YA Sci-Fi book, boy abducted and returns years later and hasn't aged

[Christian]

I read this book in the early 2000s or maybe listened to it on tape. There was a boy who went missing and shows up years later and has not aged. I believe he is in a store or something and sees his picture on a missing persons thing or a milk carton or something and faints. He is reunited with his family and is allowed to continue school in the grade he should be in, but it is odd because he has not aged since he disappeared. His best friend has kind of abandoned him as well. He has some health problems because there is something in his brain and he needs a surgery to remove it, there is only like a one in ten chance he will live. Then some people want to take him to aliens to get it removed I think? Any help appreciated!

[Ayshe]

The Door in the Lake by Nancy Butts maybe?

[Lobstergirl, au gratin]

Christian, are you still looking for this or did you find it?

[Rainbowheart]

I agree with Ayshe.

It sounds like the author got the idea from the Disney movie Flight of the Navigator, but there was never a book version of that as far as I now.