What Is Gigantism?
Gigantism is a rare growth disorder that occurs in children and adolescents before the growth plates (epiphyses) close. It is characterized by excessive growth in height and size due to an overproduction of growth hormone (GH), usually caused by a noncancerous (benign) tumor in the pituitary gland called an adenoma.
If the same hormone imbalance occurs after the growth plates have closed, the condition is called acromegaly, not gigantism.
What Causes Gigantism?
The most common cause of gigantism is a pituitary adenoma, a benign tumor that increases growth hormone production. Other less common causes include:
- Genetic mutations (e.g., in the AIP gene)
- McCune-Albright syndrome
- Carney complex
- Neurofibromatosis
- Familial isolated pituitary adenomas (FIPA)
What Are the Symptoms of Gigantism?
The symptoms are usually noticeable in childhood or early adolescence and include:
- Abnormally rapid and excessive growth in height
- Enlarged hands, feet, and facial features
- Coarse facial features (prominent jaw, nose, or forehead)
- Delayed puberty
- Joint pain or limited mobility
- Excessive sweating
- Headaches and vision problems (if the tumor compresses nearby structures)
- Thickened skin
- Weakness or fatigue
What Are the Risks and Complications of Gigantism?
If left untreated, gigantism can lead to serious health issues, including:
- Diabetes mellitus
- High blood pressure (hypertension)
- Cardiovascular disease
- Sleep apnea
- Spinal deformities or joint damage
- Enlarged organs (organomegaly), such as the heart or liver
- Emotional or psychological challenges due to appearance or social difficulties
How Is Gigantism Diagnosed?
Diagnosis involves a combination of medical history, physical exams, and imaging tests:
- Blood tests: Elevated growth hormone (GH) and insulin-like growth factor 1 (IGF-1) levels
- Oral glucose tolerance test (OGTT): GH levels remain high even after drinking glucose
- MRI of the brain: To detect a pituitary tumor
- X-rays or bone age studies: To assess growth plate development
What Are the Treatment Options for Gigantism?
Treatment focuses on reducing GH levels and managing the tumor:
- Surgery (Transsphenoidal surgery): Removal of the pituitary adenoma, often the first-line treatment
- Medications:
- Somatostatin analogs (e.g., octreotide, lanreotide) to reduce GH secretion
- GH receptor antagonists (e.g., pegvisomant) to block GH effects
- Dopamine agonists (e.g., cabergoline) in some cases
- Radiation therapy: Used if surgery and medications are not fully effective
Can Gigantism Be Prevented?
There is no known way to prevent gigantism, especially if it’s caused by a genetic mutation. However:
- Early detection and treatment can prevent complications
- Genetic counseling may be helpful for families with a history of related conditions
How to Manage Gigantism for a Better Quality of Life?
For Children and Families:
- Ensure regular monitoring by an endocrinologist
- Stay on prescribed medications and attend follow-up appointments
- Consider physical therapy to manage joint or posture issues
- Offer emotional and psychological support, especially during adolescence
For Adults Diagnosed in Adolescence:
- Monitor for long-term effects like heart disease or diabetes
- Maintain a healthy lifestyle (diet, exercise, stress management)
- Seek support groups or therapy for coping with physical and social challenges