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Ectopic Cushing syndrome

  • 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