title: Malignant ameloblastic fibro-odontoma in a dog.
abstract: An 11-year-old male Collie was presented with a swelling of the face caused by tumor masses arising from the gingiva. Postmortem examination revealed metastases to the lymph nodes, lung, liver, and orbital cavity. Histologically, the tumor represented a combination of fibrosarcomatous proliferation, pulpal mesenchyme, and undifferentiated odontogenic epithelium, with a follicular or plexiform growth pattern. In addition, the follicular areas of the tumor showed a biphasic character, and there were numerous apoptotic cells in plexiform areas. Furthermore, acidophilic material resembling dysplastic dentine or enamel matrix was observed in the metastatic lesion in the lung. Based on the histological characters, the present case was diagnosed as malignant ameloblastic fibro-odontoma. This study is the first known description of a possible malignant ameloblastic fibro-odontoma in a dog with metastasis to distant organs.
authors.affiliation: Department of Veterinary Pathology, Faculty of Veterinary Medicine and Animal Sciences, Kitasato University, 35-1 Higashi-23-bancho, Towada, Aomori 034-8628, Japan. hiroyasu@vmas.kitasato-u.ac.jp.
authors.forename: H
authors.initials: H
authors.lastname: Ueki
authors.forename: A
authors.initials: A
authors.lastname: Sumi
authors.forename: H
authors.initials: H
authors.lastname: Takaishi
authors.forename: H
authors.initials: H
authors.lastname: Ito
authors.forename: T
authors.initials: T
authors.lastname: Oyamada
authors.forename: H
authors.initials: H
authors.lastname: Yoshikawa
mesh_terms: D000818:Animals; D002863:Chromogenic Compounds; D004283:Dog Diseases / Q000175:diagnosis / Q000473:pathology*; D004285:Dogs; D005887:Gingival Neoplasms / Q000473:pathology / Q000662:veterinary*; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D007633:Keratins; D008175:Lung Neoplasms / Q000473:pathology / Q000556:secondary / Q000662:veterinary*; D009810:Odontoma / Q000473:pathology / Q000662:veterinary*
chemical_list: D002863:Chromogenic Compounds; D007633:Keratins