Ectopic Cushing syndrome
Ectopic Cushing syndrome is a form of Cushing syndrome in which a tumor outside the pituitary gland produces a hormone called adrenocorticotropic hormone (ACTH).
Cushing syndrome - ectopic; Ectopic ACTH syndrome
Cushing syndrome is a disorder that occurs when your body has a higher than normal level of the hormone cortisol. This hormone is made in the adrenal glands. Too much cortisol can be due to various problems. One such problem is called Cushing disease. It occurs when the pituitary gland makes too much of the hormone ACTH. ACTH then signals the adrenal glands to produce too much cortisol. This is much more common than ectopic Cushing syndrome.
Ectopic Cushing syndrome, on the other hand, occurs when ACTH is produced somewhere other than the pituitary gland. Ectopic means occurring in an abnormal place.
Ectopic Cushing syndrome is caused by tumors that release ACTH. Tumors that can, in rare cases, release ACTH include:
- Benign carcinoid tumors of the lung
- Islet cell tumors of the pancreas
- Medullary carcinoma of the thyroid
- Small cell tumors of the lung
- Tumors of the thymus gland
Ectopic Cushing syndrome tends to have fewer symptoms than classic Cushing syndrome. Most people with any type of Cushing syndrome have:
- Round, red, and full face (moon face)
- Slow growth rate in children
- Weight gain with fat accumulation on the trunk, but fat loss from the arms, legs, and buttocks (central obesity)
Skin changes that are often seen:
- Skin infections
- Purple stretch marks (1/2 inch 1 centimeter or more wide) called striae on the skin of the abdomen, thighs, upper arms, and breasts
- Thin skin with easy bruising
Muscle and bone changes include:
- Backache, which occurs with routine activities
- Bone pain or tenderness
- Collection of fat between the shoulders and above the collar bone
- Rib and spine fractures caused by thinning of the bones
- Weak muscles, especially of the hips and shoulders
Body-wide (systemic) problems may include:
- Type 2 diabetes mellitus
- High blood pressure
- High cholesterol and triglycerides
Women may have:
- Excess hair growth on the face, neck, chest, abdomen, and thighs
- Periods that become irregular or stop
Men may have:
- Decreased or no desire for sex
Other symptoms that may occur include:
- Mental changes, such as depression, anxiety, or changes in behavior
- Increased thirst and urination
Exams and Tests
The health care provider will perform a physical exam and ask about your symptoms.
Tests that may be done include:
- 24-hour urine sample to measure cortisol and creatinine levels
- Blood tests to check ACTH, cortisol, and potassium levels
- Dexamethasone suppression test (both high and low dose)
- Fasting glucose
- MRI and high resolution CT scans to find the tumor
The best treatment for ectopic Cushing syndrome is surgery to remove the tumor. Surgery is usually possible when the tumor is noncancerous (benign).
In some cases, the tumor is cancerous and spreads to other areas of the body before the doctor can discover the problem with cortisol production. Surgery may not be possible in these cases. But the doctor may prescribe medicines to block cortisol production.
Surgery to remove the tumor may lead to full recovery. But there is a chance that the tumor will come back.
The tumor may spread or return after surgery. A high cortisol level may continue.
When to Contact a Medical Professional
Call your provider if you develop symptoms of Cushing syndrome.
Prompt treatment of tumors may reduce the risk in some cases. Many cases are not preventable.
Nieman LK, Biller BM, Findling JW, et al. Treatment of Cushing's syndrome: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2015;100(8):2807-2831. PMID 26222757 www.ncbi.nlm.nih.gov/pubmed/26222757.
Stewart PM, Newell-Price JDC. The adrenal cortex. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, eds. Williams Textbook of Endocrinology. 13th ed. Philadelphia, PA: Elsevier; 2016:chap 15.