I agree with Little Lulu that talking with (another?) clinical endocrinologist is a good idea.

Writing as biomedical but not clinical health professional:

Cushing's syndrome refers to a number of signs which reflect elevated cortisol levels. Elevated cortisol is a known side-effect of taking prescription corticosteroid medication. Elevated cortisol can also arise elevated levels of ACTH, which "tells" the adrenal glands to make cortisol - your pituitary and ovarian tumours may be relevant here - measurements of your blood ACTH level could be of diagnostic value.

PCOS is less well understood. Its signs include elevated levels of male sex hormones, like testosterone. Possible causative factors include high insulin levels, low grade inflammation and genetics is a risk factor for it. To my knowledge elevated cortisol is not thought to be important.

I hope that this information helps you to ask your clinical endocrinologist(s) *lots* of questions.