My Chloe had one, and the vet told us it was perfectly normal and not to worry about anything.
Read here:
http://www.midcapeanimalhospital.com/showpracfaq.cfm?FAQID=135&Private=0
Our English Mastiff, Condi, had one when she was a pup. The vet took care of it when we had her fixed at 6-months old.
No complications or negatives that I can recall from 5wks to 6-mo's, when she had it taken care of (I say "taken care of" and not 'removed', because I'm not exactly sure what they do to get rid of it).
I'm assuming this is a puppy, right? When you take him/her in for shots, point it out to the vet and let them give you guidance, but I'm thinking it's not a huge deal.