Cutaneous squamous cell carcinoma, trichoblastoma and trichoepithelioma in dogs from a tropical region: potential implications of sun exposure

Authors: Vaz MAQ, Amaral CA, Leite JS, Batista BPS, Silva KVGC, Fonseca ABM, Ferreira AMR
Publication: Australian Veterinary Practitioner, Volume 54, Issue 1, pp 39-46, Mar 2024
Publisher: Australian Veterinary Association

Animal type: Dog
Article class: Clinical Article

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Abstract:

Background: Cutaneous tumors comprise 30% of all diagnosed tumors in dogs, potentially reflecting skin exposure to carcinogenic factors such as sunlight. Malignant, non-melanotic neoplasms, such as squamous cell carcinoma (SCC) represents about 15% of cutaneous tumors in dogs and often derive from pre-cancerous actinic lesions.

Objectives: This study aimed to describe occurrence and location of SCC, trichoblastoma and trichoepithelioma neoplasms and their relationship with coat colour in dogs residing in a high sunlight exposure region.

Animals: Fifty-four neoplastic nodules from 46 dogs were retrospectively selected from review of a pathology database.

Methods: Tumour type was grouped into malignant and benign categories, and further classified according to histopathological diagnosis, nodule location, age and animal coat colour. Data were evaluated using descriptive statistics tools, the chi-square test and Fisher’s exact test.

Results: Elderly, female and mixed-breed dogs were most commonly affected by epidermal and follicular evaluated tumors in this study. Moderately differentiated SCC located on the back of poorly pigmented dogs was the most frequently diagnosed neoplasm, followed by SCC located on the digit in animals with pigmented coats.

Conclusions: The results found in this study emphasize the importance of monitoring cutaneous lesions in dogs living in regions of high solar exposure, regardless of coat colour.

Keywords: squamous cell carcinoma, trichoblastoma, trichoepithelioma, dog, location, occurrence.

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