Why are pituitary tumors so hard to diagnose?

They are very small: These tumors secrete very powerful hormones that have far reaching affects on the body but many times the tumors are so small and also protected in the skull that they are not seen on standard imaging. Special imaging studies are needed many times to detect the tumors. Also, many of these hormones can be measured in the blood and if elevated, the search for the tumor is intensified.

Cellular level: The pituitary is a complex organ with many complex cells and interconnections. Normal changes in cell growth and hormone section is happening all the time. When these normal cell changes get out of control it may be very difficult to tell until they are very abnormal. No one test can be the answer.

It depends: Fortunately, in the era of modern medicine, diagnosis is typically not all that difficult. Mri is generally quite reliable in diagnosing pituitary tumors. Otherwise, eye exam (visual field testing) and blood hormone tests are important in diagnosing pituitary tumors. Prior to the age of accurate intracranial imaging, these tumors were indeed more difficult to diagnose.