hey!!! i have this too!!! it's so weird. i've had it a long time. it's tender to the touch, too. i'm pretty sure it's TMJ, because that's right where your jaw joint is... and sometimes TMJ can cause the joint to swell up. anyway, my lump moves around too. weird thing is, id on't really worry about it. it's been there so long i don't even care anymore. it hurts really badly when its cold outside... do you have that problem too?