Acromegaly is a chronic, debilitating, slowly progressive multisystem disorder caused by excessive secretion of growth hormone (GH). In the majority of cases, acromegaly results from benign pituitary adenomas; a benign tumor formed from glandular structures in epithelial tissue. In rare cases, acromegaly is caused by ectopic production of growth-hormone-releasing hormones (Patel, Ezzat and Chik). The effects of acromegaly can be quite obvious. Andre the Giant may be one of the most famous examples of acromegaly that not many equate to the disease. “At 7'4" and 500 pounds, Andre the Giant could have been famous for his size alone. His drive, talent and ambition, however, proved to be as big as Andre himself, and the…show more content…
“The epiphyseal plates have closed normally, preventing any further elongation of long bones, but all of the bones become more massive through appositional bone growth” (Roiger); growth in the bone diameter. This is very noticeable in bones of the face as the patient matures through adulthood. “Acromegaly is most often diagnosed in middle-aged adults, although symptoms can appear at any age” (Services).
Normal secretion of growth hormone is regulated by the hypothalamus. Normally, growth hormone from the hypothalamus is transported to the anterior pituitary gland where it is released. GH released from the anterior pituitary binds to and activates specific cells (Roiger). Growth hormone is released in a pulsatile manner and acts on the liver, bone, cartilage, muscle, and adipose tissue to stimulate the production of insulin-like growth factor-I (IGF-I). Circulating IGF-I in the body is derived mainly from the liver and feeds back on the anterior pituitary and hypothalamus to inhibit further growth hormone secretion (Patel, Ezzat and Chik).
In the case of acromegaly, growth hormone is produced independently by a pituitary tumor and results in sustained hyper-secretion of both growth hormone and IGF-I, which causes the majority of the clinical manifestations. The elevated growth hormone levels are generally proportional to tumor size (Patel, Ezzat and Chik).
When benign pituitary tumors cause acromegaly, the tumors are thought to be