Special thanks to: 

Writer: Vladimir Novakovic, Research Associate, RareShare

Reviewer: John Wass, MD, Department of Endocrinology of Carol Davila University of Medicine and Pharmacy

The prevalence of the condition worldwide it is thought to be 1-9/100,000⁶ individuals⁷. Males and females are affected equally⁴.

Acromegaly is caused by benign - non-cancerous - tumours in the pituitary gland¹ -in the base of the skull³ - called adenomas. In very few individuals, it is caused by tumours of the pancreas, lungs, or other parts of the brain¹ because these organs can release growth hormone release hormone - commonly abbreviated to GHRH - which stimulates growth hormone – commonly abbreviated to GH⁷ – production in the pituitary gland³. Most tumours usually form from a genetic mutation in one a single, pituitary cell called a somatotrope cell (the pituitary cell that normally secretes GH). This mutation causes uncontrolled growth and reproduction of these cells. The tumours - if they are in the pituitary gland - secrete high levels of growth hormones (GH).

If Acromegaly occurs in puberty, the individual may experience giantism⁵. The symptoms appear gradually, and as the individual ages it is likely that the symptoms will become more pronounced. In most individuals, Acromegaly results in gradual enlargement of facial bones (as well as soft tissues and cartilage in the face), tongue, lips, hands, feet and cartilage (in other parts of the body) which can lead to joint pain. People with acromegaly may also develop a deep and husky voice due to thickening of the vocal cords and enlargement of the sinuses. Acrochordon (skin tags), hypertrichosis (excessive hair growth), hyperpigmentation (when an area of skin becomes darker than the surrounding skin, and is usually harmless) and hyperhidrosis (excessive sweating) are not uncommon³.

The overgrowth of tissue can lead to damaged nerves, causing carpal tunnel syndrome. In severe individuals it has lead to enlargement of the heart, causing irregular heartbeat and possibly congestive heart failure. Several conditions can be caused by Acromegaly, such as sleep apnea, high blood pressure, impaired vision or blindness, diabetes, and colon cancer. Males may experience decreased libido, and females may experience galactorrhea - abnormal milk flow from the breasts - and oligomenorrhea - infrequent or delayed menstrual flow.³ 

It is easy to overlook Acromegaly, as the symptoms develop slowly over a long period of time³. To make a diagnosis it is necessary to make a detailed history of an individual’s symptom history. Otherwise specialised tests can be used, such as blood tests, a glucose tolerance test, magnetic resonance imaging (MRI) or computerized tomography (CT) scan. Additional tests may be performed to assess the extent of acromegaly in an individual including echocardiography to evaluate whether the heart is involved³.

Patients with Acromegaly may be at increased risk for bone fractures, and testing with X-rays or assessment of bone mineral density with a DXA (Dual X-ray absorptiometry) scan may be ordered³. If Acromegaly is left diagnosed it can lead to disfigurement, or premature death⁵.

If acromegaly is suspect, it can be tested for through blood tests and glucose tolerance tests. The size of the tumour is also assessed and this can be via magnetic resonance imaging (MRI) or a computerized tomography (CT) scan, a CT however, may not show enough to confirm acromegaly. To determine the clinical impact of the disorder, x-rays and dual x-ray absorptiometry may be done, to measure increased risk of bone fracture. Patients may also undergo echocardiography and sleep apnea testing³.

Additional tests include an oral glucose tolerance test - a OGTT - or by detecting increased levels of an insulin like growth factor - IGF-I. Examining the tumours properties, such as volume, may be helpful⁴.

Treatment is aimed at correcting (or preventing) tumour compression by excising the disease-causing lesion, and at reducing GH levels to normal values⁵. Acromegaly is usually treated by transsphenoidal surgery; a procedure in which all or part of a pituitary tumour is removed.³ For patients where surgery is not possible or was not curative, medication can be used to treat acromegaly. Octreotide, pasireotide, lanreotide, cabergoline⁷, and pegvisomant may be prescribed¹. These medications are known as orphan drugs, because they affect a small percentage of the population¹. In individuals where medical treatment fails, radiotherapy may be discussed as third line treatment⁴.

If the disease is detected early enough, adequate hormonal disease control is achieved for most individuals, and allows a life expectancy similar to that of the general population⁵. However, if it is left undiagnosed and untreated, then premature death, or disfigurement may occur⁵.

There are many support organisations/groups that can offer support to individuals dealing with the diseases, or their caregivers. An especially recommended resource is http://www.pituitary.org.uk/ ⁷

1 Acromegaly. Genetics Home Reference. Available at: https://rarediseases.info.nih.gov/gard/5725/acromegaly/resources/1

2 Pituitary Adenoma 2, Growth-Hormone Secreting. Online Mendelian Inheritance in Man (OMIM). Available at: http://omim.org/entry/300943?search=Acromegaly&highlight=acromegaly

3 Acromegaly. The National Organization for Rare Disorders. Available at: http://rarediseases.org/rare-diseases/acromegaly/

4 Acromegaly. OrphaNet. Available at: http://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=EN&Expert=963

5 Acromegaly. Wikipedia. Available at: https://en.wikipedia.org/wiki/Acromegaly

6 Acromegaly. Malacards. Available at: http://www.malacards.org/card/acromegaly?search=+ACROMEGALY

7 Dr. John Wass