Acromegaly is a rare metabolic disorder that causes over-growth of limbs. Acromegaly means about as much as "enlargement of the outermost parts of the body". Those affected have very large ears, nose, hands and feet. The cause is a brain tumor that leads to an overproduction of a growth hormone. Acromegaly can be inherited through gene mutations. In rare cases, it also occurs as part of inheritable syndromes. Acromegaly is not curable. However, there are drug and surgical options to alleviate the disease.
What are the symptoms of acromegaly?
A typical symptom of acromegaly is that sufferers have thickened, wrinkled skin and coarsened facial features with a large nose and ears. The eyelashes emerge, hands and feet ("acres") are greatly enlarged ("-mega").
The development of the symptoms is creeping for years. Classically, those affected notice that shoes, rings and hats are no longer suitable.
The internal organs - especially heart and spleen - take on a dangerous size. The tongue also grows and the teeth diverge, which can lead to a "dumpling" language (as if you had a hot potato in your mouth) and nocturnal breathing problems (sleep apnea syndrome).
Arterial hypertension and visual disturbances as signs
Other signs of acromegaly include high blood pressure (arterial hypertension) and headache. If the brain tumor is already so large that it presses on the visual pathway, visual disturbances and visual field limitations occur.
Tissue growth on the hands can narrow the median nerve of the forearm, resulting in the so-called "Carpal Tunnel Syndrome" with nocturnal pain of the first three fingers and sensory disturbances.
Metabolic disorders are typical in acromegaly
Other typical complaints include increased hair growth (hypertrichosis) and sweating (hyperhidrosis). The external genitalia can also be enlarged. Some patients develop a sugar metabolism disorder (diabetes mellitus).
In female patients, the menstrual cycle remains (amenorrhea). In male patients there is again a reduced sex drive and impotence.
How does acromegaly develop?
The cause of acromegaly is in 95 percent of cases, a pituitary adenoma, so a benign brain tumor. The pituitary gland, also called pituitary gland, is a gland located in the midbrain and produces, among other things, the growth hormone somatotropin ("GH = growth hormone"). This hormone promotes growth in childhood and plays an important role in fat, carbohydrate and protein metabolism.
Forms a tumor of the pituitary gland first increases the release of hormones and it comes in adult age to a continued growth of the hands, feet, facial and internal organs.
If adolescents are affected who have not yet completed their length growth, the result is gigantism, a sub-form of acromegaly with a body height of more than two meters. However, the most common cases are patients between the ages of 40 and 50 years.
Rare causes of acromegaly
In rare cases, the cause of acromegaly is a malignant pituitary tumor or a tumor elsewhere in the brain that produces growth hormone in large quantities.
In even more rare cases, the disease occurs in the context of Erberkankungen, for example, in the lipodystrophy type Berardinelli.
How does the doctor diagnose acromegaly?
An average of five to ten years elapse from the onset of the illness until the diagnosis develops, as the symptoms develop slowly. Often the environment does not notice the slow change of the affected person's body, only in direct comparison with old photos is the difference recognizable. Only when other symptoms appear, the patient seek a doctor.
The specialist in diagnosis and treatment of acromegaly is an endocrinologist, ie a metabolism expert.
Blood tests and imaging in the context of diagnostics
If suspected acromegaly disease, the doctor first examines the blood. The production of the disease-causing growth hormone depends on the time of day, which is why several blood samples have to be taken in one day.
Another study tests the regulability of growth hormone release by the administration of sugar (oral glucose tolerance test, oGTT). In a healthy patient, it should come after the consumption of pure sugar (glucose) to a drop in growth hormone in the blood in diseased persons, the hormone levels remain high.
If the suspicion of an acromegalic disease becomes evident as a result of the blood tests, imaging must be performed to visualize the tumor in the brain. For this purpose, either a magnetic resonance tomography (MRI) or a computed tomography (CT) is initiated.
How to treat acromegaly
The cause of acromegaly is the pituitary tumor. This can sometimes be surgically removed if it is not too big. The surgery can usually be done through the nose, this procedure is called "transsphenoidal adenomectomy".
Another possibility is to irradiate the tumor in order to reduce it and reduce its activity.
Complicating the removal of the tumor can lead to complete pituitary dysfunction, requiring the drug hormones it replaces to be replaced.
Alternative therapies for acromegaly
If the first two methods are unsuccessful or can not be used at all, the drug therapy will remain. This hormones are distributed, which counteract the growth hormone somatotropin and thus to reduce the progression of symptoms.
Medications used for this purpose are (exemplary drug in parentheses):
- Dopamine preparations (bromocriptine)
- Somatostatin preparations (octreotide)
- GH receptor antagonist (Pegvisomant)
Untreated, life expectancy is shortened by about ten years. The cause of death is the impairment of the heart, vessels and brain by the disease. In addition, acromegaly patients are more likely to suffer from breast and colon cancer.