Ciftci, SemaSoyluk, OzlemSelek, AlevErol, SelvinazHekimsoy, ZelihaEsen, AyseDursun, HuseyinSahin, SerdarOruk, GoncaMert, MeralSoylu, HuseyinYurekli, Banu SarerErtorer, Melek EdaOmma, TulayEvran, MehtapAdas, MineTanrikulu, SeherAydin, KadriyePekkolay, ZaferCan, BulentKarakilic, ErsenKaraca, ZuleyhaBilen, HabibCanturk, ZeynepCetinarslan, BerrinKadioglu, PinarYarman, Sema2022-12-022022-12-0220220018-5043http://hdl.handle.net/11727/8202The purpose of this study was to determine possible cut-off levels of basal DHEA-S percentile rank in the differential diagnosis of patients with Cushing's syndrome (CS) with ACTH levels in the gray zone and normal DHEA-S levels. In this retrospective study including 623 pathologically confirmed CS, the DHEA-S percentile rank was calculated in 389 patients with DHEA-S levels within reference interval. The patients were classified as group 1 (n=265 Cushing's disease; CD), group 2 (n=104 adrenal CS) and group 3 (n=20 ectopic ACTH syndrome).ROC-curve analyses were used to calculate the optimal cut-off level of DHEA-S percentile rank in the reference interval in the differential diagnosis of CS, and the effectiveness of this cut-off level in the identification of the accurate etiology of CS was assessed in patients who were in gray zone according to their ACTH levels. The DHEA-S percentile rank in the reference interval were significantly lower in group 2 compared to the other two groups (p<0.001), while group 1 and group 3 had similar levels. The optimal cut-off level of DHEA-S percentile rank in the reference interval providing differential diagnosis between group 1 and group 2 was calculated as 19.5th percentile (80.8% sensitivity, 81.5% specificity) and the level demonstrated the accurate etiology in 100% of CD and 76% of adrenal CS patients who were in the gray zone. This study showed that the cut-off value of DHEA-S level less than 20% of the reference interval could be used for differential diagnosis of CD and adrenal CS with high sensitivity and specificity, and it should be taken into the initial evaluation.enginfo:eu-repo/semantics/closedAccessCushing's diseaseadrenal Cushing's syndromeectopic ACTH syndromedehydroepiandrosterone-sulfateDHEA-S cut-offdifferential diagnosisarticle5442322370007821826000052-s2.0-85128145098