The vet said it was just a cyst. He said he wouldn't remove it now since he doesn't need to do anything else. However, if it keeps growing at the current rate (nothing to 1 cm in 2 months) I'm assuming we'll have to have it removed at some point.
I'm relieved. He also calmed my fears about the rabbies vaccine causing cancer.
Also, I'm in a good mood due to an olympic outcome but I don't want to spoil anything for those you will watch later.