There was a post a while back about a bodybuilder who was wheelchair bound and had developed an awesome upper body despite. Well I came across this guy Robert Siudak and thought I'd share this as well.
Robert states: "I was diagnosed with bone cancer in 1990. I had my left leg amputated in 1992. I train my right leg with leg presses, leg curls, leg extensions and hack squats. I just use my prosthesis for balance on the hack squats; and then on the leg press I just press with the one leg."
It says on his MySpace page that he recently had a heart transplant and is of course no longer competing but didn't go into detail. The saying "whatever doesn't kill you only makes you stronger" definitely applies to this guy!