Pseudo-Cushing's syndrome

Diagnosis

• Levels of cortisol and ACTH both elevated
• 24-hour urinary cortisol levels elevated
• Dexamethasone suppression test
• Late night salivary cortisol
• Loss of diurnal variation in cortisol levels
• High mean corpuscular volume and gamma-glutamyl transferase may be clues to alcoholism
• Polycystic Ovarian Syndrome should be ruled out; PCOS may have similar symptoms

  Differential diagnosis

• Differentiation from Cushing's is difficult, but several tools exist to aid in the diagnosis
• Alternative causes of Cushing's should be excluded with imaging of lungs, adrenal glands, and pituitary gland; these often appear normal in Cushing's
• In the alcoholic patient with pseudo-Cushing's, admission to hospital will result in normal midnight cortisol levels within five days, excluding Cushing's
• Another cause for Cushing's syndrome is adrenocortical carcinoma. This is a rare form of cancer with an incidence of 1-2 per million people annually. About 60% of these cancers produce hormones, with cortisol being the most frequent. Most patients present in an advanced disease state and the outcome is dismal.

  Prognosis

• Blood results and symptoms normalise rapidly on cessation of drinking or remission of depression.