Which of the following statements about Cushing’s disease is true?
Cushing’s syndrome is due to increased adrenal cortisol production, regardless of etiology.
Cushing’s disease usually is caused by a pituitary microadenoma producing high adrenocorticotropin (ACTH) levels.
In most patients, cortisol levels would be suppressed as a result of the high-dose dexamethasone suppression test.
Transsphenoidal microsurgical removal of the microadenoma is the treatment of choice in most centers.
Serum adrenocorticotropin (ACTH) levels usually are low
Pituitary microadenoma usually is present
There is a high incidence of nonendocrine tumors
Nonsuppression of cortisol production by the high-dose dexamethasone suppression test is a characteristic finding