The vet just called with the histopathology on the boys.
Rufus - his growth turned out to be a papilloma which has been irritated by trauma.
Brutus - his growth is a malignant low grade hemangiosarcoma caused from solar exposure. The pathology report says it may likely come back locally to his nicotating membrane but it it has a low rate of metastasis. His prognosis is favorable and they were able to excise the tumor completely. This is a particularly nasty, aggressive cancer and the prognosis is almost always poor. He however had it in the most ideal location (orignianated in the nicotating membrane and not a metastasis from visceral hemangiosarcoma) possible, we caught it very quickly and the vet it happy with the prognosis from the lab. So, although it is awful, its awesome news.