Dog wart

Help, my dog had a small wart which the vet removed about a month ago. It has now grown back way bigger and is growing rapidly! The vet got a sample and sent it to pathology but the results were inconclusive. They are now saying my only option is to get it cut out again and send it away to figure out what it is.   

Hello!  I have sever seen a sample report that simply says 'Im sorry but this was inconclusive.' They key may be in why the sample was inconclusive - what needs to be done differently next time, what the possibilities are and where to take it from here to get a more conclusive answer.   If the lab have been sent a full description of the wart and a sample, and have come back saying that they recommend that it is fully removed for diagnostic purposes, then there will be a good reason for this which hopefully they will be able to explain.   Best of luck.