some info as to where the pain is in the knee. ie is it the inside,outside, top ,bottom, centre,front,back etc. also what makes it hurt and what helps reduce pain if anything. does it ever swell , lock up or give way. some of this type of info would be useful. have you had an accident involving your knee?

i doubt that it is related to the lump unless the lump is painful and causing you to alter the way in which you walk.