<prompt> A common cause of Cushing syndrome is:Cancer producing ectopic ACTHPituitary adenomaAdrenal tuberculosisNone of the above  <response>: Answer is B Pituitary adenoma: Cushings Syndrome Endogenous Cushings Syndrome Most common cause of endogenous Cushings syndrome is an ACTH secreting pituitary adenoma Cushings disease Exogenous Cushings Syndrome The most common cause of exogenous Cushings syndrome is iatrogenic administration of steroids. ACTH producing pituitary adenoma are the most common cause of endogenous Cushing syndrome. 