I used to have a lump at the base (palm side) if my middle finger. it woudl occasionally get tender but usually had not effect on me.
Come to find out my balls were all drilled with a span ~1/4 inch too long and I was actually damaging the tendon.
years ago I dislocated my thumb playing softball... 1.5 years later after it still being stiff and having a lump I got it looked at by a doctor come to find out I had actually broken it and the broken piece of bone healed out of position and had carved out over 50% of the cartilage in the knuckle....

TLDR: get it looked at. you may have damaged something