Below is a link to the scene from Spider-Man 3 where Flint Marko, one of the villains in the movie, becomes the infamous Sandman. In this scene, Flint is running away from the cops and falls into a pit where an experiment is being conducted. The scientists do not realize that a man is in the pit of sand, and start the turbines, which cause the sand particles to move rapidly in the pit. They collide with Flint and change his very cells to sand crystals.
https://www.youtube.com/watch?v=vTT3l-N6Au4
Why this is Medical Discrimination:
In this case, although the scientists are not to blame for changing Flint's skin structure, the circumstances leading to that point are.