KSH, I'd urge you to find a (different!) dermatologist and see about getting a cortisone shot like I had. If the bump keeps sinking back down between rides, it is probably not a cyst, as a cyst wall would be there all the time if it were. The dermatologist thought mine was just bad inflammation that was not healing on its own. The cortisone shot stung a little, but it helped immediately, and I am quite sure I could have ridden pain-free the very next day. It's definitely worth a try as your sore sounds an awful lot like mine, and since you're training for an IM and can't afford the downtime of a lancing or surgical removal. My gyn looked at it when it was more actively swollen and thought it could be a cyst requiring removal as well, but after a couple of months on the bike, it didn't retain its cyst-like qualities, just continued to be inflamed, irritated, and discolored.

BTW, I tried to heal mine myself for months -- nothing I tried worked. I got LOTS of blood out of it with a sterilized needle numerous times, which would flatten it out temporarily, but it would just come back right after my next ride.

GOOD LUCK!

Emily