Abstract
Cutaneous squamous cell carcinoma (SCC) is a slow growing but locally invasive neoplasm, most commonly caused by prolonged exposure to ultraviolet (UV) radiation. Whilst SCC accounts for 15% of skin tumours in domesticated cats, cutaneous SCC in non-domesticated felids (apart from captive snow leopards) appears to be uncommon, with only three reports in the literature to date. In this report, a captive African lion (Panthera leo) presented with two ulcerative lesions on the nasal planum. Histopathology of the lesions revealed epidermal keratinocyte dysplasia and neoplastic basal- and supra-basal epithelial cells with dyskeratosis and evidence of basement membrane breaching and dermal invasion, consistent with a diagnosis of SCC. There was also evidence of laminar fibrosis and inflammation of the subjacent dermis suggesting that the SCC most likely resulted from UV-induced neoplastic transformation of the epidermal squamous epithelium following actinic keratosis. The lion was treated with hypofractionated radiation therapy and remained in remission until his death (euthanised 17 months later because of age-related chronic renal failure). This is the first report of cutaneous SCC in a lion with evidence of actinic damage and resolution after radiation therapy.
Highlights
Squamous cell carcinoma (SCC) is a malignant neoplasm arising from squamous epithelium
Squamous cell carcinomas account for 15% of skin tumours in domestic cats, with most feline cutaneous SCCs occurring on the head, often involving the pinna, eyelid and nasal planum (Miller et al 1991)
Factors contributing to the development of cutaneous SCC are prolonged exposure to ultraviolet (UV) radiation, lack of skin pigment and a sparse hair coat (Goldschmidt & Goldschmidt 2017) and infection by papilloma virus
Summary
Squamous cell carcinoma (SCC) is a malignant neoplasm arising from squamous epithelium. The present report describes a SCC on the nasal planum of an African lion that showed concomitant evidence of actinic damage in the surrounding area and successful treatment with radiation therapy. A 16-year-old intact male African lion from the Lory Park Zoo and Owl Sanctuary in Midrand, South Africa, who had lived at the property since he was a few days old, was presented to the Wildlife Clinic at Onderstepoort Veterinary Academic Hospital with a 2-month history of two round, well demarcated, laterally positioned, ulcerative lesions approximately 5 cm and 3 cm diameter and a midline elliptical lesion approximately 0.5 cm × 0.2 cm, on the nasal planum (Figure 1). Follow-up punch biopsies of the nasal planum 14 months later, because of the presence of ulcerating lesions at the site of the original SCC lesion, showed no evidence of neoplastic changes. There were no neoplastic lesions observed in any of the organs examined (kidney, stomach, spleen, heart, liver, pancreas, lymph node, lung, oesophagus and diaphragm)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
