Similar to a "Goose Egg", which occurs when a person is hit in the head and a swollen lump appears. The one difference is that this Goose Egg occurs in the genital area rather than the head, forehead, etc.
Person 1: Dude I just got done filming my own Jackass show to put on youtube
Person 2: Really? How'd it go?
Person 1: It was funny, but I ended up getting hit in the balls with a teeter-totter. Now I have dick knuckles, great.
When your cock torques off to the left (or right), resembling a semi-ripe banana when erect, and a partially hooked finger when flaccid. Common in angry short men, orangutans, and intellectual pygmies.