Gigantism: Causes, Symptoms, and Treatment for Excessive Growth

What is gigantism?

Gigantism is a rare medical condition characterised by excessive growth caused by an overproduction of growth hormone (GH) during childhood, specifically before the fusion of the long bone epiphyses (growth plates). This results in abnormally tall stature, as well as enlargement of muscles and internal organs. Individuals with gigantism often experience significant height increases, sometimes exceeding 7 feet.

One of the most common gigantism causes is usually a benign tumour on the pituitary gland, known as a pituitary adenoma, which stimulates the excessive secretion of growth hormone. Other potential gigantism causes can include genetic mutations that affect hormone regulation. Early gigantism symptoms or signs may include an increase in shoe and hand size, noticeable changes in facial features (such as enlarged jaws), and joint pain due to the rapid growth of bones and tissues.

Diagnosis typically involves a thorough medical history, physical examination, and blood tests to measure hormone levels. Imaging tests like MRI scans may be conducted to identify any pituitary tumours. Gigantism treatment often includes surgical removal of the tumour, if present, and medication to regulate hormone levels.

Early intervention is crucial in managing the condition and mitigating potential complications, such as diabetes, hypertension, and cardiovascular issues. Regular monitoring and a comprehensive treatment plan can significantly improve outcomes for individuals with gigantism.

What is the difference between gigantism and acromegaly?

While both gigantism and acromegaly involve GH hypersecretion, the key difference lies in when the excess GH production occurs:

• Gigantism happens when GH hypersecretion occurs before the fusion of the long bone epiphyses, usually during childhood or adolescence. This results in tall stature and proportional body growth.
• Acromegaly occurs when GH hypersecretion happens after the fusion of the epiphyses, typically in adulthood. This leads to deformed bones, coarse facial features, and enlarged extremities without increased height.

Who does gigantism affect?

Gigantism primarily affects children and adolescents before they reach full physical maturity. Studies show that it is more common in males, with about 78% of pituitary gigantism cases reported in boys.

How common is gigantism?

Gigantism is an extremely rare condition, even less common than acromegaly, which itself is rare. While the exact prevalence is not well-documented, it is estimated that pituitary gigantism affects about 8 to 11 people per million population.

How does growth normally happen in children?

Normal growth in children is a complex process regulated by several key factors.

• It begins when the pituitary gland releases growth hormone (GH) into the bloodstream. GH plays a crucial role in stimulating the liver to produce insulin-like growth factor-1 (IGF-1), which is vital for growth and development. IGF-1 then promotes the growth of bones, muscles, and other tissues throughout the body.
• Additionally, growth plates, known as epiphyseal plates, located at the ends of long bones, are essential for increasing height. These growth plates allow for the elongation of bones until they gradually fuse during late adolescence, marking the end of height increase.
• Several factors influence this growth process, including genetics, nutrition, physical activity, and overall health. Adequate nutrition, particularly sufficient intake of proteins, vitamins, and minerals, is crucial for supporting growth.
• Regular physical activity also promotes healthy growth and development in children, helping them achieve their full growth potential.

What are the symptoms of gigantism?

Children with gigantism may exhibit several distinct symptoms that indicate an underlying hormonal imbalance. Some common gigantism symptoms include:

• Excessive linear growth and tall stature
• Enlarged hands and feet
• Thickened facial features (frontal bossing, broad nasal bridge, protruding jaw)
• Widely spaced teeth
• Frequent headaches
• Increased sweating
• Joint pain
• Delayed puberty
• Sleep problems, such as sleep apnea
• Voice changes
• Muscle weakness
• Galactorrhea (release of breast milk)
• Menstrual irregularities in girls
• Vision issues

If you notice your child experiencing an unusual growth spurt along with any of these gigantism symptoms, it’s important to consult your doctor. Early intervention can lead to appropriate diagnosis and management, improving your child's health outcomes. Recognising gigantism symptoms promptly can make a significant difference in treatment options.

What causes gigantism?

The most common gigantism causes is a noncancerous pituitary tumour known as a somatotropinoma, which secretes excess growth hormone. This overproduction of growth hormone leads to accelerated growth and development, causing the characteristic symptoms of gigantism.

Other possible gigantism causes include various genetic diseases that can disrupt normal hormone regulation and promote excessive growth. Some of these genetic disorders are:

• Carney complex: A rare syndrome that can cause multiple tumours and hormonal imbalances
• McCune-Albright syndrome: A condition that affects bone, skin, and hormone production, leading to various abnormalities.
• Multiple endocrine neoplasia type 1 (MEN-1): A genetic disorder that results in tumours in multiple endocrine glands.
• Neurofibromatosis type 1: A genetic disorder characterised by the growth of noncancerous tumours on nerves, which can affect hormone levels.
• Isolated familial somatotropinomas: A hereditary condition where family members may experience growth hormone-secreting tumours.
• X-linked acrogigantism: A rare genetic condition linked to excessive growth hormone production.

In some cases, gigantism may be idiopathic, meaning the exact cause is unknown. This makes it essential for healthcare providers to conduct thorough evaluations to determine the underlying factors contributing to gigantism. Identifying these gigantism causes can aid in developing effective treatment plans to manage the condition or possible gigantism complications.

How is gigantism diagnosed?

Gigantism is diagnosed through a combination of methods aimed at assessing growth patterns and hormonal imbalances.

• The process begins with a clinical evaluation, which includes a thorough physical exam and medical history to identify symptoms like excessive growth and facial changes.
• Laboratory tests measure elevated levels of insulin-like growth factor 1 (IGF-1) and conduct growth hormone (GH) suppression tests to confirm GH hypersecretion.
• Additionally, healthcare providers assess prolactin, cortisol, estradiol (in girls), testosterone (in boys), and thyroid hormone levels.
• Imaging studies, such as CT or MRI scans, are also utilised to detect any pituitary tumours responsible for the condition.

What tests will be done to diagnose gigantism?
 

To diagnose gigantism, healthcare providers typically recommend a series of tests to evaluate hormone levels and identify potential underlying causes.

• Blood tests are essential in this diagnostic process. These include measuring growth hormone (GH) and insulin-like growth factor 1 (IGF-1) levels, as elevated levels indicate hypersecretion.
• Additionally, testing for other pituitary hormones such as adrenocorticotropic hormone (ACTH), thyroid-stimulating hormone (TSH), luteinizing hormone (LH), follicle-stimulating hormone (FSH), and prolactin is crucial for a comprehensive evaluation.
• Cortisol and thyroid function tests are also performed to assess overall hormonal balance, along with measuring testosterone in boys or estradiol in girls.
• An oral glucose tolerance test (OGTT) may be conducted to further confirm GH hypersecretion, as GH levels should typically decrease after glucose intake.
• In addition to blood tests, imaging studies such as an MRI of the pituitary gland are crucial for detecting any tumours, while CT scans of the chest and abdomen may be utilised to rule out ectopic GH secretion.

How is gigantism treated?

Gigantism treatment aims to reduce GH levels and manage complications. The main treatment options include:

Surgery for Gigantism

Surgery is the preferred treatment for most cases of gigantism caused by a pituitary tumour. The goal is to remove or reduce the tumour to decrease GH production. This is usually done through transsphenoidal surgery, where the tumour is accessed through the nose and sinus cavity. However, because gigantism is often diagnosed late, the tumours may be large, and surgery alone may not be curative. Additional treatments like radiation or medication may be needed.

Radiation Therapy for Gigantism

Gigantism treatment may include radiation therapy if surgery cannot completely remove the tumour or if GH levels remain high post-surgery. Radiation beams are targeted at the remaining tumour tissue to lower GH over time. The effects can take several years.

Medications can also help manage gigantism when surgery is not an option or as an adjunct therapy. Drugs like octreotide and lanreotide can suppress GH secretion, while bromocriptine and cabergoline can reduce GH levels. However, their effectiveness in children is not as well-studied as in adults with acromegaly.

What are the complications of gigantism treatment?

Gigantism treatment can lead to certain complications that may affect the patient's overall health and well-being.

• One of the most common issues is hypopituitarism, which occurs in approximately 60% of treated patients, resulting in a deficiency of one or more pituitary hormones and often requiring lifelong hormone replacement therapy.
• Other potential gigantism complications include adrenal insufficiency, characterised by inadequate adrenal hormone production, and diabetes insipidus, a rare condition marked by extreme thirst and excessive urination.
• Additionally, patients may experience hypogonadism, which involves reduced production of sex hormones, and hypothyroidism, leading to low levels of thyroid hormones.

Can gigantism be prevented?

Gigantism cannot be prevented as it is caused by tumours or genetic conditions. Early detection through regular check-ups and prompt treatment are key to managing the condition and preventing complications.

What is the outlook for gigantism?

The outlook for individuals with gigantism can be quite favourable with timely and effective treatment. Many of the changes caused by excess growth hormone (GH) can be reversed, leading to significant improvements in overall prognosis. However, long-term effects on bones, joints, and the heart are common and may require ongoing management.

Pituitary surgery is often successful in significantly reducing GH levels, yet regular monitoring is essential to address any residual or new symptoms that may arise. With appropriate treatment and management, life expectancy can be normal.

Overall, with the right approach, individuals with gigantism can lead healthy and fulfilling lives, though vigilance is key to managing potential health issues effectively.

What are the complications of gigantism?

Some potential gigantism complications include various health issues that can significantly impact quality of life. These may include:

• Cardiovascular problems, such as an enlarged heart and an increased risk of heart failure, can be serious.
• Vision loss may occur due to compression of the optic nerves.
• Patients often experience joint pain and arthritis, along with enlarged organs affecting overall function.
• Individuals may suffer from headaches, weakness, and nerve compression symptoms.
• Physical changes, such as coarsened facial features, large hands and feet, thickened skin, and excessive sweating, can also be prevalent, leading to both physical discomfort and psychological distress.

When to see a doctor?

Parents should consult a doctor if they notice signs of abnormal growth in their child, such as:

• Growing much faster than peers
• Very large hands and feet
• Coarsening of facial features
• Headaches or vision problems
• Joint pain
• Excessive sweating

Early diagnosis allows for timely treatment to manage symptoms and prevent complications.

Conclusion

Gigantism is a rare but serious condition that requires prompt medical attention. If you suspect your child might have gigantism symptoms, don't hesitate to consult a doctor. Early treatment is crucial to manage the condition and ensure the best possible outcomes.

At Metropolis Healthcare, we understand the importance of accurate diagnosis for managing conditions like gigantism. Our team of expert technicians offers convenient at-home sample collection for growth hormone and other essential tests. With our state-of-the-art labs and commitment to quality, you can trust us for reliable results to guide your treatment decisions. Book your tests today and take the first step towards a healthier future.