Here is a link about Pyneal Gland Cysts.
https://rarediseases.org/rare-diseas...s-symptomatic/
They are usually benign. If your symptoms that fit with pyneal gland cysts did not manifest until your concussion, then connecting such symptoms to the cyst is questionable. There is a huge overlap between PCS symptoms and pyneal gland cysts.
There is really nothing to worry about in my estimations. That is why your neuro did not mention it.