Comparing Gigantism and Acromegaly: Their Distinct Features and Overlaps
Gigantism and Acromegaly are unusual growth disorders that stem from an excess of growth hormone (GH) in the body. These conditions are typically caused by a benign pituitary gland tumor, known as an adenoma, which accounts for over 95% of cases.
Causes
In most cases, both conditions result from a benign pituitary gland tumor (adenoma) that produces excess GH. However, in rare instances, excess GH can come from other neuroendocrine tumors or ectopic secretion of growth hormone-releasing hormone (GHRH).
Differences in Occurrence
Gigantism occurs when excess GH is secreted before the closure of the epiphyseal growth plates in children, leading to excessive linear growth and extreme height. On the other hand, Acromegaly develops in adults after the growth plates close, causing enlargement of bones and soft tissues rather than height increase.
Typical Symptoms
Acromegaly Symptoms
Acromegaly symptoms develop gradually, often with a late onset. Some common signs include:
- Enlarged hands and feet (e.g., outgrowing shoes and gloves)
- Enlarged nose, broad jaw, and tongue
- Coarsened facial features (prominent brow, large nose)
- Joint pain and swelling
- Fatigue and muscle weakness
- Deepening of the voice
- Excessive sweating and body odor
- Headaches and vision problems (due to tumor compression)
- Menstrual irregularities in women; erectile dysfunction in men
- Thickened skin
- Breathing difficulties, snoring
Acromegaly can also lead to several complications, such as type 2 diabetes, hypertension, heart disease, arthritis, colon polyps, and possible breathing difficulties.
Gigantism Symptoms
Gigantism symptoms primarily manifest as abnormally tall stature due to excessive long bone growth during childhood (before epiphyseal plate closure). In severe cases, it can also cause enlarged organs, similar to those seen in severe acromegaly affecting organs such as the heart and lungs.
Diagnosis
Doctors diagnose these disorders through a combination of clinical signs and specialized tests. Blood tests, such as those measuring insulin-like growth factor 1 (IGF-1) levels and GH levels following a glucose tolerance test, are crucial. Imaging tests, including MRI scans and X-rays, are also used to detect pituitary adenomas and assess bone enlargement and degenerative changes.
Treatment
Treatment aims to normalize GH levels, reduce tumor size, and manage symptoms. Surgery, medication, and radiation therapy are common treatment methods. Surgery, such as transsphenoidal resection, is often the first-line treatment if feasible. Medications like somatostatin analogs, dopamine agonists, and growth hormone-receptor antagonists can help control GH levels. Radiation therapy may be recommended if surgery is not possible or when surgery cannot remove all the tumor tissue.
In adults, excessive growth hormone over long periods can result in acromegaly, causing hand and foot swelling and altered facial features. Gigantism and acromegaly can be linked with several conditions, including neurofibromatosis, Carney complex, McCune-Albright syndrome, multiple endocrine neoplasia type 1 or type 4, and GPR101 gene mutation. Genetic syndromes such as multiple endocrine neoplasia type 1, familial isolated pituitary adenoma, and Carney complex can contribute to acromegaly.
Acromegaly affects approximately 50-70 people out of 1 million, while gigantism affects approximately 100 reported cases in the United States. It is essential to seek medical attention promptly if you suspect either of these conditions, as early diagnosis and treatment can significantly improve outcomes.
- Apart from pituitary gland tumors, other autoimmune disorders or neuroendocrine tumors may also cause an excess of growth hormone in the body.
- The immunesystem plays a crucial role in regulating the growth of tissues and organs, but when disrupted, it can lead to chronic diseases like gigantism and acromegaly.
- Endocrinology, the study of hormones, is instrumental in understanding and treating growth disorders such as gigantism and acromegaly, as well as their complications like type 2 diabetes, hypertension, heart disease, and other mental-health issues.
- Health-and-wellness management for people with gigantism and acromegaly should consider not only physical growth and complications but also neurological-disorders such as visual problems, sleep apnea, and psychological well-being.
