Mandibular odontoameloblastoma in a rat and a horse.
Abstract: 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.
Publication Date: 2017-05-26 PubMed ID: 28545325DOI: 10.1177/1040638717711996Google Scholar: Lookup
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Summary
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The study reports on a rare type of mixed odontogenic tumor called odontoameloblastoma (OA), describing its manifestation in a rat and a horse.
Introduction to Odontoameloblastoma (OA)
- Odontoameloblastoma (OA) is a rare type of tumor that originates from the cells that form teeth (odontogenic epithelium).
- As a mixed tumor, OA consists of three parts: neoplastic odontogenic epithelium, dental pulp (also known as dental ectomesenchyme), and a mineralized dental matrix.
- Understanding the difference between this type of tumor and similar odontogenic tumors presents a challenge because they share several histological characteristics. These similar tumors include odontoma (which could be complex or compound) and ameloblastic fibro-odontoma.
Case Studies Presented
- The researchers discuss two cases — one involving a four-month-old Fischer 344 rat and the other a two-year-old Appaloosa horse.
- In the case of the rat, it was exposed to a mutagen (substance that causes genetic mutation) called ENU (N-ethyl-N-nitrosourea) while in the womb, which the researchers suggest may have resulted in the development of the OA.
- On the other hand, the horse’s condition occurred naturally, without notable exposure to any particular mutagen.
Diagnostic Criteria and Differentiation
- The diagnosis of this tumor type involves identifying the presence of the mineralized dental matrix in relation to the neoplastic odontogenic epithelium within the OA lesion. That is, there is need for evidence of teeth-like structure in the tumor.
- For differentiation from other similar tumors, evaluation of the dental matrix organization and the relative proportions of the pulp ectomesenchyme, odontogenic matrix, and odontogenic epithelium is performed. The differences in these aspects help discern the type of odontogenic tumor.
Cite This Article
APA
Murphy B, Bell C, Koehne A, Dubielzig RR.
(2017).
Mandibular odontoameloblastoma in a rat and a horse.
J Vet Diagn Invest, 29(4), 536-540.
https://doi.org/10.1177/1040638717711996 Publication
Researcher Affiliations
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, CA (Murphy).
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI (Bell, Dubielzig).
- Department of Comparative Medicine, School of Medicine, Stanford University, Stanford, CA (Koehne).
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, CA (Murphy).
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI (Bell, Dubielzig).
- Department of Comparative Medicine, School of Medicine, Stanford University, Stanford, CA (Koehne).
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, CA (Murphy).
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI (Bell, Dubielzig).
- Department of Comparative Medicine, School of Medicine, Stanford University, Stanford, CA (Koehne).
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, CA (Murphy).
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI (Bell, Dubielzig).
- Department of Comparative Medicine, School of Medicine, Stanford University, Stanford, CA (Koehne).
MeSH Terms
- Ameloblastoma / diagnosis
- Ameloblastoma / pathology
- Ameloblastoma / veterinary
- Animals
- Horse Diseases / diagnosis
- Horse Diseases / pathology
- Horses
- Male
- Mandibular Neoplasms / diagnosis
- Mandibular Neoplasms / pathology
- Mandibular Neoplasms / veterinary
- Odontogenic Tumors / diagnosis
- Odontogenic Tumors / pathology
- Odontogenic Tumors / veterinary
- Odontoma / diagnosis
- Odontoma / pathology
- Odontoma / veterinary
- Rats
- Rodent Diseases / diagnosis
- Rodent Diseases / pathology
Citations
This article has been cited 4 times.- Schreeg ME, Radkin M, Haugland J, Murphy BG, Rushton S, Linder KE. Ameloblastic carcinoma in horses: case report and literature review. J Vet Diagn Invest 2022 May;34(3):528-534.
- Hartung S, Köhler K, Herden C, Henrich M. Differential diagnosis for a mandibular mass - a rare case of an odontoameloblastoma in a red deer (Cervus elaphus elaphus). BMC Vet Res 2021 Jan 28;17(1):55.
- Huang P, Bell C, Wallace V, Murphy BG. Mixed odontogenic tumors in four young dogs: ameloblastic fibroma and ameloblastic fibro-odontoma. J Vet Diagn Invest 2019 Jan;31(1):98-102.
- Wong HE, Hedley J, Stapleton N, Murphy B, Priestnall SL. Odontoameloblastoma with extensive chondroid matrix deposition in a guinea pig. J Vet Diagn Invest 2018 Sep;30(5):793-797.
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