Have just started reading this and I think it should be very good. More teen fiction - as I'm too busy at work to keep going with anything that needs a great deal of concentration at the moment - the blurb goes;

It was just supposed to be a routine exam. But when the doctors snake the fiber-optic tube down Robert Smith's throat, what they discover doesn't make medical sense. Plastic casings. Silver filaments. Moving metal parts. In his naked, anesthetized state on the operating table, Robert hears the surgeons' shocked comments: "What the hell is that?" "It's me," Robert thinks, "and I've got to get out of here." Armed with a stolen automatic and the videotape of his strange organs, he manages to escape, and to embark on an orphan's violent odyssey to find out exactly who--exactly what--he is.