In this patient with Cushing disease due to a pituitary adenoma, what is the best initial surgical intervention?

• A. Steroid taper
• B. Transsphenoidal surgery
• C. Adrenalectomy
• D. Ketoconazole

Answer: (B)

When Cushing disease is caused by a pituitary ACTH-secreting adenoma, the goal is to remove the source of excess ACTH. The best initial intervention is surgical removal of the pituitary tumor through a transsphenoidal approach. This route targets the tumor directly, offering the highest chance to normalize ACTH and cortisol with the least invasiveness compared with open brain surgery. If the tumor is successfully removed, cortisol levels often fall quickly, though temporary adrenal insufficiency may require short-term steroid replacement. Other options like tapering steroids would only be relevant if the Cushing state were from exogenous steroids, which isn’t the case here. Adrenalectomy would eliminate cortisol production but does not address the pituitary tumor and carries risks such as lifelong steroid dependence and Nelson syndrome. Medical therapies (e.g., ketoconazole) can control cortisol when surgery isn’t possible or as a bridge, but they are not first-line definitive treatment.