Cushing syndrome is an endocrine system disorder that has several possible causes. This article discusses Cushing syndrome caused by too much production of cortisol due to an adrenal gland tumor.

Cushing syndrome is caused by constant, high levels of cortisol, a stress hormone. The growth of a tumor on one of the two adrenal glands causes about 15% of all cases of Cushing syndrome. Adrenal tumors release cortisol.

Adrenal tumors may be benign (non-cancerous) or malignant (cancerous). Non-cancerous tumors that may cause Cushing syndrome include adrenal adenomas or micronodular hyperplasia. Adrenal carcinomas are cancerous tumors that may cause Cushing syndrome.

Adrenal tumors are rare. They may develop in anyone at any age, but are much more common in adults. They are found in women more often than men.

For other causes and information about Cushing syndrome see:

Cushing syndrome

Ectopic Cushing syndrome

Exogenous Cushing syndrome

See also:

Cushing's disease

• Moon face (round, red, and full)
• Weight gain
  • Buffalo hump (a collection of fat between the shoulders)
  • The weight gain has a particular pattern -- a protruding abdomen and thin extremities
• Skin changes
  • Thinning of the skin
  • Easy bruising
  • Acne or other skin infections
  • Purple streaks on the skin of the abdomen, thighs, and breasts
• High blood pressure
• Weakness (often noticed when trying to stand up or to raise hand above head)
• Backache
• Headache
• Thirst
• Increased urination
• Mental changes, including an exaggerated feeling of happiness (euphoria), not linked to a life event
• Stopping of menstruation in women
• Breast development and impotence in men

Patients with a cancerous adrenal tumor may also have symptoms of higher-than-normal androgen levels, including excessive hair in unusual parts of the body (in women), acne, and scalp hair loss.

Tests to confirm Cushing syndrome:

• 24-hour urine sample to measure the following:
  • Urine cortisol
  • Urine creatinine
• Dexamethasone suppression test
• Serum cortisol levels
• Saliva cortisol levels

Tests to determine cause:

• ACTH
• High-dose dexamethasone suppression test
• Abdominal CT (may show adrenal tumor)

Other findings may include:

• High fasting glucose
• Low serum potassium
• Low bone density, seen by dual x-ray absorptiometry (DEXA)
• High cholesterol