TSH is one pituitary test, but it is not enough. If the MRI did reveal a pituitary tumor, then you should go find a neuro-endocrinologist and get tested and treated for that lesion.
The smell is likely an infection. I had one of those at one time and it was awful since there is no way to escape it! Find a good ENT and you may need debridement to get all the yuck out, as well as a lot of saline to rinse rinse rinse.
The MRI was ordered because I gave my doc. some information on a woman who had a smell that was in her head and could not get rid of it. I told my doc. I am experiencing a smell that is undescriable and no one else can detect/smell it just me. etc. So I went and the MRI and it said I have a small tumor pituitary adenoma gland so the MRI did reveal the tumor. It said the optic chiasm is not compressed it appears normal & the Sella turcia is normal. The sinuses appear to be normally aerated and the mastoids show no opacification. I took blood work for TSH.
Are you sure they did not term it as partial empty sella syndrome?
A neurologist does not treat pituitary. Cancel that appointment and instead go see an endocrinologist.
You said nothing about symptoms or why you had an MRI. Was the MRI dynamic?