Why do pituitary tumors recur?
Even with successful surgery (remission of hormone over production and/or no visible tumor on the post operative MRI scan), the most likely reason that a tumor recurs is that a few tumor cells that cannot be seen, even with the operating microscope, remain. Over time, these cells grow and divide and produce a new tumor. It is important to emphasize that even when all visible tumor is removed, there may be a few remaining cells in the area of the original tumor or in an area that cannot be removed surgically (tumor cells invading the bone [sellar bone] below the pituitary, invading the membrane [dura] around the pituitary, and/or invading the cavernous sinus [area on each side of the pituitary that contains the artery that provides blood to the front part of the brain and nerves that control eye movements]). Patients who have had surgery and/or radiation for a pituitary tumor often have loss of pituitary hormone production requiring hormone replacements, including growth hormone. The po
