R.J.
Its actually really common to find cysts and lesions in the ole noggin. Its one reason neurologists & docs avoid brain scans unless there are symptoms of note. Because even the idea is really freaky (even for neurology students, much less laymen).
Most self resolve.
Or just hang out for decades not causing any problems (brain is amazing).
If it does grow, those are AWESOME symptoms to have, because they're really noticeable, so the docs can go in and repair early.
The ones that are usually the most heartbreaking (in my experience) are ones adjacent next to cognitive areas (personality, reasoning, etc.) because those symptoms are often missed or shrugged off.
But with vision and paralysis... There will be super noticeable symptoms early. So they can be really proactive in dealing with it. Before permanent damage is caused.