Jen,
My mother had a similar condition back in the early 1990s. She had headaches and vision trouble, and her pituitary gland had swollen to the point where it was pushing the optic nerves away from the eyes. This was never described as any type of cancer, so the endocrinologist is probably the best place to go. My mother did require surgery to have the gland removed. I think they were planning to only remove part of the gland, but once they started they found that it all had to be removed. She recovered in a few days and her vision was back to normal almost immediately. She did have to take meds every day after that to replace the hormones that would normally come from that gland. She did live for over 10 years after that surgery, and only passed away 6 years ago due to unrelated heart issues. Hope this helps. Good luck!