Snapshot A 42-year-old obese woman who does not smoke presents with diastolic hypertension and menstrual irregularities. Physical exam shows a full, plethoric-appearing face, increased facial hair, truncal obesity, and purple striae around the abdomen. Scattered echymoses are present over the entire body. Labs show a Hgb of 18 g/dL and a WBC of 18,000/mm^3. The leukocyte differential shows an absolute neutrophillic leukocytosis. CXR is normal. Introduction A condition that refers to the manifestations of hypercortisolism results in hyperplasia of the adrenal cortex specifically the fasiculata There are several types iatrogenic Cushing's patients taking steroids is the most common cause of Cushing's syndrome pituitary adenoma (Cushing's disease) most common pathogenic cause (70%) majority of adenomas are benign cause bilateral hyperplasia of the adrenal glands associated increase in conversion of norepinephrine to epinephrine in medulla enzyme involved is phenylethanolamine n-methyltransferase adrenal Cushing's adenoma of the adrenals ectopic Cushing's ectopic ACTH secretion extremely high ACTH most commonly from small cell carcinoma of the lung less commonly thymic cancer Presentation Symptoms depression and psychological changes oligomenorrhea growth retardation weakness catabolism of muscle for gluconeogenesis symptoms of diabetes (polydipsia, polyuria, and dysuria) Physical exam diastolic hypertension central obesity muscle wasting thin skin that easily bruises/purple abdominal striae due to weakening of collagen hirsutism moon facies buffalo hump Evaluation Labs hyperglycemia cortisol is gluconeogenic hypokalemia at high concentrations cortisol can have partial activity at the aldosterone receptor screen for 24-hour free urinary cortisol as well as a serum cortisol level high positive and negative predictive value serum ACTH to localize lesion iatrogenic ↓ ACTH pituitary ↑ ACTH adrenal ↓ ACTH ectopic ↑ ACTH if ACTH is high, then use high dose dexamethasone suppression test pituitary ↓ cortisol production (i.e. production is suppressible) ectopic no change in cortisol (i.e. production is NOT suppressible)