Ameloblastic fibro-odontoma associated with a retained molar in an Oldenburg mare

• Published in: Journal of veterinary diagnostic investigation Vol. 22; no. 6; pp. 987 - 990
• Main Authors: Knowles, Susan, Blas-Machado, Uriel, Butler, Abigail M, Gomez-Ibanez, Sara E, Lowder, Michael Q, Fayrer-Hosken, Richard A
• Format: Journal Article
• Language: English
• Published: United States 01.11.2010
• Subjects: Animals; clinical examination; epithelium; Female; Horse Diseases - pathology; Horses; Mandibular Neoplasms - diagnosis; Mandibular Neoplasms - pathology; Mandibular Neoplasms - veterinary; mares; mineralization; Molar; necropsy; Odontogenic Tumors - pathology; Odontogenic Tumors - veterinary; Odontoma - diagnosis; Odontoma - pathology; Odontoma - veterinary; radiography; tooth enamel; weight loss
• ISSN: 1040-6387; 1943-4936
• DOI: 10.1177/104063871002200625

An 11-year-old Oldenburg mare presented with a 3-month history of weight loss and swelling of the posterior right mandible. Physical examination and radiographs showed a soft-tissue mass in the right mandible with foci of mineralization, periosteal proliferation, and a retained molar. The tumor increased in size over several weeks, and the mare was euthanized. On necropsy, a 24 cm x 15 cm x 15 cm firm, white mass had obliterated the posterior right mandible. The mass was multinodular with discrete clusters of blood-filled cystic spaces. Histologically, the mass was composed of neoplastic odontogenic epithelium and pulpal mesenchyme with an accumulation of eosinophilic material resembling dentin or enamel. Microscopic and immunohistochemical staining features of the neoplasm were most consistent with an ameloblastic fibro-odontoma.