Odontoameloblastoma with extensive chondroid matrix deposition in a guinea pig. (September 2018)

• Record Type: Journal Article
• Authors: Wong, Hannah E.; Hedley, Joanna; Stapleton, Nadene; Murphy, Brian; Priestnall, Simon L.
• Is Part Of: Journal of veterinary diagnostic investigation. Volume 30:Number 5(2018:Sep.)
• Page Start: 793
• Page End: 797
• Publication Date: 2018-09
• Subjects: Chondroid -- guinea pigs -- odontoameloblastoma -- odontogenic mixed tumor; Veterinary medicine -- Diagnosis -- Periodicals; 636.0896075
• DOI: 10.1177/1040638718794784
• Languages: English
• ISSNs: 1040-6387

Abstract

Odontoameloblastomas (previously incorporated within ameloblastic odontomas) are matrix-producing odontogenic mixed tumors and are closely related in histologic appearance to the 2 other types of matrix-producing odontogenic mixed tumors: odontomas and ameloblastic fibro-odontomas. The presence or absence of intralesional, induced non-neoplastic tissue must be accounted for in the diagnosis. Herein we describe a naturally occurring odontoameloblastoma with extensive chondroid cementum deposition in a guinea pig ( Cavia porcellus ). Microscopically, the mass featured palisading neoplastic odontogenic epithelium closely apposed to ribbons and rings of a pink dental matrix (dentinoid), alongside extensive sheets and aggregates of chondroid cementum. The final diagnosis was an odontoameloblastoma given the abundance of odontogenic epithelium in association with dentinoid but a paucity of pulp ectomesenchyme. Chondroid cementum is an expected anatomical feature of cavies, and its presence within the odontoameloblastoma was interpreted as a response of the ectomesenchyme of the dental follicle to the described neoplasm. Our case illustrates the inductive capabilities of odontoameloblastomas while highlighting species-specific anatomy that has resulted in a histologic appearance unique to cavies and provides imaging and histologic data to aid diagnosis of these challenging lesions.