Mason's Brain Cyst..

Well we met with our neurosurgeon last week, and he informed us that Mason will most likely undergo brain surgery by the time he is 2 to remove this cyst on his brain. In case you don't know, Mas was born with an arachnoid cyst on the right side of his brain. He has an MRI every 6 months to monitor it. 6 months ago it had grown slightly, but not at an alarming rate, this MRI showed something much different that his neurologist had never seen before. The cyst changed shape. Dr. L thinks that it grew an added bubble on it but is being compressed, so it is staying the same size, because it is being pushed down, but technically growing.  This cyst is placed more in the middle, and in a very tricky, hard to reach spot. I would love to get a 2nd opinion though, just for someone else's input.