Presentation, Diagnostic Imaging, and Clinical Outcome of Conventional Ameloblastoma in Dogs

Abstract

<jats:p> A noninductive tumor of odontogenic epithelium occurs within the tooth bearing regions of the jaw in dogs and fits the conventional definition of ameloblastoma, which is distinct from, and less common than, canine acanthomatous ameloblastoma. In order to clarify the clinical and radiological features of this uncommon odontogenic tumor in dogs, we performed a retrospective study of 20 dogs that were diagnosed between 2007 and 2015. Follow-up information was obtained for 17 of 20 dogs. The study group of dogs showed no apparent age, breed, or gender predilection. Conventional ameloblastoma is typically slow growing, well demarcated, and locally destructive. Tumors most commonly occurred as a mass or focal bony swelling within the maxilla (13/20) or mandible (7/20). Based on cases with available diagnostic imaging, as either dental radiographs or computed tomographic images, the tumors were usually intraosseous and caused mixed lytic/proliferative bone changes. Nevertheless, conventional ameloblastomas did not aggressively infiltrate adjacent tissues and recurrence was not observed within the study group, even in patients with narrow surgical margins or treatment by cyst enucleation. </jats:p>

Biological Behavior of Canine Acanthomatous Ameloblastoma Assessed With Computed Tomography and Histopathology: A Comparative Study

“…These 2 tumors differ in both histological pattern as well as biological behavior as elucidated by diagnostic imaging. 11 The current study reinforced the findings by of a previous study that computed tomography findings differ between CAA and conventional ameloblastoma. 11 Conventional ameloblastoma tends to have highly consistent imaging findings and are almost always consistent with a locular/cystic intraosseous mass, which does not tend to aggressively infiltrate adjacent tissue past the margin of the cyst.…”

“…The current study reinforced the findings by of a previous study that computed tomography findings differ between CAA and conventional ameloblastoma. 11 Conventional ameloblastoma tends to have highly consistent imaging findings and are almost always consistent with a locular/cystic intraosseous mass, which does not tend to aggressively infiltrate adjacent tissue past the margin of the cyst. 11 Within the present study, CAA was rarely associated with cystic structures (11%) and presented with equal frequency in a predominantly extraosseous or intraosseous location.…”

“…These 2 tumors differ in both histological pattern as well as biological behavior as elucidated by diagnostic imaging. 11…”

“…6 Canine acanthomatous ameloblastoma is a subtype of ameloblastoma 1,[7][8][9][10] that varies in histological pattern and biological behavior from the "conventional" ameloblastomas in dogs. 11 Potentially, desmoplastic ameloblastoma is a third subtype of ameloblastoma that has been reported in a dog. 1 The name CAA indicates the tumor's origin from odontogenic epithelium (ameloblastoma), its predominant histological pattern (acanthomatous), and conveys the idea that this tumor possesses different biological behavior than the human acanthomatous ameloblastoma (e.g.…”

“…the canine and human variants are not analogous). 1,[6][7][8][10][11][12][13] CAA appears to have variable biological behavior with some tumors presenting with slow growth and minimal bone loss while others grow rapidly and cause severe cancellous and cortical bone destruction. Armory et al previously demonstrated variable biological behavior of CAA on computed tomography, and suggested that CAA arising from a primarily intraosseous location behave more aggressively than their extraosseous counterparts.…”