Theories.

Things that my lump might actually be:

1.  I ate a lot of vodka-soaked gummy bears at Penn State circa 2003.  Like a LOT.  Once my liver reached maximum absorption, one of them migrated through my bloodstream into my boob.

2.  I tripped and fell in a pile of gravel and gasoline at the Air Show when I was 7.  My parents were nowhere around (???) so my brother "fixed it up" for me.  He couldn't get all the gravel out of my knee so some of the pieces have been floating around in there for 20 years.  They finally settled in my boob.  Suspended in a glob of gasoline, of course.

When I Googled "bloody gravel knee," it came up with this.  So there you go.

3.  It's my missing tooth.  It's not in my mouth, which is why I still have a baby tooth.

4.  My mom cleans her entire house, including countertops and the kitchen table, exclusively with Clorox bleach and ammonia.  I have a previously-undiscovered type of really, really clean cancer.

Actual mom response: "Oh calm down.  The fumes are good for your sinuses."

5.  Since I'm actually a zombie, it's probably just scar tissue from where I was bit to begin with.

I actually look like this.  Not exaggerating.

Also:

You're welcome.