Ectopic Cushing syndrome Health Article

Definition

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

Alternative Names

Cushing syndrome - ectopic

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