19 year old woman with menstrual disorders, headaches, mood disorders and hints of male hair. Laboratory findings: more than twice as high ACTH levels, almost twice as high cortisol levels, slightly elevated prolactin levels, slightly elevated testosterone levels (at 8:00 am) and a small enlargement of the pituitary gland with an adenoma-suspicious area of 6 X 4 X 3 mm on MRI. Is further diagnostic useful (PET)?