Acromegaly is a syndrome that results when the pituitary gland produces excess growth hormone (hGH) after epiphyseal plate closure. Acromegaly most commonly affects adults in middle age and can result in severe disfigurement, serious complicating conditions, and premature death if unchecked.

Acromegaly is often also associated with gigantism.

Symptoms

• Soft tissue swelling visibly resulting in enlargement of the hands, feet, nose, lips and ears, and a general thickening of the skin
• Soft tissue swelling of internal organs, notably the heart with attendant weakening of its muscularity, and the kidneys, also the vocal cords resulting in a characteristic thick, deep voice and slowing of speech
• Generalized expansion of the skull at the fontanelle
• Pronounced brow protrusion, often with ocular distension
• Pronounced lower jaw protrusion with attendant macroglossia (enlargement of the tongue) and teeth gapping
• Hypertrichosis, hyperpigmentation, and hyperhidrosis may occur in these patients

Other symptoms

• Abnormalities of the menstrual cycle and sometimes breast discharge in women
• Erectile dysfunction in men
• Decreased libido

Causes

• In over 90 percent of acromegaly patients, the overproduction of growth hormones is caused by a benign tumor of the pituitary gland, called an adenoma.
• These tumors produce excess growth hormones and, as they expand, compress surrounding brain tissues, such as the optic nerves.
  
• This expansion causes the headaches and visual disturbances that often accompany acromegaly.
• In some cases its tumor of pancreas, adrenal gland, and lungs.
• These tumors also lead to an excess of GH, either because they produce GH themselves or, more frequently, because they produce GHRH (Growth Hormone Releasing Hormone), the hormone that stimulates the pituitary to make GH.

Complications

• Severe headache 
  
• Arthritis and carpal tunnel syndrome
  
• Enlarged heart
  
• Hypertension
  
• Diabetes mellitus
  
• Heart failure
  
• Kidney failure
  
• Compression of the optic chiasm leading to loss of vision in the outer visual fields (typically bitemporal hemianopia)
  Increased palmar sweating and sebum production over the face (seborrhea)
  

Tests and diagnosis

• IGF1 provides the most sensitive and useful lab test for the diagnosis of acromegaly. A single value of the Growth hormone (GH) is not useful in view of its pulsatality (levels in the blood vary greatly even in healthy individuals).
• GH levels taken 2 hours after a 75 or 100 gram glucose tolerance test are helpful in the diagnosis: GH levels are suppressed below 1 μg/L in normal people, and levels higher than this cutoff are confirmatory of acromegaly.
• Other pituitary hormones have to be assessed  include TSH (thyroid stimulating hormone), gonadotropic hormones (FSH,LH), ACTH (adrenocorticotropic hormone), prolactin.
• An MRI of the brain gives a clear delineation of the pituitary and the hypothalamus and the location of the tumor.

Treatment

Currently, treatment options include surgical removal of the tumor, medical therapy, and radiation therapy of the pituitary.

Goals of treatment are to

• Reduce excess hormone production to normal levels
• Relieve the pressure that the growing pituitary tumor may be exerting on the surrounding brain areas
• Preserve normal pituitary function or treat hormone deficiencies
• Improve the symptoms of acromegaly

Surgery

• Surgery is the first option recommended for most people with acromegaly, as it is often a rapid and effective treatment.
• If the surgery is successful, facial appearance and soft tissue swelling improve within a few days.
• Surgery is most successful in patients with blood GH levels below 45 ng/ml before the operation and with pituitary tumors no larger than 10 millimeters (mm) in diameter.
  

Medical Therapy

Medical therapy is most often used if surgery does not result in a cure and sometimes to shrink large tumors before surgery.

Two medication groups are used to treat acromegaly.

• Somatostatin analogs (SSAs) are the first medication group used to treat acromegaly. They shut off GH production and are effective in lowering GH and IGF-I levels in 50 to 70 percent of patients. SSAs also reduce tumor size in around 0 to 50 percent of patients but only to a modest degree.
• Dopamine agonists make up the third medication group. These drugs are not as effective as the other medications at lowering GH or IGF-I levels, and they normalize IGF-I levels in only a minority of patients.

Radiation therapy

• Radiation therapy is usually reserved for people who have some tumor remaining after surgery and do not respond to medications.
• Because radiation leads to a slow lowering of GH and IGF-I levels, these patients often also receive medication to lower hormone levels.
• The full effect of this therapy may not occur for many years.

Patient education

• Remission depends on the initial size of the tumor, the GH level, and the skill of the neurosurgeon.
• Remission rates of 80-85% and 50-65% can be expected for micro adenomas and macro adenomas, respectively.
• The postoperative GH concentration may predict remission rates.