Acromegaly is an uncommon condition due to excessive growth hormone (GH) produced by the pituitary gland. It affects adults after fusion of the growth plates of the long bones. The increased presence of GH stimulates a liver derivative called insulin-like growth factor 1 (IGF-1), which causes enlargement of tissue and organs.

Acromegaly is characterized by enlarged feet, hands, and face as well as ears, lips, tongue, nose, skin, and internal organs. The most common cause of acromegaly is a benign pituitary adenoma. This can arise sporadically, through genetic mutation, or in familial association with multiple endocrine neoplasia type 1, McCune-Albright syndrome, and Carney complex.

Gigantism, on the contrary, is found in children with hyperpituitarism prior to completing ossification of the growth plates. Its onset is rapid and quickly recognized due to the growth of long bones and conspicuously enlarging stature.

Acromegaly can progress slowly over a period of years to decades, going unrecognized until multiple organ complications become evident at the average age of 40. Among these serious complications are hypertension, cardiovascular disorders, type 2 diabetes, and arthritis.

The common signs and symptoms of acromegaly include enlarged hands and feet. Especially prominent are changed facial features (widening spaces between teeth, enlarging lips, jaw, brow, tongue, and nose) and skin overgrowth (thickened skin). Headaches, profuse sweating, and sleep apnea are common.

The effects caused by excessive GH include a wide array of clinical findings.

• Skin and soft tissue changes can include oily, course skin, enlarged pores, acrochordons (skin tags), hyperpigmentation, doughy skin with deepened forehead creases, and thickened nails and eyelids.
• Cardiovascular effects include hypertension, cardiomyopathy, arrhythmias, left ventricular hypertrophy, and other cerebrovascular and respiratory events.
• Joint and bone effects can include joint aches or pain, limited joint mobility, and progress to arthritis.
• Enlarged organs may include the thyroid, spleen, kidneys, liver, colon, and heart. Patients may be likely to develop recurring colonic polyps.
• Metabolism and other hormones can be affected. Pituitary dysfunction can cause imbalance in glucose and lipid metabolism. Other hormonal symptoms include excessive sweating (apocrine and eccrine) and body odor, interruption of the menstrual cycle, virilization, hirsutism, breast discharge in women, erectile dysfunction in men, and decreased libido. The presence of hypercalciuria, urolithiasis, and hyperphosphatemia also affect bone metabolism.
• Enlarged vocal cords and sinuses cause voice deepening and can contribute to airway obstruction during sleep, including onset of heavy snoring.

Since acromegaly is usually diagnosed late in its course, morbidity and mortality can remain high, especially due to irreversible cardiovascular, respiratory, rheumatologic, or metabolic effects. The prognosis is good for a typical life expectancy in patients diagnosed and treated early and receiving adequate hormonal control, depending on the extent of organ damage caused by the GH-stimulating adenoma and complications due to overgrowth.