Cushing's disease, also called ACTH-producing pituitary tumor, is a pituitary tumor that secretes adrenocorticotrophin hormone (ACTH) and causes overproduction of cortisol by the adrenal glands.
Excessive cortisol production causes:
- Weight gain, particularly in the abdomen and neck
- Loss of muscle
- Sleep disturbance
- Memory loss
- Difficulty concentrating
- Loss of sexual function
- Loss of menstrual periods
- Thin skin, easy bruising and red stretch marks, usually on the abdomen
- High blood pressure
- Diabetes mellitus
- Osteoporosis and bone fractures
- Abnormal lipids (cholesterol)
- Heart disease
- Kidney stones
Diagnosing Cushing's Disease
Cushing's disease is the most difficult diagnosis of all pituitary disorders.
The diagnosis requires two separate stages:
- The first stage establishes if you're producing cortisol
- The second stage determines the precise cause of this excess cortisol production
A multidisciplinary approach involving endocrinologists and neurosurgeons is essential for the correct diagnosis and appropriate management of patients with Cushing’s disease.
Screening for Excess Cortisol Production
There are three screening tests that detect excess and abnormal cortisol production:
- 24-hour urine-free cortisol levels
- Late-night salivary cortisol levels
- Blood cortisol response to 1 mg of dexamethasone at 11 p.m. combined with a blood cortisol at 8 a.m. the next day (overnight low dose dexamethasone test).
Since these tests aren't 100 percent accurate, several tests are often needed to confirm a diagnosis. These include:
- Measurement of serum ACTH levels
- Blood cortisol response to 8 mg of dexamethasone at 11 p.m. (overnight low dose dexamethasone test) combined with a blood cortisol at 8 a.m. the next day
- CRH stimulation test
- Inferior petrosal sinus sampling (requires hospitalization and a procedure by a specialist)
- CT or MRI scans
Treatment for Cushing's Disease
Surgery is the best treatment is removal of the tumor.
Medication is used to control adrenal gland cortisol overproduction, but does not treat the source of the problem, the pituitary tumor. Careful monitoring is necessary to establish the optimal dose and to determine if it's effective and has no unwanted effects on the liver.
If surgery does not work, we can use irradiation to return cortisol production to normal and control tumor growth. This works in 50-60 percent of patients.
Gamma Knife radiosurgery is another option. It provides a precisely targeted, single dose of radiation, in comparison to conventional irradiation therapy, which takes five weeks of daily treatment.
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Content was created using EBSCO’s Health Library. Edits to original content made by Rector and Visitors of the University of Virginia. This information is not a substitute for professional medical advice.