Acromegaly – This Rare Disease Can Cause Giantism and Facial Distortion
If you are an old horror movie buff, you might recognize these lines from the 1944 film, The Monster Maker, starring J. Carroll Naish and Ralph Morgan. In the above dialogue, Ralph Morgan’s character, Anthony Lawrence, has just been told by his doctor, Dr. Adams, that he has acromegaly. Dr. Adams proceeds to try to explain this rare disease and its consequences to his patient.
In actuality, the definition recited above by Dr. Adams to his patient Anthony Lawrence is an accurate, if simplistic, description of acromegaly. While knowledge about this rare disease – rare diseases are diseases that affect fewer than 200,000 Americans – has increased since 1944, it remains a relatively obscure disorder; most patients do not receive an accurate diagnosis until the disease has progressed for several years. Indeed, acromegaly (once known as Marie Disease) is an insidious disorder caused by the over secretion of the growth hormone (GH) which is produced by the pituitary gland. The disease is characterized by abnormal enlargement of the extremities and head, particularly the facial bones and jaws; there is also thickening of soft tissues, including heart tissue.
The most common cause of hypersecretion of the growth hormone is a pituitary adenoma – a benign tumor – which affects the somatotrophic (another name for growth hormone) cells in the anterior lobe of the gland.
In children and adolescents, hypersecretion of the growth hormone produces a condition called giantism. This results due to the fact that the epiphyses – the end of the long bone and the shaft of the bone separated by cartilage – has not yet fused, ordinarily allowing normal growth. But, with the overabundance of GH the child becomes too tall, his hands and feet enlarged with the accompanying facial distortion. In adults, whose epiphyses have already fused, there is no increase in height, only the spade-like hands, over-sized feet and coarsening and thickening of frontal, facial bones.
A converse condition in children known as pituitary hypothyroidism may occur by the same invading adenoma or by necrosis. This condition, known as panhypopituitarism, prevents any secretion of hormones which may result in abnormalities of the thyroid and adrenal glands and the gonads (ovaries or testis.) It eventually leads to pituitary dwarfism. The treatment for this condition would be the administration of genetically engineered growth hormone produced by recombinant DNA technology. The poorly monitored administration of this synthetic GH sometimes, ironically, leads to excess levels, resulting in the condition of giantism (sometimes referred to as gigantism) in adolescents.
While acromegaly itself – acron=extremity; megas=large – is not necessarily a fatal disorder, many complications and/or conditions may arise from it and cause serious functional difficulties, especially if the disease goes untreated. The distention of the facial and jaw bones may lead to wide separations in the teeth; the voice frequently becomes hoarse and husky. Many of the vital organs, such as the spleen, kidneys, liver and heart may become enlarged. The enlargement of the heart may lead to congestive heart failure. Since overproduction of GH is antagonistic to the action of insulin, a good percentage of adults will develop increased blood glucose levels leading to diabetic conditions. There is often a darkening of the skin accompanied by hirsutism (abnormal growth of body hair.)
The body’s metabolic rate increases (leading to the fabulous and dangerous energy levels alluded to by Dr. Adams); there is also increased activity in the sweat and oil-producing (sebaceous) glands. Patients may experience spinal compression, resulting in severe pain; often osteoarthritis develops characterized by a loss of cartilage between the joints. As the disease progresses the patient may develop myopathy – muscular weakness – and neuropathy – abnormalities in the nerve endings; severe eye problems may ensue which sometimes lead to permanent blindness.
Standard treatment of acromegaly is surgical removal of the invading pituitary adenoma or partial or total removal of the pituitary gland. If the entire pituitary gland is removed, the patient is compelled to submit to lifelong hormone replacement therapy. GH suppressors, including estrogen, medroxyprogesterone and chlorpromazine have had limited success. Treatment of acromegaly with somatostatin analogue (Sandostatin), also a growth hormone suppressor, is now widely employed. This drug has been shown to increase surgical remission if it is administered preoperatively. It has also been shown to significantly decrease the size of pituitary adenomas; it is available in many medical centers throughout the country.
The key to successful treatment and management of acromegaly is early detection, before many of the debilitating conditions take hold of a patient’s health. This is somewhat easier said than done inasmuch as this rare disease still tends to remain undetected in many patients in early stages. Doctors who observe persistent symptoms in their patients should begin to suspect an endocrinologic cause; gaining a better understanding of the etiology and pathogenesis of endocrine disorders along with improved diagnostic techniques, and an increase in therapeutic options will help improve health care for the unique minority who are afflicted with diseases such as acromegaly.
