There's the possibility to get silicon implants on your chest and bottom and you've got synthol. Synthol is an oil that some people inject in their mucles to give them more volume.
Both options look retarded though.
Here's a picture of synthol king Greg Valentino, he used to have a rather good physic for a bodybuilder untill he started messing around with synthol.
Just clearing up, this guy
does get laughed at in muscle land.
Lot's of american youngsters inject it in their biceps to look cool at the club. It looks really unnatural because you get the average skinny guy with a pumped up bicep. It's also rather dangerous plus your muscle doesn't get any stronger.
I've never heard of adding real muscle structure on the already exsisting muscle though.