question: 31 yr old male. Wrestler and jiu jitsu practitioner. Never had any significant health problems. I found a quarter sized lump on my inner thigh a couple inches south of my groin. It is firm, painless, slightly purple with a black dot on the top. You can move it under the skin. I've attempted to puncture it with a needle and squeezed it pretty hard to see if pus would come out. Only blood. I now have some fluid build up around the lump (what I get for being a DIY doctor, right?) It hasn't gotten any bigger. I started doing jiu jitsu again about 4 days a week for the last month. Only after I started jiu jitsu did this lump come up. Any ideas what it could be?