Editor - Pediatric Oncall
What is Cushing's syndrome?
Increase in blood cortisol levels in the body is called as Cushing's syndrome.
What are the causes of Cushing's syndrome?
Common causes that increase blood cortisol levels are pituitary tumors, adrenal tumors, McCune Albright syndrome. Sometimes excessive steroid intake in form of drugs can lead to increase blood cortisol levels.
Why do blood cortisol levels increase?
In case of pituitary tumors, ACTH hormone levels increase which in turn increases blood cortisol levels. Sometimes ACTH levels can rise in patients with Wilm's tumor, other types of cancer such as cancer of pancreas or kidneys. In case of tumors of adrenal glands (adrenal adenoma or carcinoma), the adrenals themselves produce more cortisol. Drugs that contain steroids (cortisol) can increase blood cortisol levels.
What are the symptoms of Cushing's syndrome?
Increased weight and obesity is one of the commonest presenting features of Cushing's syndrome. The children appear to get chubbier cheeks, more fat deposition of the back and chest. Striae and bruisability may be seen. Their height velocity starts falling. Fine vellous hair may appear over cheeks and forehead. Blood pressure may be elevated. Puberty is often delayed. The bones are often osteopenic.
What laboratory tests are needed to diagnose Cushing's syndrome?
The diagnosis of Cushing's syndrome is usually made clinically. However to differentiate between adrenal cause and pituitary cause, tests may be required. The most common screening test to establish increased serum cortisol levels is to do 24 hours urine estimation of free cortisol. Normally, the levels are between 20-70 µg/sqm, however in case of Cushing's syndrome, urinary free cortisol is elevated. To find out the cause, your doctor may do blood ACTH levels and high dose dexamethasone suppression test. In case of pituitary tumors, ACTH levels will be elevated. In case of adrenal tumors, ACTH levels will be decreased. High dose dexamethasone tests consists of given high dose dexamethasone 6 hourly for 48 hours and then doing urinary free cortisol on 2nd day. In case of suppression of secretion of cortisol in urine, it suggests a pituitary cause and in case of non suppression, it suggests adrenal cause.
Your doctor may advise CT/MRI of adrenals or pituitary gland to look for any tumor.
What is the treatment of Cushing's syndrome?
The treatment depends upon the cause. In case of Cushing's disease due to intake of drugs containing steroids, the same will have to be stopped.
In case of pituitary tumors, surgical removal is required. In case of adrenal tumor, surgical removal of offending adrenal gland is required. In case of ACTH being secreted from some other site of the body, then one may have to remove both adrenal glands and give life long maintenance steroids. Sometimes drugs such as ketoconazole that decrease blood cortisol levels are required. However this may be only required in those who are not cured of surgery or are waiting for surgery.
Last updated on 01-07-2010