Ectopic Cushing syndrome

Also known as: Cushing syndrome - ectopic

Definition

Ectopic Cushing syndrome is a condition in which a tumor outside the pituitary or adrenal glands produces a hormone called adrenocorticotropic hormone (ACTH).

Causes, incidence, and risk factors

Cushing syndrome is the result of too much glucocorticoid hormones being released over a long period of time. About 15% of Cushing syndrome cases are due to ectopic Cushing syndrome.

Ectopic Cushing syndrome is caused by tumors that release adrenocorticotropic hormone (ACTH). Other causes of Cushing syndrome are:

• Excess release of ACTH by the pituitary gland
• Long-term use of corticosteroid drugs (commonly used to treat conditions such as rheumatoid arthritis and asthma)
• Tumor of the adrenal gland

Tumors that can, in rare cases, release ACTH include:

• Islet cell tumors of the pancreas
• Medullary carcinoma of the thyroid
• Small cell tumors of the lung
• Tumors of the thymus gland

Symptoms

Ectopic Cushing syndrome tends to have fewer dramatic symptoms than classic Cushing syndrome, but it can occur with higher blood pressure and a lower potassium level. Weight loss may occur due to cancer.

Symptoms of Cushing syndrome are:

• Abdomen sticks out; arms and legs are thin (central obesity)
• Acne or minor skin infections
• Buffalo hump
• Headache
• Impotence (in men)
• Increased urination
• Menstrual cycle stops (in women)
• Mental changes
• Purple stretch marks on the skin of the abdomen, thighs, and breasts
• Round, red, and full face (moon face)
• Tanning or darkening of the skin
• Thirst
• Weakness

Signs and tests

Tests that may be done include:

• 24-hour urine for cortisol and creatinine
• Blood tests to check ACTH, cortisol, and potassium levels
• Dexamethasone suppression test
• Fasting glucose
• MRI and CT scans to find tumors

Treatment

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 health care provider can discover the problem with cortisol production. Surgery may not be possible in these cases, but the doctor may prescribe drugs to block cortisol production.

Expectations (prognosis)

Surgery to remove the tumor may lead to full recovery, but there is a chance that the tumor will come back.

Complications

The tumor may spread or return after surgery. High cortisol levels may continue.

Calling your health care provider

Call your health care provider if you develop symptoms of Cushing syndrome.

Prevention

Prompt treatment of tumors may reduce the risk in some cases. Many cases are not preventable.

References

Arnaldi G, Angeli A, Atkinson AB, et al. Diagnosis and complications of Cushing's syndrome: A consensus statement. J Clin Endocrinol Metab. 2003;88:5595-5602.

Stewart PM. The adrenal cortex. In: Kronenberg HM, Melmed S, Polonsky KS, Larsen PR. Williams Textbook of Endocrinology. 11th ed. Philadelphia, PA: Saunders Elsevier; 2007:chap 14.

See also:

• Special Topic

  Adrenal glands

  

  Adrenal glands are triangle-shaped glands located on top of the kidneys. The outer part of the adrenal gland is called the cortex and produces steroid hormones such as , , and . The inner part of the adrenal gland is called the medulla and produces and , which are commonly called adrenaline and ...

• Disease

  Rheumatoid arthritis

  

  Rheumatoid arthritis (RA) is a long-term disease that leads to inflammation of the joints and surrounding tissues. It can also affect other organs.

• Disease

  Medullary carcinoma of thyroid

  

  Medullary carcinoma of the thyroid is cancer of the thyroid gland that starts in cells that release a hormone called calcitonin. Such cells are called “C” cells.

• Disease

  Tumor

  A tumor is an abnormal growth of body tissue. Tumors can be cancerous (malignant) or noncancerous (benign).

• Disease

  Asthma

  

  Asthma is an inflammatory disorder of the airways, which causes attacks of , shortness of breath, chest tightness, and coughing. See also:

• Disease

  Cushing syndrome

  

  Cushing syndrome is a disorder that occurs when your body is exposed to high levels of the hormone cortisol. It may also occur if you take too much cortisol or other steroid hormones. See also:

• Test

  ACTH

  

  An ACTH test measures ACTH, a hormone released from the anterior pituitary gland in the brain.

• Disease

  Pancreatic islet cell tumor

  

  A pancreatic islet cell is a rare tumor of the pancreas that starts from a type of cell called the islet cell.

• Disease

  Pheochromocytoma

  

  Pheochromocytoma is a rare of adrenal gland tissue. It results in the release of too much epinephrine and norepinephrine, hormones that control , metabolism, and blood pressure .

Review date:

March 18, 2008

Reviewed by:

Elizabeth H Holt, MD, PhD, Assistant Professor of Medicine, Section of Endocrinology and Metabolism, Yale University. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

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