With the limited information provided, I can not provide a specific diagnosis. I am not sure what literature you have been reading, but based on your description this cyst is not in the brain. An imaging study of the area may help to define what structures are involved. I would recommend asking the specialist what the cyst is and what is the prognosis. Without more information, this is as specific as I can be. Sorry I could not be of more help.
Peace, Jane