Pretty much doctors will do hormonal testing before they order a MRI to see if it is caused by a pituitary tumor. The reason why is that some studies suggest up to 25% of the population do have pituitary tumors, and the majority of those don't present with clinical symptoms. Having a pituitary tumor doesn't mean automatic surgery. If you have a hormone secreting tumor, that secretes prolactin, the first line of therapy is a dopamine agonist. If you have a hormone secreting tumor that secretes GH or ACTH, or even more rarely, TSH, the first line of therapy is surgery. Some studies are going on though, that suggest using somastatin as a first line of therpay with treating GH tumors. If your tumor is not hyper secreting hormones, then the approach to manage microadenoams (tumors under 10mm) is often watch for growth, and for tumors over 10mm, watch for growth, but if there is compression of adjacent brain structures (such as the optic nerve and other areas of the brain), surgery is often indicated. Many tumors are simply watched. It is true that some pituitary tumors can cause the pitutiary deficiencies as they grow, but surgery is often reserved and carefully considered, because... it is skull base surgery and it is invasive and surgery poses risk. Do have a good talk with your doctor. You can read more here: | 