Feline cutaneous fibropapillomas: Clinicopathologic findings and association with papillomavirus infection

Twenty-three feline cutaneous fibropapillomas with histologic features simi lar to equine sarcoids were diagnosed. They were characterized by dermal fi broblastic proliferation with overlying, often ulcerated hyperplastic epide rmis. Electron microscopic findings supported the fibroblastic nature of th e neoplastic cells. The 23 tumors came from 20 cats and were submitted from veterinary clinics in Wisconsin and Minnesota. These tumors occurred most commonly in young cats and were found primarily on the head, neck, and digi ts. Fifteen of the 17 cats fur which breed was reported were domestic short hair cats. In 11/20 cases, there was confirmed exposure to cattle. Local re currence of the tumor following surgical excision was reported in 7 of the 18 cats for which follow-up information was available. Metastasis was not d ocumented in any of the cases. Two of the 19 tumors tested by polymerase ch ain reaction (PCR) had no amplifiable DNA. The remaining 17 were positive f or papillomavirus by PCR. No papillomavirus DNA was detected in three other feline skin tumors (cutaneous mast cell tumor, malignant lymphoma, and fib rosarcoma) that served as controls. This is the first report of detection o f papillomavirus in feline turners that have clinicopathologic features sim ilar to equine sarcoids.