[Morbidity and mortality in Cushing's syndrome]

Endogenous Cushing's syndrome is a rare endocrine disorder that is fatal if left untreated. It can be distinguished into adrenocorticotropic hormone (ACTH)-dependent (central and ectopic Cushing's syndrome) and ACTH-independent subtypes (unilateral or bilateral adrenal adenomas). The clinical presentation of patients includes typical stigmata of cortisol excess with physical symptoms of catabolic metabolism (myopathy, striae, parchment skin, osteoporosis) and components of metabolic syndrome (diabetes mellitus, obesity, arterial hypertension, hypercholesterolemia). Biochemical diagnosis is performed in three steps: 1. Confirmation of the diagnosis by 1‑mg dexamethasone suppression test, 24‑h urine free cortisol, and measurement of late-night salivary cortisol. 2. Differentiation of ACTH-dependent Cushing's syndrome from ACTH-independent adrenal Cushing's syndrome by measurement of plasma ACTH. 3. Further subtyping by corticotropin-releasing hormone (CRH) test, inferior petrosal sinus sampling, and imaging modalities. Therapeutic decisions are made on an interdisciplinary basis. First-line therapy for all subtypes is surgery when possible; additional options for all forms include drug therapy and bilateral adrenalectomy. Despite adequate treatment, Cushing's syndrome is associated with increased long-term morbidity and mortality. Interdisciplinary and multimodal therapy management is necessary in the long term to positively influence mortality and reduced quality of life.