Identical Hand Twin

I just met my identical hand twin today. Some of you may have noticed but I have a bone that kind of sticks out on my left hand. If you look closely you'll see a round lump there. I have no idea how it got there. I've thought about it and concluded that I must've broken my hand when I was a kid and the bone didn't heal properly. Or something like that. Anyway, I just met somebody with the same hand as me, although it's located on her right hand! She's going to see a doctor today though so maybe it'll shed some light for me also when she gets diagnosed. I've never met anybody with this weird growth before. How exciting!