Which of the following statements is true with respect to Cushing Disease?

a. Pituitary microadenomas are often small and deep within the gland itself

c. Patients who fail to remit with both surgery and radiation to the pituitary require either medical or surgical adrenalectomy

Pituitary microadenomas secreting ACTH may be very small and are often located deep within the gland itself. If the tumor is not evident on opening the dura, incisions must be made into the gland and internal exploration carried out. If no tumor is identified, then a decision must be made as to whether to resect all or a portion of the gland. If the endocrine evidence is convincing for pituitary origin and the patient has no desire to have children, then total hypophysectomy is warranted. If the petrosal sinus sampling clearly indicates laterality then appropriate hemiresection of the gland may be done.

About 75% of patients have microadenomas as the source of ACTH secretion. The postoperative remission rate in these patients is 88% to 96%, and the long-term recurrence rate appears to be no more than 5%. 10% to 20% of patients who undergo exploration have macroadenomas, and the postoperative remission rates in these patients have been reported to be from 33% to 61%. Most of these patients require postoperative radiation therapy. Patients who fail both surgery and radiation require either surgical adrenalectomy or medical suppression of adrenal function.