Lisa,
Is this tumour in your brainstem or outside of it? If it is a low grade tumour then I suspect they have found it to be focal (and not a fast growing malignant tumour).

It's not something anyone would like to have, but be thankful at least that it is not a high grade glioma, which my toddler had within his brainstem.

I suspect they will need to give you regular checks, to see whether there is any change to the tumour. It is far too risky to operate on it, as it is in such a delicate part of the brain, that an op can cause more harm than good.

So long as you feel fine and continue to go for checks, then hopefully you should be OK.

Take care