any clear health complaints at an early stage. For example, numbness or pain in the wrist. In this case, we would consider that you may be suffering from so-called carpal tunnel syndrome. This weakening of the hand often occurs in the early stages of acromegaly. If carpal tunnel syndrome is recognized early, acromegaly can also be diagnosed and treated at an early stage.

Early diagnosis simplifies treatment and leads to a better course of the disease. However, there are no preventive measures.

Course and prognosis of acromegaly

There are two fundamentally different forms of acromegaly: The disease progresses differently in children and adolescents than in adults. The reason for this is that children and adolescents are still growing, whereas length growth is completed after the end of puberty. Acromegaly is triggered by an excess of growth hormone, regardless of age. However, the effect of the hormone is not the same at every age.

In children and adolescents, the ends of the bones, the so-called growth plates, have not yet closed. As long as the joints are not ossified, the growth hormone released by the pituitary gland in excessive quantities usually only causes an above-average increase in height. In adults, on the other hand, the growth plates have long since closed and longitudinal growth of the body is no longer possible. This is why the forces triggered by the growth hormone are now directed against bones, cartilage, soft tissue and internal organs. These increase in size, which can lead to numerous complaints.

The course of your acromegaly depends above all on when your disease is recognized and treated. It often takes more than five years from the appearance of the first symptoms to the diagnosis of acromegaly, sometimes even ten years or more.

The average life expectancy of people with acromegaly is lower than that of healthy people. This is due to the numerous burdens that this disease brings with it – for example, by damaging the heart or causing diabetes mellitus. However, if your acromegaly is not detected early and treated with modern therapy methods, you can live significantly longer with this disease than statistical averages would suggest.

Acromegaly: effective treatment

The best way to stop the progression of acromegaly is usually to remove the pituitary tumor that is causing it. If you suffer from such a (usually benign) tumor, we will most likely recommend that you have the pituitary tumor removed in hospital by surgery. Today, the tumor is generally accessed gently through the nose (transsphenoidal approach). In this way, the tumor can be reached from below and removed.

In a certain proportion of affected individuals, a residual tumor remains that cannot be removed by surgery and may retain a noticeable overproduction of growth hormone for patients. In these individuals, medication and/or radiotherapy can be used to suppress hormone overproduction and prevent further residual tumor growth (depending on the treatment). Which is the best option and when it should be used is determined individually in interdisciplinary discussions.