Abstract
Cushing's disease (CD) is a rare illness characterized by chronic hypercortisolism secondary to the overproduction of adrenocorticotropic hormone by a pituitary adenoma, which is associated with a high risk of developing serious complications, such as diabetes mellitus, cardiovascular disease, and emotional disorders. Endoscopic transsphenoidal surgery is performed for the treatment of CD, and was initially preferred over other types of treatments. However, the recurrence after pituitary surgery for CD is a common problem after an initial successful surgery. In microadenomas, the remission rates were higher than those of macroadenoma. This patient had a giant tumor that was greater than 4 cm in length on sella magnetic resonance imaging, and panhypopituitarism was detected using a combined pituitary stimulation test. After transsphenoidal surgery, the patient required temporary hormone replacement for a short period of time. After 1 year, he showed a normal cortisol response on the overnight dexamethasone suppression test and low morning cortisol levels. Therefore, we indicated that the patient was cured of giant macroadenoma with panhypopituitarism before surgery, and thus, reported this case.