Barros Amanda P T, Lamback Elisa B, Coelho Maria Caroline A, Neto Leonardo Vieira
AACE Clin Case Rep. 2018 Oct 5;5(2):e91-e94. doi: 10.4158/ACCR-2018-0336. eCollection 2019 Mar-Apr.
Cushing syndrome (CS) is one of the most challenging diseases to diagnose due to the difficulties that may arise during laboratory test interpretations. A random serum cortisol level is often obtained by a general practitioner as a first step in the work-up of suspected CS patients. In this respect, it is rarely useful and has limitations.
We report an extremely unusual case of a female patient who presented with adrenocorticotropic hormone-independent CS and corticosteroid-binding globulin (CBG) deficiency.
The patient was initially misdiagnosed with and treated for adrenal insufficiency because of persistently low basal cortisol levels, in detriment of her exacerbated Cushing features and symptoms.
We describe the limitations of using basal cortisol in the diagnosis of CS and review the differential diagnosis of patients with CS who have low basal cortisol. CBG variants may explain the findings of high urinary and salivary cortisol, in the absence of increased serum cortisol.
库欣综合征（CS）是最难诊断的疾病之一，因为在实验室检查结果解读过程中可能会出现困难。全科医生通常会首先测定随机血清皮质醇水平，作为疑似CS患者检查的第一步。在这方面，它很少有用且存在局限性。
我们报告了一例极为罕见的女性患者，该患者表现为促肾上腺皮质激素非依赖性CS和皮质类固醇结合球蛋白（CBG）缺乏。
该患者最初因基础皮质醇水平持续偏低而被误诊为肾上腺功能不全并接受治疗，这对其加重的库欣特征和症状不利。
我们描述了使用基础皮质醇诊断CS的局限性，并回顾了基础皮质醇水平低的CS患者的鉴别诊断。CBG变异可能解释在血清皮质醇未升高的情况下尿和唾液皮质醇升高的现象。
