Cushings' Syndrome
Cushings' syndrome is an uncommon syndrome that happens when your body has too much of a hormone called cortisol. It is also called hypercortisolism. Cortisol is a steroid hormone commonly called the stress hormone.
Causes
Use of glucocorticoid medications.
Glucocorticoid medications (for example, prednisone) are used to treat many autoimmune diseases, for example chronic asthma, rheumatoid arthritis, lupus, sarcoidosis and many other diseases that result in chronic inflammation. Chronic treatment with these medications causes iatrogenic Cushing’s syndrome. Iatrogenic refers to something that is caused by a medical treatment.
Pituitary tumors.
Pituitary tumors that make too much ACTH (the hormone that tells the adrenal glands to make cortisol) cause eight out of 10 cases of Cushing’s syndrome (excluding the cases of iatrogenic Cushing’s syndrome). This is called Cushing’s disease.
Adrenal cortical tumors.
A tumor on the adrenal gland itself can make too much cortisol. These are usually benign.
Lung, pancreas, thyroid and thymus tumors.
Tumors that develop outside of the pituitary gland can produce ACTH and this is called ectopic ACTH syndrome. These types of tumors are typically malignant. The most common type of these tumors is small cell lung cancer.
Symptoms
A red, round face.
Wounds that heal poorly.
High blood pressure (hypertension).
Excessive hair growth on the face, neck, chest, abdomen, breasts and thighs, or balding.
Diabetes.
Purple stretch marks over the abdomen.
Easy bruising on the arms and legs.
General weakness and tiredness (fatigue).
Blurry vision and dizziness.
Weak muscles and thinner arms and legs.
Libido changes (sex drive) and erectile dysfunction.
Stunted growth in children.
Diagnosis
24-hour urinary cortisol test
This test measures the amount of cortisol in micrograms in your urine. Your healthcare provider will have you collect your urine over a period of 24 hours. 50-100 micrograms per day is a lot and could mean Cushing’s syndrome.
Midnight salivary cortisol test
Cortisol levels are known to be very low in the morning, and also low late at night. This test checks cortisol levels between 11:00pm and 12:00am. If you have Cushing’s syndrome, your cortisol levels will be unusually high during that hour.
Low-dose dexamethasone suppression test
Dexamethasone is a cortisol-like drug.
In this test, one milligram of the drug taken orally at night and then the cortisol levels are measured the following morning.
This test determines whether or not the adrenal glands responded to the dexamethasone by suppressing the amount of cortisol they secrete.
If you have Cushing’s syndrome, your adrenal glands will not be suppressed, which means your cortisol levels the following morning will remain high. Cortisol levels are known to be very low in the morning.
If you don’t have Cushing’s syndrome, you’ll have low levels of cortisol in the morning.
If the levels are high, that means you likely have Cushing’s syndrome.
Blood test
A blood test will measure the ACTH levels in your blood. An adrenal tumor might be there if the levels are low. If the levels are normal or high, there could be a pituitary or ectopic tumor.
High-dose dexamethasone suppression test
This test is like the low-dose dexamethasone suppression test, but the dosage is eight milligrams instead of one.
This test is typically performed after the low dose test shows high levels of cortisol in the morning (i.e. failure to suppress), and when blood tests show high ACTH in the blood.
This test is used to determine the source of Cushing’s, specifically to differentiate between a pituitary adenoma (Cushing’s disease) and a tumor elsewhere in your body
Cat scan (CT scan) or MRI abdomen
A CT scan or MRI may be performed to look for a tumor in your adrenal glands. These scans can be done with or without IV contrast. They are very sensitive at identifying adrenal tumors.
Magnetic resonance imaging (MRI) pituitary
An MRI will take a picture of your pituitary gland to see if there’s a tumor. In some cases, the MRI will not provide a perfect diagnosis. 50% of those with Cushing’s syndrome will have a “normal” MRI and 10% will have tumors unrelated to the syndrome.
Treatment
Chemotherapy
Chemotherapy is necessary if a tumor is cancerous and has spread to other parts of your body. Be sure to discuss all side effects with your healthcare provider.
Medications
Adding drugs that reduce cortisol or taking away drugs that can cause Cushing’s syndrome.
Radiation
Surgery on a pituitary tumor may not be possible. In those cases, you might have to go through a six-week period of radiation. Cortisol levels may take years to return to normal. Medicines that increase cortisol levels are available. Be sure to discuss all side effects with your healthcare provider.
Surgery
Surgically removing pituitary tumors, adrenal tumors and ectopic tumors is effective, but you’ll have to be prescribed cortisol medicine. You’ll be able to stop the medications after six to 18 months. Often, after laparoscopic surgery, you’ll be able to leave the hospital within one or two days and feel back to normal in about three to five weeks.