Tanaka has already taken Popo Chan to the vet.
It was diagnosed as an abcess, not a tumor, and she is on antibiotics for 2 wks. Bring her back if there's no improvement.
BTW- thanks for the pics Tanaka. It's helpful to be able to SEE these things. You always take the best pics to go along with the ailments and explain things so well.
Please do let us know how she is doing in a few days. Fingers n toes are getting cramped being crossed.