Symptom Finder - Gigantism
GIGANTISM
The differential of this symptom can be developed physiologically by overactivity or underactivity of an endocrine gland. Thus, overactivity of the pituitary gland (as in eosinophilic adenomas of the pituitary) causes gigantism from too much growth hormone, whereas underactivity of the testicles (as in Klinefelter syndrome) produces a tall individual because the inadequate secretion of testosterone delays closure of the epiphysis.
Tumors of the adrenal cortex, testicle, and pineal gland may produce macrogenitosomia or prepubertal gigantism by stimulation of overgrowth by androgens and estrogens only to lead to ultimate dwarfism by premature closure of the epiphysis. Primary gigantism is like the gigantism of plants and flowers; genetic arachnodactyly is also a genetic form of gigantism, although it is a true disease and is associated with dislocation of the lens.
Approach to the Diagnosis
The approach to the diagnosis of these conditions is simple. Radioimmunoassay (RIA) studies of hormone levels are now readily available, and x-rays of the skull with CT scans and tomography will allow a diagnosis. Referral to an endocrinologist may be wise from the start, especially because potentially tall girls may want endocrine therapy to close the epiphysis early.
Other Useful Tests
1. Serum growth hormone (pituitary adenoma)
2. Serum corticotropin, luteinizing hormone (LH), and folliclestimulating
hormone (FSH) levels (pituitary adenoma)
3. Serum testosterone (Klinefelter syndrome, adrenal tumors, and
hyperplasia)
4. Serum dihydrotestosterone and dehydroepiandrosterone sulfate
(adrenal tumor and hyperplasia)
5. Urine hydroxyproline level (Marfan syndrome)
6. Urine homocysteine level (homocystinuria)
7. Chromosomal analysis (Klinefelter syndrome)
8. MRI of the pituitary (microadenoma)
9. Testicular biopsy (Klinefelter syndrome)
The differential of this symptom can be developed physiologically by overactivity or underactivity of an endocrine gland. Thus, overactivity of the pituitary gland (as in eosinophilic adenomas of the pituitary) causes gigantism from too much growth hormone, whereas underactivity of the testicles (as in Klinefelter syndrome) produces a tall individual because the inadequate secretion of testosterone delays closure of the epiphysis.
Tumors of the adrenal cortex, testicle, and pineal gland may produce macrogenitosomia or prepubertal gigantism by stimulation of overgrowth by androgens and estrogens only to lead to ultimate dwarfism by premature closure of the epiphysis. Primary gigantism is like the gigantism of plants and flowers; genetic arachnodactyly is also a genetic form of gigantism, although it is a true disease and is associated with dislocation of the lens.
Approach to the Diagnosis
The approach to the diagnosis of these conditions is simple. Radioimmunoassay (RIA) studies of hormone levels are now readily available, and x-rays of the skull with CT scans and tomography will allow a diagnosis. Referral to an endocrinologist may be wise from the start, especially because potentially tall girls may want endocrine therapy to close the epiphysis early.
Other Useful Tests
1. Serum growth hormone (pituitary adenoma)
2. Serum corticotropin, luteinizing hormone (LH), and folliclestimulating
hormone (FSH) levels (pituitary adenoma)
3. Serum testosterone (Klinefelter syndrome, adrenal tumors, and
hyperplasia)
4. Serum dihydrotestosterone and dehydroepiandrosterone sulfate
(adrenal tumor and hyperplasia)
5. Urine hydroxyproline level (Marfan syndrome)
6. Urine homocysteine level (homocystinuria)
7. Chromosomal analysis (Klinefelter syndrome)
8. MRI of the pituitary (microadenoma)
9. Testicular biopsy (Klinefelter syndrome)