I have something similar on my side, I can't remember what excatly he said it was, but that it was likely just a buildup of something (wish i could remember now what he said) and not to worry about it. It has never gotten any bigger and i usually don't notice it. This may have nothing in common with what you have going on, just throwing it out there. If it doesn't change color or form some odd shape, it's likely not a big deal.