I would get it removed and a biopsy done. My lab had a pink, eraser-sized warty thing near his hind leg when he was 8. He was feeling fine but I discovered it when I was giving him a bath. I took him to the vet and she said it was up to me if we wanted to take a wait-and-see approach or investigate it more. I had her aspirate it and examine it thru the microscope there at the vet clinic ($110 for that). She thought the cells looked a little funny but couldn't be sure what it was so she recommended a removal and biopsy. We had it removed & it turned out to be a mast cell tumor stage I/II and were lucky that the tumor had not spread beyond the borders of its original site. My dog didn't require any chemo or meds. The bill for the removal and lab biopsy was $300. It's always good to know what you're dealing with b/c dogs who get a mast cell tumor once are more likely to get them again. Mast cell tumors account for up to 20% of skin tumors in dogs and they can be a very serious form of cancer. I'm not trying to scare you, just to let you know that something that I thought was nothing could've been a disaster for my dog and it was worth the $110 for my peace of mind. Good luck and best wishes to Sammi!