Neurologist suspects a low grade oligodendroglioma, yet says too small to biopsy?

Hi all. I am a 45 year old woman who was sent to a neurologist for, of all things, ear pain. The neurologist suspected MS due to some abnormalities with my neuro exam. He also thought the ear pain was related. To make a long story short, he ordered an MRI of my brain which showed a 5mm lesion. He told me that to him, this looked like a low-grade oligodendroglioma and he wants to do a repeat MRI in early November. MS was subsequently taken off the table completely. When I asked about having the lesion biopsied, he replied that I wouldn't be able to find a neurosurgeon in the country who would be willing to biopsy at this time. Thoughts? I am very scared and the thought of this being in my brain and potentially growing is very nerve wracking to say the least! I should add, I had a head CT just 10 months prior that was completely normal. Neurologist agrees this is a 'new' finding. Thank you in advance for any thoughts, insights, or advice.