During transsphenoidal resection of pituitary tumors and cysts, surgery is performed by a neurosurgeon and ear nose and throat surgeon. The pituitary tumor or cyst is reached by making a small hole in the back of the nose into the bottom of the skull. The surgeon is able to see the pituitary and tumor with an endoscope and remove the tumor through the hole.

Surgery on the pituitary can cause disruption in the secretion of ACTH and cause adrenal failure (lack of cortisol secretion) which can cause nausea, vomiting, low blood pressure, and rarely can be fatal. There is no consensus among endocrinologists and neurosurgeons about the use of perioperative steroids in pituitary patients. Traditionally, all patients undergoing pituitary surgery were given steroids before, during, and after surgery because of the assumption that there would be some compromise in the amount of ACTH released by the pituitary as a result of surgical trauma. Studies have failed to show, however, that ACTH secretion is in fact compromised during transsphenoidal pituitary microsurgery. As a result, there are some centers that routinely give perioperative steroids to all patients undergoing pituitary surgery and there are some centers that do not routinely give perioperative steroids. There are several retrospective and prospective studies that have addressed this issue and have shown that withholding perioperative steroids is safe, but there has never been a prospective study comparing the two approaches.

Objectives: The goal of this study is to prospectively compare two approaches to the perioperative management of patients undergoing transsphenoidal resection of a pituitary tumor or cyst. One protocol includes the routine use of perioperative steroids and the other does not. The investigators hypothesis, based on previous studies, is that patients who are adrenally sufficient do not routinely need to be treated with perioperative steroids. The investigators also hypothesize that the use of perioperative steroids may be associated with a higher rate of adverse outcomes

Patients who are scheduled to undergo transsphenoidal resection for a pituitary tumor or cyst at the investigators institution will be screened prior to surgery for eligibility for this study. All patients deemed eligible will undergo a cosyntropin stimulation test to evaluate for adrenal insufficiency. Patients with adrenal insufficiency will be excluded from the study.

Inclusion Criteria:

• Any adult patient with a pituitary adenoma or cyst (either non-functioning, prolactin secreting, growth hormone secreting, gonadotropin secreting, or TSH (Thyrotropin secreting hormone) scheduled to undergo transsphenoidal resection.

Exclusion Criteria:

• Patients with Cushing's Disease (pituitary tumor which secretes ACTH)
• Patients with a history of pituitary apoplexy (condition caused by hemorrhage into a pituitary adenoma which causes headache, double vision and hypopituitarism)
• Patients on long term glucocorticoid therapy
• Patients with adrenal insufficiency or who have not had their adrenal response evaluated prior to surgery