I've heard of that happening with stretched piercings, usually as a blowout or keloid scar. I've also heard of people cutting them off themselves. I know that for me personally, I wouldn't want to try removing them myself. There are some piercers who specialize in scalpelling and dermal punches that could probably do that kinda thing. Your best bet is to check out
www.bmezine.com and look for anything on keloids or "blowouts".