Hi Debra, First of all, let me offer my deepest condolences to you and yours..... fibrosarcomas are terrible things... In 2001 our ferret , Bruiser had one removed from his face....( the face is a particularly hard place to treat) the bad part of these particular tumors is that even if you remove every bit of it...there are still millions of cells that remain and will grow again, rapidly. We had this tumor debulked every 3 months only for it to return again and every time with a vengeance worse than before. Dr Bruce Williams worked with our Vet on this and included it in his chapter in Rabbits Rodents and Ferrets, the book most exotic vets use. If your Vet doesn't have one please buy them a copy. It makes me sick to have to tell you this but the prognosis is poor... We were the first ones to have it cryoed thinking somehow this would destroy it....no. We put Bruiser through hell....we operated at least 4 times in a matter of months, it only returned.... You may have more time because with it in the leg as there is always radiation and even amputation. So you will have choices. I swore if we were ever presented with this again, we would make our ferret comfortable and enjoy the quality of his life as long as we could and then we would say Goodbye......... Never again would we put him through the painful extra measures that only gave him a couple months at best. I'm so very sorry that you have been faced with this. It won't be an easy decision either way.....feel free to mail me, please. Sending tons of hugs and love, Tara [Posted in FML 6131]