Clinical, Histologic, and Immunohistochemical Analyses of Feline Squamous Cell Carcinoma In Situ

Abstract

Actinic keratosis (AK) and Bowenoid in situ carcinoma (BISC) are two distinct forms of in situ squamous cell carcinoma in felines. They usually occur on different locations and present with specific clinical and histologic features. However, in some cases, these diseases cannot be distinguished either clinically or histopathologically. The aim of the present study was to determine the accuracy of diagnosis based on clinical or histologic criteria alone, and whether immunohistochemistry for papillomavirus or p53 can improve the accuracy of diagnosis. A series of in situ squamous cell carcinoma cases (n = 45) were selected according to their location and initial histologic classification and subsequently classified as AK (n = 22) or BISC (n = 23) according to the clinical criteria and were reevaluated histologically by 2 dermatopathologists. All BISC cases and most of the AK cases (n = 15) were confirmed histologically. In 7 cases clinically classified as AK, this diagnosis was not unanimously confirmed histologically because of the presence of overlapping features. P53 immunoreactivity was observed in 11/14 (79%) confirmed AK cases and in 4/22 (18%) BISC cases, while papillomavirus antigen was not detected in any confirmed AK case but was detected in 11/23 (48%) BISC cases. It was concluded that BISC can usually be reliably diagnosed histologically. The histologic diagnosis of lesions clinically suggestive of AK might sometimes be difficult. Results of immunohistochemistry for p53 and papillomavirus antigen were supportive for a role of sun exposure and papillomavirus in the pathogenesis of AK and BISC, respectively.

Actinic keratosis in dogs

“…Entretanto, o mesmo não ocorre em medicina veterinária, apesar da elevada incidência destas doenças (ALMEIDA et al, 2001;PRONOVOST et al, 2004;TAMMENHAIN et al, 2008;FAVROT et al, 2009). POGGIANI, S.S.C.…”

Multicentric Squamous Cell Carcinoma In Situ Associated With Papillomavirus in a Ferret

“…However, viral inclusion bodies within keratinocytes, as described in this ferret, have not been identified in the BISC lesions in cats. 6,7,20 Given the general species specificity of papillomaviruses, 24,28 this difference suggests that a different papillomavirus could be associated with the lesions in this ferret. Some reports described intracytoplasmic pseudoinclusions in BISC in cats, 28,30 which consist of finely granular to fibrillar electron-dense material of aberrant intermediate filament assembly.…”

“…7 In this species, the lesions are often multifocal crusted plaques histologically characterized by irregular epidermal hyperplasia and dysplasia, which can progress to invasive squamous cell carcinoma. 6,17 Papillomavirus has been identified in these BISCs. 6,9,15,17,18,30 The purpose of this report is to describe the features of a case of multicentric squamous cell carcinoma in situ in a ferret associated with papillomavirus.…”

“…7 In cats, BISC has been associated with papillomavirus. 6,9,10,17,18,20 Papillomavirus is also implicated in the development of other feline skin neoplasms, such as cutaneous fibropapillomas (also called feline sarcoid), 26 oral papillomas, 28 cutaneous viral papillomas; 15,28,30 and invasive squamous cell carcinoma. 16,20,28 The lesions of BISC in cats are multicentric, similar to the distribution of the lesions observed in the present ferret.…”

“…16,20,28 The lesions of BISC in cats are multicentric, similar to the distribution of the lesions observed in the present ferret. 6,7,30 Histologically, the lesions are similar and characterized by plaques of irregular epidermal hyperplasia and dysplasia. However, viral inclusion bodies within keratinocytes, as described in this ferret, have not been identified in the BISC lesions in cats.…”