It might be a spot, I had one once, which is odd because I rarely get spots anywhere. DON'T TRY AND SQUEEZE IT! If you're worried go and see a doctor, s/he will obviously need to look at it, but I don't know what he'll do about it because obviously that'll depend on what he thinks the problem is.
I'm sure it's not something bad, it's not like cancer or anything if it's just on the surface.
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It's a small world and it smells funny
I'd buy another if it wasnt for the money