Yes, my two 3 year olds have both had one of these.
Sunny's was on his neck and we had it removed because the vet said it was too small to do a needle biopsy and we weren't sure what it was. Sophie had one on her leg which the vet did a needle biopsy of and said it was a histiocytoma. We left this one alone and it went away within about a month. Sunny now has another one on his ear. As this is in an awkward place for removal, we're hoping it will go away on its own.
I understand that they do normally disappear within 3 months but not always. I read somewhere that sometimes injecting them with steroids sometimes makes them go, so maybe you could ask your vet about that? I think that if it's growing rapidly I might be tempted to have it removed, as the larger it gets the more difficult it will be to remove it, but I know it's not easy choosing to put them through the risk of an anaesthetic for something relatively minor.
Let us know what you decide.