I have never seen the type of red lesion on the tongue as your hen has. I would suspect a bite or peck from another chicken, but there could be some sort of cancer. Did you get human oral canker medicine, such as campho phenique, or did you get bird canker medicine such as Fish Zole. That does not look like bird canker, which is a protozoan infection. Those and wet fowl pox cause yellow thick caseous material in the beak.