What Do The Findings Synaptophysin Highlights Background Neuropil Consistent With An Infiltrative Growth Pattern Mean About A Brain Tumor?

Hi, I was recently analyzing a pathology report from a brain tumor biopsy, and I had a question about what certain findings indicated or meant. Specifically, synaptophysin highlights background neuropil consistent with an infiltrative growth pattern, and NeuN is positive in the infiltrative native neurons. What do these two things mean about the nature of the tumor? To clarify, I am not asking what kind of brain tumor these indicate (if that makes sense). I am asking more, why is this important to know? What do they literally mean? Thank you.