About 2 months ago I noticed a large bump beside my daughter last molar as her molar was breaking through her gums. It was pinkish red and filled with fluid. To be honest, it truly freaked me out. Our family has a history of tumors in the mouth, so I took her to the dentist and found out it was just an eruption cyst. It causes her no discomfort and it goes relatively unnoticed (aside from her poking at it every now and then in curiosity ). The dentist said to give it some time and it will clear itself up. Now you should know that some, not a lot, but some do not clear up and will need to be surgically removed from the mouth...My little girl still has hers and it looks like that may be our only option left. However, I am not too keen on sedating a 2 year old so I will give it as much time as possible before we explore that avenue. Her cyst has since turned white over the top almost like a calice or dry dead skin so hopefully that is a good sign. Just go get it looked at and know that it is probably minor and her body will more than likely absorb and dispose of it. Don't worry & good luck.