If only blood came out, its probably malignant and infiltrating. I would keep her alive as long as she seems comfortable, but once you notice it becoming necrotic, cull her. So sorry, I was really hoping it was filled with pus. Come to think of it, it could be a sinus infection gone wild. I know that coryza can cause growths, but I'm not sure of the other symptoms of coryza. If she has mucous, it could be sinuses, but once a sinus infection is that bad, its pretty much over.