How do you manage adult brainstem lesions in the absence of a tissue diagnosis?

I would:

1. Discuss with the neuro-radiologist and obtain another imaging study(e.g. PET or MR perfusion) that could support the MRI diagnosis of high grade glioma.
2. Have a thorough discussion at a multi-disciplinary neuro-oncology tumor board to make sure surgical biopsy is unsafe and there is consens...