Gigantism is a condition involving an overproduction of growth hormone (GH) before the age of puberty. Children and adolescents with this condition are atypically tall compared with children of the same age.

Gigantism is treatable, and treatments aim to manage pituitary tumor growth, control GH levels, and limit their effects on the body.

This article describes what gigantism is, including its causes and genetics, as well as its symptoms. It also outlines how doctors diagnose and treat gigantism and considers the outlook for those living with the condition.

Finally, it offers advice on when to contact a doctor and discusses whether gigantism is preventable.

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Gigantism is a condition in which an overproduction of growth hormone causes a child to grow atypically tall before reaching the age of puberty. Other names for the condition include pituitary gigantism and pediatric acromegaly.

Adults can experience a similar growth condition, which medical professionals refer to as “acromegaly.”

As a 2022 case study notes, gigantism is extremely rare, with only 3 or 4 children per million receiving a diagnosis each year.

According to a 2023 review, the most common cause of gigantism is a benign pituitary adenoma.

A benign pituitary adenoma is a noncancerous tumor on the pituitary gland, a small gland at the base of the brain that controls other glands in the body.

In gigantism, the benign pituitary adenoma causes the pituitary gland to secrete too much GH when the bones are still growing and have not yet fused.

Since bone fusion occurs at the end of puberty, a characteristic feature of gigantism is tall stature during childhood.


As a 2022 review notes, gigantism can run in families. Some genetic disorders that can cause gigantism include:

  • neurofibromatosis 1
  • McCune-Albright syndrome
  • multiple endocrine neoplasia type 1
  • Carney complex
  • 3PA association
  • isolated familial somatotropinomas
  • X-linked acrogigantism

The characteristic symptom of gigantism is atypically tall stature. This happens because the excess GH causes a child’s bones to grow rapidly and excessively before they have had a chance to fuse.

Other common signs and symptoms of gigantism include:

  • elevated levels of the following hormones in the blood:
    • the GH somatotropin
    • the GH insulin-like growth factor 1 (IGF1)
    • prolactin
  • advanced skeletal maturation, with bone scans indicating early bone maturation or advanced bone age
  • distinctive facial characteristics, such as:
    • an atypically prominent jaw and forehead
    • enlargement of the nose, lips, and tongue
    • gaps between the teeth
  • atypically large hands and feet
  • excessive sweating
  • enlargement of the heart and associated cardiomyopathy
  • enlargement of other organs
  • premature growth of pubic hair
  • absent periods

If a doctor suspects gigantism, they may refer the child to an endocrinologist, which is a doctor who specializes in hormonal conditions. The endocrinologist will assess the child’s symptoms and medical history and conduct a physical exam.

The endocrinologist may also order certain tests to help confirm a diagnosis of gigantism. These may include:

  • blood tests to check for high levels of GH, such as:
    • GH and IGF-1 tests
    • an oral glucose tolerance test (OGTT), which can detect a pituitary tumor
  • imaging tests to assess bone age or determine the location and size of a pituitary tumor, including:

Treatment for gigantism aims to:

  • manage pituitary tumor growth
  • address the effects of pituitary tumor growth on surrounding brain and nerve structures
  • control elevated levels of GH
  • address the systemic effects of excessive GH

Treatment options may include:

  • surgery to remove the pituitary tumor
  • radiation therapy to destroy tumor cells or prevent their growth
  • medications to control the production of GH or limit its effects on the body

The Children’s Hospital of Philadelphia states that children who receive early diagnosis and treatment for gigantism typically experience better outcomes and fewer complications.

However, individuals who receive multiple surgeries and multiple courses of radiotherapy to treat large pituitary adenomas often develop chronic pituitary hormone deficiencies.

As a 2023 review explains, outlook depends on the stage of the condition at diagnosis and the extent to which hormone levels respond to treatment.

Gigantism is usually the result of a benign pituitary adenoma, which is not a preventable disease.

However, children who carry a gene mutation that increases their risk of developing gigantism can undergo screening for excessive GH to help detect the condition early.

This will help the child to receive an earlier diagnosis and treatment, which can help reduce the risk of future complications.

Gigantism and acromegaly are conditions caused by the body producing too much GH. When this process occurs in preadolescence, doctors refer to it as gigantism. Doctors refer to it as acromegaly when it continues into adulthood or develops in adulthood.

As with gigantism, acromegaly usually results from a pituitary adenoma. More rarely, the cause may be a tumor in another part of the body that makes either GH or growth hormone-releasing hormone (GHRH). GHRH signals the pituitary gland to produce GH.

Examples include:

  • the hypothalamus, a part of the brain that sits near the pituitary gland
  • the pancreas
  • the lungs
  • other parts of the chest or abdomen

Acromegaly is treatable in most people, although the slow progression of the disease can lead to complications before a person receives a diagnosis and treatment. Potential complications include:

A parent or caregiver may wish to contact a doctor if their child has an atypically tall stature compared with other children of their age group or if the child is showing other potential signs of gigantism.

A doctor can run any necessary tests to confirm or rule out the diagnosis.

Gigantism is a condition involving an overproduction of growth hormone before an individual reaches the age of puberty. The most common cause is a type of noncancerous pituitary tumor.

Without prompt and appropriate treatment, gigantism can lead to complications, such as enlargement of the heart and associated disorders of the heart muscle. The condition may also continue into adulthood, at which point doctors will refer to it as “acromegaly.” This can cause complications, such as hypertension, heart disease, and type 2 diabetes.

The treatment for gigantism may consist of surgery to remove a benign pituitary adenoma and possibly medications to control the production of GH or limit its effects on the body. Treatment helps reduce the risk of serious complications.