Cushing's syndrome is a rare hormonal problem. It happens when there is too much of the hormone cortisol in your body.
Normally, cortisol levels increase through a chain reaction of hormones:
- First, the hypothalamus in the brain makes a hormone called CRH (corticotropin-releasing hormone).
- Then, CRH tells the pituitary gland to make another hormone called ACTH (adrenocorticotropic hormone).
- ACTH then tells the adrenal glands to make cortisol. Cortisol affects almost every area of the body. It is especially important in regulating blood pressure and metabolism.
But if your body makes too much cortisol — or if you take certain medicines that act like cortisol — you may start to have symptoms. Cushing's syndrome may cause weight gain, skin changes, and fatigue. It can lead to serious problems, such as diabetes, high blood pressure, depression, and osteoporosis. If not treated, it can also cause death.
Another name for Cushing's syndrome is hypercortisolism.
Symptoms vary, but most people have upper body obesity, rounded face, increased fat around the neck and thinning arms and legs. Children tend to be obese with slowed growth rates.
Other symptoms appear in the skin, which becomes fragile and thin. It bruises easily and heals poorly. Purplish pink stretch marks may appear on the abdomen, thighs, buttocks, arms and breasts. The bones are weakened, and routine activities such as bending, lifting or rising from a chair may lead to backaches, rib and spinal column fractures.
Most people have severe fatigue, weak muscles, high blood pressure and high blood sugar. Irritability, anxiety and depression are common.
Women usually have excess hair growth on their faces, necks, chests, abdomens, and thighs. Their menstrual periods may become irregular or stop. Men have decreased fertility with diminished or absent desire for sex.
Weight gain—especially around the waist—is the most common symptom.
Cortisol affects almost all body systems, so it can cause many other symptoms.
These other symptoms often appear slowly over time and may include:
- Weak muscles.
- Changes in the skin, such as bruising, acne, and dark purple-red stretch marks on the belly.
- Changes in mood. You may feel irritable, anxious, or depressed.
- Extra fat on the back of the neck and upper back.
- Loss of muscle tone.
- Irregular menstrual periods.
- Hair growth that is not normal (such as facial hair in women).
- High blood pressure and high blood sugar levels.
Sometimes alcoholism, depression, panic attacks, obesity, or other problems can cause symptoms like these. Some treatments for HIV can also cause similar symptoms. This is called pseudo-Cushing's syndrome. In these cases, symptoms tend to stop as soon as the problems are treated.
Treatment depends on the specific reason for cortisol excess and may include surgery, radiation, chemotherapy or the use of cortisol-inhibiting drugs. If the cause is long-term use of glucocorticoid hormones to treat another disorder, the doctor will gradually reduce the dosage to the lowest dose adequate for control of that disorder. Once control is established, the daily dose of glucocorticoid hormones may be doubled and given on alternate days to lessen side effects.
Several therapies are available to treat the ACTH-secreting pituitary adenomas of Cushing's disease. The most widely used treatment is surgical removal of the tumor, known as transsphenoidal adenomectomy. Using a special microscope and very fine instruments, the surgeon approaches the pituitary gland through a nostril or an opening made below the upper lip. Because this is an extremely delicate procedure, patients are often referred to centers specializing in this type of surgery.
The success, or cure, rate of this procedure is over 80 percent when performed by a surgeon with extensive experience. If surgery fails, or only produces a temporary cure, surgery can be repeated, often with good results. After curative pituitary surgery, the production of ACTH drops two levels below normal. This is a natural, but temporary, drop in ACTH production, and patients are given a synthetic form of cortisol (such as hydrocortisone or prednisone). Most patients can stop this replacement therapy in less than a year.
For patients in whom transsphenoidal surgery has failed or who are not suitable candidates for surgery, radiotherapy is another possible treatment. Radiation to the pituitary gland is given over a 6-week period, with improvement occurring in 40 to 50 percent of adults and up to 80 percent of children. It may take several months or years before patients feel better from radiation treatment alone. However, the combination of radiation and the drug mitotane can help speed recovery.
Mitotane suppresses cortisol production and lowers plasma and urine hormone levels. Treatment with mitotane alone can be successful in 30 to 40 percent of patients. Other drugs used alone or in combination to control the production of excess cortisol are aminoglutethimide, metyrapone, trilostane and ketoconazole. Each has its own side effects that doctors consider when prescribing therapy for individual patients.
Ectopic ACTH Syndrome
To cure the overproduction of cortisol caused by ectopic ACTH syndrome, it is necessary to eliminate all of the cancerous tissue that is secreting ACTH. The choice of cancer treatment - surgery, radiotherapy, chemotherapy, immunotherapy, or a combination of these treatments - depends on the type of cancer and how far it has spread.
Since ACTH-secreting tumors (for example, small cell lung cancer) may be very small or widespread at the time of diagnosis, cortisol-inhibiting drugs, like mitotane, are an important part of treatment. In some cases, if pituitary surgery is not successful, surgical removal of the adrenal glands (bilateral adrenalectomy) may take the place of drug therapy.
Surgery is the mainstay of treatment for benign as well as cancerous tumors of the adrenal glands. In Primary Pigmented Micronodular Adrenal Disease and the familial Carney's complex, surgical removal of the adrenal glands is required.