The document defines gigantism as abnormally large growth due to excess growth hormone during childhood, before growth plates close. It describes the pathophysiology of gigantism as being caused by overproduction of growth hormone from a pituitary adenoma, which leads to increased insulin-like growth factor 1 (IGF-1) levels. The clinical features of gigantism include excessive growth, delayed puberty, headaches, and enlarged hands and feet. Diagnostic tests include CT/MRI scans showing a pituitary adenoma, and high levels of growth hormone and IGF-1. Treatment involves surgery to remove the adenoma, radiation therapy, and drug therapy such as bromocriptine.

1. (A Project of National Medical Centre Karachi)
(GIGANTISM )
Shahzad Bashir.
Lecturer, NMC ION

2. OBJECTIVES:
• By the end of this lecture, the students will
be able to:
• Define Gigantism
• Describe the pathophysiology of gigantism
• List the clinical features
• Elaborate the diagnostic criteria
• Discuss the medical management
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3. GIGANTISM
DEFINITION:
Overproduction of growth hormone causes
excessive growth. In children, the condition is
called gigantism. In adults, it is called acromegaly.
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4. GIGANTISM
DEFINITION:
Gigantism is an abnormally large growth due to
excess growth hormone during childhood,
before growth plates close.
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8. GIGANTISM
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9. Hypothalamus
PATHOPHYSIOLOGY
(GHRH)
Anterior
Somatotrophs
pituitary
KEY:
Growth-promoting actions Anti-insulin effects 1. IGF-1(Insulin like
Growth hormone Growth Factor -1.
2. FFA, Free Fatty
Acid
Liver
IGF-1
Adipose Carbohydrate
tissue metabolism
Increased protein synthesis
Decreased
Bone and Body Increased lipolysis
Muscle glucose use
cartilage organs Increased FFA use
Decrease in Increased blood
Increased Increased Increased glucose
adiposity
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size lean muscle 4/11/2013
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growth function mass

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11. CAUSES
Raised level of GH from pituitary adenoma
OTHER FACTORS:
Hypoglycemia
Fasting
Starvation
Increased blood levels of amino acids (particularly arginine)
Stress conditions such as trauma
Excitement,
Emotional stress, and
Heavy exercise.
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12. CLINICAL FEATURES
Excessive growth.
The child is large for their age.
Delayed puberty.
Double vision or difficulty with peripheral vision.
Headaches.
Increased sweating.
Large hands and feet.
Thickening of facial features.
Weakness.
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13. INVESTIGATIONS
CT scan
MRI
GH raised level
IGF-1 raised level
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14. TREATMENT
SURGERY:
Transphenoidal surgery to remove the pituitary
adenoma.
Radiation therapy.
Drug therapy.
Bromocriptine
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16. REFERENCES
Porth, M. C. (2009). Pathophysiology Concepts of
altered health states (7th ed.). Lippincott Williams &
Wilkins.
Tortora, G. J. & Grabowski, S.R. (2000). Principles of
anatomy and physiology (12th ed.). New York: John
Wiley & sons Inc.
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