Canine papillomatosis: a retrospective study of 24 cases (2001-2011) and immunohistochemical characterization

Abstract

A retrospective study of 24 cases of papillomas in dogs was performed from January 2001 to March 2011. Additionally, immunohistochemistry (IHC) was used to characterize and evaluate the samples. We found that disease was observed more in mixed breed dogs, ages ranging from 6 months to 10 years (mean 3.1 years), and there was no gender predilection. The main lesion sites were the skin (75%), lips (16.7%), and eyelids (8.3%). Upon histological evaluation, we observed papillary exophytic proliferation of squamous epithelium and papillary endophytic proliferation (inverted) in 87.5% and 12.5% of cases, respectively. The tumors were characterized by spinous layer hyperplasia (87.5%) with koilocytes (70.8%) and intranuclear pale basophilic inclusions bodies (8.3%), prominent granular layer with large amounts of keratohyalin granules (95.8%), and hyperkeratosis in the stratum corneum (100%). Positive immunostaining for Papillomavirus was found in 83.3% of cases, which were distributed between the granular layer and the stratum corneum. These findings indicate the following: that papillomas in dogs are caused by Papillomavirus, the viral cytopathic effect induces epithelial lesions, viral particles are found inside the cell nuclei, and inclusions bodies are rare.

Malignant Transformation of a Canine Papillomavirus Type 1-Induced Persistent Oral Papilloma in a 3-Year-Old Dog

“…39,[65][66][67][68] Table 3 summarizes different diagnostic tests used to confirm infections of CPV. 2,5,8,22,[28][29][30][31]36,37,39,64,66,68,69,70,71 Veterinarians must be aware that CPV has the potential to induce latent infections. One study demonstrated CPV DNA in 23% of oral samples collected from healthy dogs.…”

“…Koilocyte and inclusion bodies. 36,39,64 Histopathology is the most common test for diagnostic canine oral papillomavirus (COVP) infections. 28 Evaluation of lymphocytic infiltration is possible by this method, facilitating the differentiation between regressive and nonregressive lesions.…”

“…5 Limited access as this test is only performed in specialized laboratories. IHC FFPE/BE or FFT Detection of mAB that target whole COPV 64 or the L1 or L2 capsid proteins. 39 Intense intranuclear antigen immunostaining of keratinized squamous cells confirms positive results.…”

Hyperproliferative action of bovine papillomavirus: genetic and histopathological aspects

“…Koilocytosis is commonly identified histopathological analyses of papillomas in different organisms, including canines (Bianchi et al, 2012) and humans (Betiol et al, 2012;Rogovskyy et al, 2012). Koilocytes are degenerated keratinocytes that are destined for cell death or epithelium release.…”

Oral Papillomatosis in a Dog: Surgical Management and Histopathological Findings

“…The Papillomavirus is a DNA virus that has special affinity towards the cutaneous squamous or mucosal epithelium (Gross et al, 2008). Canine papillomatosis is commonly seen in mixed-breed dogs of age in between 6 months to 10 years, and majority of the lesions are seen in skin followed by lips (Bianchi et al, 2012). Studies conducted by Sundberg et al, 1994 have reported that dogs with immunosuppressive disorders are highly predisposed to canine papillomatosis.…”