title: Extraskeletal fibroblastic osteosarcoma in a rabbit (Oryctolagus cuniculus).
abstract: A seven-year-old rabbit was presented with a non-painful mass in the right upper lip. Tissue samples from the mass at three different stages of the disease process were diagnosed sequentially as an osteogenic sarcoma, a fibroblastic tumour with rudimentary osteoid formation and, lastly, a fibrosarcoma. No bone involvement or metastatic disease was found. The final diagnosis was of an extraskeletal fibroblastic osteosarcoma, which is, to the authors' knowledge, the first reported such case in a domestic rabbit. Without the first two tissue samples, an incorrect diagnosis would have been reached; therefore, this disease may be underrepresented in the literature.
authors.affiliation: Churchview Veterinary Surgery, Moreton, Wirral.
authors.forename: H
authors.initials: H
authors.lastname: Renfrew
authors.forename: J R
authors.initials: JR
authors.lastname: Rest
authors.forename: A R
authors.initials: AR
authors.lastname: Holden
mesh_terms: D000818:Animals; D003937:Diagnosis, Differential; D017809:Fatal Outcome; D005354:Fibrosarcoma / Q000473:pathology / Q000601:surgery / Q000662:veterinary; D008048:Lip Neoplasms / Q000473:pathology / Q000601:surgery / Q000662:veterinary*; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000473:pathology / Q000601:surgery / Q000662:veterinary*; D012516:Osteosarcoma / Q000473:pathology / Q000601:surgery / Q000662:veterinary*; D011379:Prognosis; D011817:Rabbits