Juszczak Agata, Morris Damian, Grossman Ashley
Consultant in Endocrinology and Diabetes, University Hospital Birmingham NHS Fundation Trust, Birmingham, UK
Consultant in Endocrinology and Diabetes, East Suffolk and North Essex NHS Foundation Trust, Ipswich, UK
Cushing’s syndrome results from chronic exposure to excessive circulating levels of glucocorticoids. Cushing’s disease, pituitary-dependent Cushing’s syndrome, is the most common cause of endogenous hypercortisolism. The recommended screening tests include the 1mg overnight dexamethasone suppression test, late-night salivary cortisol (at least 2 samples), and 24-hour urinary free cortisol (at least two 24-hour collections). If the initial test is positive on 2 occasions the patient should be evaluated by an endocrinologist for further assessment. Plasma 09:00h ACTH measurement guides imaging and further investigations. If ACTH is elevated/inappropriately normal, MRI scanning of the pituitary should be performed, but if ACTH is suppressed imaging of the adrenals should follow. The corticotrophin releasing hormone (CRH) or desmopressin tests helps distinguishing pituitary from ectopic ACTH-dependent Cushing's syndrome, while bilateral petrosal sinus sampling remains the gold standard test and should be considered, if available, with the exception of the presence of a pituitary macroadenoma. It is prudent to perform a CT of the thorax, abdomen and pelvis in all patients. Transsphenoidal surgery is the first line treatment for Cushing’s disease, followed by radiotherapy as a second-line option. Adrenalectomy is the first-choice treatment for adrenal ACTH-independent Cushing’s syndrome and resection of the ACTH source should be performed for the ectopic ACTH-dependent Cushing’s syndrome, where possible. Bilateral adrenalectomy can always be considered as an option. Steroidogenesis inhibitors remain the most effective medical agents and are useful when surgery or the effects of radiotherapy are awaited or are unsuccessful. For complete coverage of all related areas of Endocrinology, please visit our on-line FREE web-text, WWW.ENDOTEXT.ORG.
库欣综合征是由于长期暴露于循环中糖皮质激素水平过高所致。库欣病，即垂体依赖性库欣综合征，是内源性皮质醇增多症最常见的病因。推荐的筛查试验包括1毫克过夜地塞米松抑制试验、午夜唾液皮质醇（至少2份样本）和24小时尿游离皮质醇（至少2次24小时收集）。如果初始试验两次呈阳性，患者应由内分泌科医生进行评估以进一步检查。上午9点的血浆促肾上腺皮质激素（ACTH）测量指导影像学检查和进一步的调查。如果ACTH升高/正常但不适当，应进行垂体磁共振成像扫描，但如果ACTH被抑制，则应进行肾上腺成像检查。促肾上腺皮质激素释放激素（CRH）或去氨加压素试验有助于区分垂体性与异位ACTH依赖性库欣综合征，而双侧岩下窦采血仍是金标准试验，如有条件应考虑进行，垂体大腺瘤患者除外。对所有患者进行胸部、腹部和骨盆CT检查是谨慎的做法。经蝶窦手术是库欣病的一线治疗方法，其次是放疗作为二线选择。肾上腺切除术是肾上腺ACTH非依赖性库欣综合征的首选治疗方法，对于异位ACTH依赖性库欣综合征，应尽可能切除ACTH来源。双侧肾上腺切除术始终可作为一种选择。类固醇生成抑制剂仍然是最有效的药物，在等待手术或放疗效果或手术或放疗不成功时很有用。欲全面涵盖内分泌学的所有相关领域，请访问我们的在线免费网络文本，网址为WWW.ENDOTEXT.ORG。
