Cushing syndrome: update on testing

Endocrinol Metab Clin North Am. 2015 Mar;44(1):43-50. doi: 10.1016/j.ecl.2014.10.005. Epub 2014 Nov 4.


Endogenous hypercortisolism (Cushing syndrome) is one of the most enigmatic diseases in clinical medicine. The diagnosis and differential diagnosis of Cushing syndrome depend on proper laboratory evaluation. In this review, an update is provided on selected critical issues in the diagnosis and differential diagnosis of Cushing syndrome: the use of late-night salivary cortisol in initial diagnosis and for postoperative surveillance, and the use of prolactin measurement to improve the performance of inferior petrosal sinus sampling to distinguish Cushing disease from ectopic adrenocorticotropic hormone (ACTH) syndrome during differential diagnosis of ACTH-dependent Cushing syndrome.

Keywords: Adrenal incidentalomas; Cushing disease; Inferior petrosal sinus sampling; Salivary cortisol.

Publication types

  • Review

MeSH terms

  • Cushing Syndrome / diagnosis*
  • Cushing Syndrome / metabolism
  • Humans
  • Hydrocortisone / analysis*
  • Prolactin / analysis*


  • Prolactin
  • Hydrocortisone