Montana Pet & Oral Surgery Tony M. Woodward, DVM, AVDC • (406) 599-47849 • [email protected]

Update on CAA (aka-Acanthomatous ) April 2011 A recent JAVMA article by Fiani, et al. entitled “Clinicopathologic characterization of Remember: odontogenic tumors and focal fibrous hyperplasia in dogs: 152 cases (1995-2005)” shed Although CAA is a benign tumor, 0.5 to 1 cm margins from visible and some interesting light on some of the more common “benign” oral tumors. The study radiographic margins are required was a retrospective study from the Veterinary Medical Teaching Hospital at UC Davis, for successful treatment. seen for evaluation of oral tumors that were diagnosed as either: canine acanthomatous ameloblastoma (CAA)—what we have called acanthomatous epulis in the past; Dental Training Classes: peripheral odontogenic (POF)— We are now booking classes what we have called a fibromatous epulis in for August 2011 in Colorado. A few spaces remain for the August 18/19 the past; and focal fibrous hyperplasia (FFH) Level I and Level II classes. For —what we have called gingival hyperplasia more information, call Trish in the past. The study reviewed the breed, at 719-536-9949. Complete age, reproductive status, and location of the information about class format, costs and content is available at: lesion in the oral cavity of each case. Other www.vetdentalclasses.com. odontogenic tumors such as the odontoma and the amyloid producing odontogenic Upcoming Montana CE: tumor (APOT) were not evaluated due to their Montana Pet Dentistry and Oral relative very low incidence in dogs. Surgery will be presenting evening Figure 1: Pre-operative appearance of the mass. lectures around the state of The article does try to clarify some Montana in conjunction with Pfizer terminology. The term “epulis” is simply a and MWI. The first two dinner descriptive term of any gingival enlargement meetings will be held in Billings on Tuesday May 10th and Bozeman on and does not provide any information Wednesday May 11th. Dinner will with regard to the histologic appearance or be served at 6 PM and the lectures pathologic nature. The POF is a benign will run from 6:30 to 8 PM. Topics neoplastic process of odontogenic origin with will include “Blowing the Top Off Your Dental Department” and histologic appearance that is different than “Dental Pathology You See Every the FFH which is non-neoplastic, reactive Day”. We will apply for CE credit inflammatory tissue that enlarges in response for these meetings. Your Pfizer and/ to chronic irritation. or MWI representative will be in contact soon. Additional meetings The average age at detection was approximately will be scheduled soon in other Figure 2: Post-operative appearance. 9 years for all groups and no significant sex areas of Montana. These evening predilection was noted for any. The most lectures will be followed by a full- common of these was the CAA (45%), the POF (31%), and the FFH (16%). The day lecture and wet lab this fall in Bozeman. remaining 8% were “other” odontogenic tumors not classified in the study. For the CAA, the breeds most predisposed (in order) were the Golden Retriever, Akitas, Cocker Spaniel, and Shetland Sheepdog. This is contradictory to another study of canine epulides by Yoshida et al in 1999, who reported the Shetland Sheepdog to be much more predisposed than any other breed. The most common location of the CAA was found to be on the rostral . In general, the CAA is technically a benign tumor in the respect that this tumor has never been reported to metastasize, but they are considered to be locally invasive into surrounding and therefore treatment dictates excision of the mass with at least 0.5cm margins of clinically and radiographically normal tissue. Clean surgical margins equates to an excellent prognosis with a very low Tony M. Woodward, DVM, AVDC, has practiced for over incidence of recurrence (less than 2%). These tumors are also radiosensitive and those 28 years, is past president of the Colorado that cannot be resected surgically should respond well to radiation therapy. One Veterinary Medical Association, and is board certified in veterinary dentistry. (continued on back) Tony M. Woodward, DVM, AVDC • Montana Pet Dentistry and Oral Surgery • (409) 599-4789 • email: [email protected] • www.montanapetdental.com Montana Pet Dentistry & Oral Surgery Case Study — Update on CAA (aka-Acanthomatous Epulis) recent study by Kelly et al reported in 2010 also found good results with intralesional bleomycin injections. The POF and FFH behave similarly. There was no real breed predilection for either, although the Golden Retriever was slightly overrepresented compared to what was expected in the POF. Both were more commonly found in the rostral . The treatment of either is similar, excision and contour to a level of normal gingival attachment. Recurrence is common, and if POF is the tumor involved, in some rare instances, extraction of the involved with alveoloplasty can prevent recurrence. In cases of POF, removal of the inciting cause, such as plaque and can be of benefit. The one question I have regarding the study is the relative high incidence of CAA in comparison to what would seem to be more common lesions such as the POF Figure 3: Pre-operative radiograph. and FFH. The author acknowledges this discrepancy in the discussion and suspects the skew in these numbers is due to the fact that the study was conducted on cases referred to the teaching hospital and that many of the more benign lesions such as the POF/FFH are not the type of cases that are referred for treatment. I also would have suspected the Boxer to be over-represented in the POF and FFH cases. In any case, this study is helpful to the general practitioner to help classify very common lesions. The pictures illustrate a typical case. This is a young (1 year old) F/S Golden Retriever with a mass at the left rostral mandibular gingiva around #304, previously biopsied as a canine acanthomatous ameloblastoma (CAA). The mass, including the surrounding alveolar bone and tooth roots was removed with 5-10mm margins. Note we were able to preserve the symphyseal attachment at it’s caudal extent. The en bloc Figure 4: Post-operative radiograph. Note that the mass margins were assessed histologically and found to be clean. This patient has an caudal extent of the mandibular symphysis could

excellent prognosis. be spared, providing stable occlusion.

Update on CAA (aka-Acanthomatous Epulis) (aka-Acanthomatous CAA on Update Study— Case

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Tony M. Woodward, DVM, AVDC DVM, Woodward, M. Tony

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