Hard boney growth at anterior aspect of radial head?

What could this be? It covers a small area but sticks out a lot. I also have pain down the palmer aspect of the 1st metacarpal and it is painful when i move my thumb. The head of radius feels jagged, knobly and gives me a dull aching sensation. The same area on the contralateral side feels normal and I have had no pain there. I had pain in a similar area 6 months ago. I'm not sure when the bump started or whether I have always had it as I only felt it last night because my wrist really hurt. I do a lot of repetative movements with my wrist at work and I'm right handed and its on my right side. I do not know if that is anything to do with the hard boney bump though.