My sympathies--I had one similar taken off my shoulderblade a few years ago. It left a nice scar. I tell everyone "It was nothing: I was stabbed in the back...at work..."
I had a course of around a dozen freckles removed from the midline of my back in a nice "shotgun spray" pattern from right to left. I often tell people "Oh, I got stabbed in the prison showers" for laughs.
LOL. That reminds me of something I heard on SNL, back when Vanilla Ice was in the spotlight:
"I told the world I was stabbed in the butt, but it was a toilet paper cut!"
Don't know why that stuck. Probably just really funny to a 12 year old.