a corticotropin-secreting pituitary adenoma.p1536 Explanation:A corticotropin-secreting pituitary adenoma is the most common cause of Cushing's syndrome in women ages 20 to 40. Ectopic corticotropin-secreting tumors are more common in older men and are commonly associated with weight loss. Adrenal carcinoma isn't usually accompanied by hirsutism. A female with an inborn error of metabolism wouldn't be menstruating.