<prompt> Which of the following is characteristic of Cushings disease:Incresed ACTH. increased cortisolDecreased ACTH, increased cortisolIncreased ACTH. decreased cortisolDecreased ACTH. decreased cortisol  <response>: Ref: Davidson 21st edition, pg 771Explanation:Cushings syndrome refers to clinical features due to chronic exposure to excess of glucocorticoids of any etiology.Its of 2 types:ACTH- dependent Cushings: Pituitary adenoma secreting ACTH Cushings disease, ectopic ACTH syndrome Lung carcinoid, small cell ca lung, medullary ca thyroid, pheochromocytoma.ACTH- independent Cushings: Iatrogenic chronic glucocorticoid therapy, adrenal adenoma, adrenal carcinoma Cushings disease is due to a pituitary adenoma secreting ACTH.Pituitary microadenoma in 90Cushings syndrome is caused by excess activation of the GR Glucocorticoid receptorAnterior Pituitary-- ACTH -Adrenal cortex Cortisol GR--Pseudo-Cushings: Cortisol excess as a part of other illnessSeen in alcohol excess, chronic depression primary obesityCarneys complex: cardiac myxomas, hyperlentiginosis, Sertoli cell tumor PPAND Primary Pigmented Nodular Adrenal DiseaseMcCune- Albright syndrome- Polyostotic fibrous dysplasia, precocious puberty cafe- au-Iait spotsScreening tests: 24hr urinary free cortisol. Overnight dexamethasone test.-- Low dose dex testTreatment: Surgery for adrenal tumorsCushings disease-removal of pituitary tumor via transsphenoidal approach; bilateral adrenalectomy for recurrenceOral agents for Cushings syndrome- metyrapone, ketoconazole, mitotaneIV etomidate in severe cases. 