title: Oral papillary squamous cell carcinoma in twelve dogs.
abstract: Papillary squamous cell carcinoma (PSCC) is a distinct histological subtype of oral squamous cell carcinoma (SCC), described in both dogs and man. In dogs, PSCC has long been considered a malignant oral tumour of very young animals, but it has recently been reported to occur in adult dogs as well. The aim of this study was to describe the major clinicopathological characteristics of canine oral PSCC (COPSCC). Twelve dogs diagnosed with COPSCC were included in this retrospective study (1990-2012). The majority (75%) of the dogs were >6 years of age (median age 9 years). All tumours were derived from the gingiva of dentate jaws, with 66.7% affecting the rostral aspects of the jaws. The gross appearance of the lesions varied, with one having an intraosseous component only. The majority (91.7%) of the tumours were advanced lesions (T2 and T3), but no local or distant metastases were noted. Microscopically, two patterns were seen: (1) invasion of bone forming a cup-shaped indentation in the bone or a deeply cavitating cyst within the bone (cavitating pattern), (2) histologically malignant growth, but lack of apparent bone invasion (non-cavitating pattern). The microscopical appearance corresponded to imaging findings in a majority of cases, with cavitating forms presenting with a cyst-like pattern of bone loss or an expansile mass on imaging and non-cavitating forms showing an infiltrative pattern of bone destruction on imaging. These features suggest two distinct biological behaviours of COPSCC.
authors.affiliation: Small Animal Clinic, Veterinary Faculty, University of Ljubljana, Slovenia; Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, USA.
authors.forename: A
authors.initials: A
authors.lastname: Nemec
authors.affiliation: Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, USA.
authors.forename: B G
authors.initials: BG
authors.lastname: Murphy
authors.affiliation: Departments of Orofacial Sciences, Pathology and Radiation Oncology, University of California, San Francisco, USA.
authors.forename: R C
authors.initials: RC
authors.lastname: Jordan
authors.affiliation: Departments of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, USA.
authors.forename: P H
authors.initials: PH
authors.lastname: Kass
authors.affiliation: Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, USA. Electronic address: fjverstraete@ucdavis.edu.
authors.forename: F J M
authors.initials: FJ
authors.lastname: Verstraete
mesh_terms: D000818:Animals; D002291:Carcinoma, Papillary / Q000473:pathology / Q000662:veterinary*; D002294:Carcinoma, Squamous Cell / Q000473:pathology / Q000662:veterinary*; D004283:Dog Diseases / Q000473:pathology*; D004285:Dogs; D005881:Gingiva / Q000473:pathology; D009062:Mouth Neoplasms / Q000473:pathology / Q000662:veterinary*; D012189:Retrospective Studies
keywords: dog; oral papillary squamous cell carcinoma