It's hard to see as the picture is too far away to get a good look. Does it look like it has liquid inside? How large is it? My cat, Trevor, has a liquid bump that comes and goes on his face and the vet said it is a cyst. He said that if he drains it, it would most likely coming right back. (I even poked it with a pin myself, sterilized of course, and got some fluid out.) It was back in no time. We have chosen to leave it alone and just ignore with it when it is full again. Trevor's is about the size of a pea when full of liquid.