Author(s): Murphy B, Bell C, Koehne A, Dubielzig RR. Mandibular odontoameloblastoma in a rat and a horse. J Vet Diagn Invest. 2017 Jul;29(4):536-540. doi: 10.1177/1040638717711996. Epub 2017 May 26. PMID 28545325
Journal: Journal Of Veterinary Diagnostic Investigation : Official Publication Of The American Association Of Veterinary Laboratory Diagnosticians, Inc, Volume 29, Issue 4, Jul 2017
Odontoameloblastoma (OA) is a mixed odontogenic tumor that is an ameloblastoma with concurrent histologic evidence of odontoma differentiation. As a mixed tumor, OA is a tripartite lesion comprised of neoplastic odontogenic epithelium, induced dental ectomesenchyme (dental pulp), and mineralized dental matrix. Although rare, OA represents a diagnostic conundrum, as it is histologically closely related to 2 other mixed odontogenic tumors: odontoma (complex and compound) and ameloblastic fibro-odontoma. Herein we describe an OA arising from the mandible of a 4-mo-old Fischer 344 rat that had been exposed in utero to the mutagen ENU (N-ethyl-N-nitrosourea), and a naturally occurring lesion in a 2-y-old Appaloosa horse. In order to satisfy the diagnostic criteria for this lesion, mineralized dental matrix in relationship to neoplastic odontogenic epithelium must be identifiable within the OA lesion. This group of odontogenic tumors is differentiated by the degree to which the dental matrix is organized and the relative proportions of pulp ectomesenchyme, odontogenic matrix, and odontogenic epithelium.