Overview Of Acromegaly
Acromegaly is a disorder that results from the person’s body making too much human growth hormone (HGH). Normally produced in the pituitary gland, HGH functions to control the growth rate of the body. The bones, organs, cartilage, and other tissues sometimes inappropriately increase in size when adults over-produce this hormone. Common symptomatic changes in appearance can include swollen or enlarged ears, hands, nose, or feet.
Commonly Associated With
Growth hormone excess, Growth hormone-secreting pituitary adenoma, Somatotroph adenoma, and Pituitary giant (occurs during childhood)
Causes Of Acromegaly
Acromegaly occurs when the pituitary gland over-produces and then releases too much HGH into the person’s body over an extended period of time. HGH alone does not actually cause the changes in bones and tissues, however. Another hormone produced in the liver, insulin-like growth factor I (IGH-I), is what actually causes the bones and body tissues to increase in size. The presence of HGH in the blood signals the body to create this hormone.
High levels of IGH-I can also affect how the person’s body processes glucose (sugar) and lipids (fats), which can lead to type 2 diabetes, heart disease, and high blood pressure in some people.
In more than 90% of cases, a tumor located in or near the pituitary gland causes acromegaly. A pituitary adenoma is another name for this type of tumor. In rare cases, the cause of the acromegaly could be a tumor located somewhere else in the body.
It is not yet known why these pituitary tumors develop, but it’s thought by many that genetic factors could possibly play a role in their development. In young adults, some specific gene defects have been directly linked to the development of acromegaly.
Symptoms Of Acromegaly
Acromegaly symptoms can vary from patient to patient, but some common features occur frequently.
Commonly seen changes in physical appearance due to acromegaly can include:
- The appearance of skin tags, which are small, flesh-colored skin growths that have a raised surface. They may also get darker or larger with time
- Changes to the skin, with it becoming coarser, thicker, and oilier
- A deepening of the voice
- Increased size of the nose, lips, and tongue
- Swelling and increased size of the hands and feet. They may notice a change in shoe or ring size, and especially shoe width
- Changes to the bones, including an increased size of the bridge of the nose, increased jutting out of the brow and lower jaw, and an increased space between the teeth
- An increase in sweating and skin odor
Other common symptoms can include
- joint aches
- vision problems
Treatments can include:
- Surgery – In some cases, health care providers can surgically remove the pituitary tumor to treat acromegaly. The surgeon will make a small incision in the nose area to remove the tumor. If the tumor can be completely removed, the person’s growth hormone levels will return to normal within hours, and their acromegaly symptoms can resolve completely over the course of a few months.
- Medications – Some patients with acromegaly need to take various medications as part of their treatment plan. They may need medication if they have a pituitary tumor that is inoperable for some reason, such as if the tumor is too large to remove completely. There are 3 types of medications health care providers can use to treat acromegaly:
1) Injections that work to prevent the tumor from releasing hormones, which can stop the progression of acromegaly. Some injections need to be taken 3 times a day, and others only once every 4 weeks. It depends on the specific brand that is prescribed and how it works.
2) Pills can be used to treat acromegaly – they stop the pituitary tumor causing the acromegaly from releasing any more hormones. Pills don’t tend to be quite as effective as injections, but they may be easier for patients to tolerate.
3) Medication that blocks the effects of growth hormone, so that no matter how much the pituitary releases, the acromegaly won’t progress. This treatment is taken once daily as an injection.
- Radiation can be used in some cases to treat acromegaly. Using high doses of X-rays, pituitary tumors can be destroyed, which would eliminate the source of the acromegaly.
All of these treatment options can have side effects. A health care provider will decide which treatment is best for each individual patient.
Often associated with acromegaly, pituitary tumors are almost always benign (noncancerous). Some of these tumors may grow quite slowly, and the symptoms of acromegaly may not actually be noticeable for many years. Other tumors could grow very quickly.
The tumor could press directly against the pituitary itself, depending on its location and size.
Possible effects of this type of tumor can include:
- Thyroid hormone changes, which can affect energy levels, weight, hair, and skin
- Erectile dysfunction
- Changes to menstruation
- Decreases in cortisol within the body, which can cause dizziness, weight loss, low blood pressure, fatigue, and nausea
Large tumors can also press against nearby parts of the brain besides the pituitary. This can lead to other additional symptoms, such as vision problems and headaches.
Some pituitary tumors can increase the levels of other hormones in the body, not just HGH. For example, some tumors produce prolactin, which is the hormone responsible for prompting the mammary glands to produce milk. This can lead to a breast milk discharge in some people.
In rare cases, acromegaly can be caused by tumors located in the hypothalamus, which is a small area of the brain located near the pituitary. In other cases, the tumors causing the acromegaly can be located outside the brain area, and can instead be located in the lungs, pancreas, or other parts of the abdomen or chest. Some of these non-pituitary tumors can produce their own HGH, but more often they produce growth hormone-releasing hormone (GHRH), which prompts the pituitary gland to make HGH.