Hi there! I would suggest looking to the American Brain Tumor website (abta.org) as well as the National Brain Tumor Foundation website (NBTF.org or braintumor.org). They were both very helpful to me when I was going through my diagnosis and surgery/recovery for my brain tumor.

What I know about Oligo's is that they are considered low grade tumors (meaning typically benign and not very aggressive). They are not a very common tumor type to have but one of the "better" ones if there is such a thing.