The diagnosis and differential diagnosis of endogenous Cushing's syndrome

cushing'ssyndrome �(cs)�isaphysicallyandpsychologicallydisablingdiseaseassociated� withhighmorbidityresultingfrominappropriateelevationofcirculatingfreecortisollevels.� themainfeaturesofcsaredisturbanceofthenormalcircadianrhythmofcortisolsecretion,� impairmentofthenormalfeedbackofthehypothalamo-pituitary-adrenal �(HPA)-axis,�and� excessiveintegrated� 24�hourscortisolsecretion.� Allbiochemicaltestsusedforthediagnosis� ofcsrelyupontheascertainmentofadisturbanceofthesefeatures.� However,�thediagno- sisofcs�(endogenoushypercortisolism)� stillremainsachallenge,�althoughtheevolutionof� severaldiagnostictestshasalloweddiagnosisatanearlierstage.� Intheinitialinvestigation� ofcs,�testsofhighsensitivityarerequiredtoidentifypatientsatrisk,� whicharefollowedby� testsofhighspecificitytoconfirmthediagnosisandestablishthepreciseaetiology.�thisre - viewwilldiscussthevariouscausesofendogenouscsandfocusonestablishedandevolving� diagnosticproceduresusedforitsdiagnosis,�asseveralstudieswithlargenumberofpatients� haverecentlyappearedintheliteraturevalidatingcurrentpracticeandproposingimproved� diagnosticalgorithms.