ACTH (ectopic)

Last reviewed 06/2021

This is the production of adrenocorticotrophic hormone (ACTH) from a source other than the anterior part of the pituitary gland.

This phenomenon is usually associated with a small cell carcinoma of the bronchus. Less common causes include thymic tumours, pancreatic adenocarcinoma, bronchial carcinoid.


  • Cushingoid features may be present if the tumour is slow growing
  • features generally include:
    • generalized muscle weakness
    • mental abnormality
    • oedema (fluid retention)
    • diabetes
    • skin hyperpigmentation
    • hypokalaemic alkalosis
  • although metastasis to the adrenals often occurs with bronchogenic carcinoma a hormonal deficiency due to replacement is very unusual


  • no increased in steroid metabolites after metyrapone administration
  • no suppression of cortisol levels after dexamethasone administration


  • tumour resection or adrenalectomy
  • medical management includes the use of drugs such as the adrenolytic mitotane and aminoglutethimide