Digital Squamous Cell Carcinoma in Dogs

Abstract

Squamous cell carcinoma represents 47.4% of all malignant canine digital lesions, but despite its frequency, there are few published studies available. Pathology submission records of 154 cases and follow-up of 49 animals were analyzed. On the 49 cases, histological evaluation was performed of the differentiation degree, mitotic index, presence of emboli, and immunohistochemical expression of vimentin and E-cadherin. The mean (SD) age of affected animals was 10.2 (2.3) years; no sex predisposition was recorded. Beauceron and Briard were 2 new overrepresented breeds. Dark-haired animals comprised 97 of 105 (92%); 94 dogs of 125 (75.2%) belonged to large and giant breeds. The forelimb was affected twice more than the hind limb. Probable metastases were observed in 4 dogs; new tumor development was recorded in 11 of 49 (22.4%). Epidemiologic factors, histological grade, mitotic index, and expression of immunohistochemical markers seemed not to be related to the clinical outcome.Keywords digit, dog, epidemiology, histological grading, immunohistochemistry, prognostic factors, squamous cell carcinoma Malignant neoplastic processes account for 53.5% of all digital lesions in dogs, 15 and squamous cell carcinoma (SCC) is the most commonly diagnosed tumor. Affected animals have a mean age range between 7 and 9.8 years, depending on the study. 7,15 No sex predisposition has been described, and some breeds have been reported as overrepresented, particularly Rottweiler, Giant Schnauzer, Standard Poodle, and Dachshund. 4,11,12 Multiple digits can be affected, 3,4,12 and metastases have been recorded, with a prevalence ranging from 5% to 25% to local lymph nodes and lungs. 8,9,11,15 Although canine digital squamous cell carcinoma (CDSCC) is a frequent tumor, with an incidence of 47.4% of all digital malignant lesions, 15 clinical information is limited. The veterinary literature of digital SCC consists of 4 articles and 3 case reports, 5,[8][9][10][11][12]15 and thus epidemiological data may be considered incomplete, and no analyses of prognostic factors have been reported, to the best of our knowledge. CDSCC is histologically similar to SCC arising in other parts of the body, 3 but the application of histological grade criteria for cutaneous SCC does not predict the development of metastasis or multicentric tumors. 10The aims of our study were (1) to provide a better characterization of the epidemiology of this tumor, (2) A questionnaire about the follow-up and the development of multiple tumors was sent to all submitting veterinarians, and 49 replies were received. The answers to the questionnaire were obtained in May 2012, and thus the follow-up ranged from 23 to 28 months. Data concerning survival, the eventual cause of death, the presence or absence of metastasis, and new tumor development (occurrence, number of developed tumors, disease-free period) were analyzed.For the 49 cases in which follow-up data were available, 1 or more paraffin blocks derived from the same mass or multiple masses (5 cases) were obtai...

Retrospective study of canine cutaneous tumors in Japan, 2008–2017

“…Digital squamous cell carcinoma is known to have a distinct prognosis as compared to those on other skin regions [3]. Belluco et al demonstrated that canine digital squamous cell carcinoma rarely metastasized, but had a tendency for multicentric growth [3]. In the present study, all of the squamous cell carcinomas on limb extremities were solitary.…”

“…Similarly, previous study has reported a high occurrence of squamous cell carcinoma on the digit [16]. Digital squamous cell carcinoma is known to have a distinct prognosis as compared to those on other skin regions [3]. Belluco et al demonstrated that canine digital squamous cell carcinoma rarely metastasized, but had a tendency for multicentric growth [3].…”

Pigment Intensity in Dogs is Associated with a Copy Number Variant Upstream of KITLG

“…The risk allele for DSCC in dogs had >four copies of the CNV and homozygous animals were more likely to have DSCC [54]. Black-pigmented dogs are highly overrepresented for DSCC, as 92% of samples were from black-coated dogs [59]. However, there are breeds like the Flat-Coated Retrievers that have a high copy number, black hair coat, and are not predisposed to this type of tumor [59].…”

“…Black-pigmented dogs are highly overrepresented for DSCC, as 92% of samples were from black-coated dogs [59]. However, there are breeds like the Flat-Coated Retrievers that have a high copy number, black hair coat, and are not predisposed to this type of tumor [59]. It is possible that a high copy number at the KITLG CNV is another risk factor for breeds that are already more susceptible to this particular tumor type.…”

Evaluating the Histologic Grade of Digital Squamous Cell Carcinomas in Dogs with Dark and Light Haircoat—A Comparative Study of the Invasive Front and Tumor Cell Budding Systems

“…Nonetheless, given that there is no prognostic significance and often somewhat subjective assessment, many pathologists fail to characterize it. Broder's system was not included in this case since, similar to what other studies showed [11], there can be different grades of differentiation within the same tumor, making it hard when evaluating the sample. In this study, the goal was to compare two different adapted grading schemes to ascertain that there was a morphological disparity between light-and dark-colored animals with CDSCC and some kind of grading congruence between both systems.…”