Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content +++ INTRODUCTION ++ Hyperfunction of the adrenal glands involves excess production of the adrenal hormones cortisol (resulting in Cushing syndrome) or aldosterone (resulting in hyperaldosteronism). Adrenal gland hypofunction is associated with primary (Addison disease) or secondary adrenal insufficiency. +++ CUSHING SYNDROME +++ PATHOPHYSIOLOGY ++ Cushing syndrome results from effects of supraphysiologic glucocorticoid levels originating from either exogenous administration or endogenous overproduction by the adrenal gland (adrenocorticotropic hormone [ACTH] dependent) or by abnormal adrenocortical tissues (ACTH independent). ACTH-dependent Cushing syndrome (80% of all Cushing syndrome cases) is usually caused by overproduction of ACTH by the pituitary gland, causing adrenal hyperplasia. Pituitary adenomas account for about 85% of these cases (Cushing disease). Ectopic ACTH-secreting tumors and nonneoplastic corticotropin hypersecretion cause the remaining 20% of ACTH-dependent cases. Ectopic ACTH syndrome refers to excessive ACTH production resulting from an endocrine or nonendocrine tumor, usually of the pancreas, thyroid, or lung (eg, small-cell lung cancer). ACTH-independent Cushing syndrome is usually caused by adrenal adenomas and carcinomas. +++ CLINICAL PRESENTATION ++ The most common findings in Cushing syndrome are central obesity and facial rounding (90% of patients). Peripheral obesity and fat accumulation occur in 50% of patients. Fat accumulation in the dorsocervical area (buffalo hump) is nonspecific, but increased supraclavicular fat pads are more specific for Cushing syndrome. Patients are often described as having moon facies and a buffalo hump. Other findings may include myopathy or muscular weakness, abdominal striae, hypertension, glucose intolerance, psychiatric changes, gonadal dysfunction, facial plethora (a reddish complexion), and amenorrhea and hirsutism in women. Up to 60% of patients develop Cushing-induced osteoporosis; about 40% present with back pain, and 20% progress to spinal compression fractures. +++ DIAGNOSIS ++ Hypercortisolism can be established with one or more of the following tests: 24-hour urinary free cortisol (UFC), midnight plasma cortisol, late-night (11 PM) salivary cortisol, and/or low-dose dexamethasone suppression test (DST). Other tests to determine etiology are plasma ACTH test; adrenal vein catheterization; metyrapone stimulation test; adrenal, chest, or abdominal computed tomography (CT); corticotropin-releasing hormone (CRH) stimulation test; inferior petrosal sinus sampling; and pituitary magnetic resonance imaging (MRI). Adrenal nodules and masses are identified using high-resolution CT scanning or MRI. +++ TREATMENT ++ Goals of Treatment: Limit morbidity and mortality and return the patient to a normal functional state by removing the source of hypercortisolism while minimizing pituitary or adrenal deficiencies. Treatment plans in Cushing syndrome based on etiology are included in Table 18–1. ++Table Graphic Jump LocationTABLE 18–1Treatment Options in Cushing Syndrome Based on EtiologyView Table||Download (.pdf) TABLE 18–1 Treatment Options in Cushing Syndrome Based on Etiology Etiology Nondrug Generic (Brand) Drug Name Dosing Initial Dose Usual Range Maximum Ectopic ACTH syndrome Surgery, chemotherapy, irradiation Metyrapone (Metopirone) 250 mg capsules 0.5–1 g/day, divided every 4 to 6 hours... Your MyAccess profile is currently affiliated with '[InstitutionA]' and is in the process of switching affiliations to '[InstitutionB]'. Please click ‘Continue’ to continue the affiliation switch, otherwise click ‘Cancel’ to cancel signing in. Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Username? Forgot Password? Sign in via OpenAthens Sign in via Shibboleth