CycleFish: Good luck with the surgery!

Oak leaf: your story sounds exactly like mine! I have a couple of asphalt tattoos - one on my knee, one on my elbow - from a fall on my bike on a crushed asphalt road when I was 9. Like you, I am 51 (or will be on St Pat's Day.). Guess the wounds weren't cleaned out well, and the black rock just healed under the skin.