What is Cushing's Disease?
Cushing disease
Cushing disease is a condition in which the pituitary gland releases too much adrenocorticotropic hormone (ACTH). The pituitary gland is an organ of the endocrine system.
Cushing disease is a form of Cushing syndrome.
Causes
Cushing disease is caused by a tumor or excess growth (hyperplasia) of the pituitary gland. The pituitary gland is located at the base of the brain. A type of pituitary tumor called an adenoma is the most common cause. An adenoma is almost always benign (not a cancer).
With Cushing disease, the pituitary gland releases too much ACTH. ACTH stimulates production and release of cortisol, a stress hormone. Too much ACTH causes the adrenal glands to make too much cortisol.
Cortisol is normally released during stressful situations. It controls the body's use ofcarbohydrates, fats, and proteins and also helps reduce the immune system's response to swelling (inflammation).
Symptoms
Symptoms of Cushing disease include:
Upper body obesity (above the waist) and thin arms and legs
Round, red, full face (moon face)
Slow growth rate in children
Skin changes that are often seen include:
Acne or skin infections
Purple marks (1/2 inch or more wide), called striae, on the skin of the abdomen, thighs, and breasts
Thin skin with easy bruising, most commonly on the arms and hands
Muscle and bone changes include:
Backache, which occurs with routine activities
Bone pain or tenderness
Collection of fat between the shoulders (buffalo hump)
Thinning of the bones, which leads to rib and spine fractures
Weak muscles
Women often have:
Excess hair growth on the face, neck, chest, abdomen, and thighs
Menstrual cycle that becomes irregular or stops
Men may have:
Decreased or no desire for sex
Impotence
Other symptoms may include:
Mental changes, such as depression, anxiety, or changes in behavior
Fatigue
Headache
Increased thirst and urination
Exams and Tests
Tests are done to confirm there is too much cortisol in the body, then to determine the cause.
These tests confirm too much cortisol:
24-hour urine cortisol
Dexamethasone suppression test (low dose)
Salivary cortisol levels (early morning and late at night)
These tests determine cause:
Blood ACTH level
Brain MRI
Corticotropin-releasing hormone test, which acts on the pituitary gland to cause the release of ACTH
Dexamethasone suppression test (high dose)
Inferior petrosal sinus sampling (IPSS) - measures ACTH levels in the veins that drain the pituitary gland compared to the veins in the chest
Other tests that may be done include any of the following:
Fasting blood glucose and hemoglobin A1c to test for diabetes
Lipid and cholesterol testing
Bone mineral density scan to check for osteoporosis
Treatment
Treatment involves surgery to remove the pituitary tumor, if possible. After surgery, the pituitary gland may slowly start to work again and return to normal.
During the recovery process, you may need cortisol replacement treatments. Radiation treatment of the pituitary gland may also be used if the tumor is not completely removed.
If the tumor does not respond to surgery or radiation, you may need medicines to stop your body from making cortisol.
If these treatments are not successful, the adrenal glands may need to be removed to stop the high levels of cortisol from being produced.
Outlook (Prognosis)
Untreated, Cushing disease can cause severe illness, even death. Removal of the tumor may lead to full recovery, but the tumor can grow back.
Possible Complications
Compression fractures
Diabetes
High blood pressure
Infections
Kidney stones
Mental illness
When to Contact a Medical Professional
Call your health care provider if you develop symptoms of Cushing disease.
If you have had a pituitary tumor removed, call if you have signs of complications, including signs that the tumor has returned.
Alternative Names
Pituitary Cushing disease