This is most likely a mucocele, a very common oral occurrence. There are indeed thousands of little openings in the soft tissues of your mouth each which secrete moisture to keep everything wet. When one of these becomes clogged up (for many different and benign reasons) a mucocele forms. Mine occur over and over again in the same spot for a week or so and then finally things clean out and it goes away. They can also occur from minor trauma to the soft tissue, and the most common place for this to occur is the inside of the lower lip and the inside of the cheeks. They are usually almost perfectly round, filled with clear fluid, and the overlying layer of tissue is almost clear. The tender wall of these little cysts eventually breaks, usually during eating, and the fluid flows out, and the cyst heals by secondary intent (on its own)

Brian, stage 4 oral cancer survivor. OCF Founder and Director. The first responsibility of a leader is to define reality. The last is to say thank you. In between, the leader is a servant.