Clinical features, surgical management and outcome of squamous and basal cell carcinoma in squamates and chelonians.

Background: Squamous cell carcinoma (SCC) is one of the most commonly diagnosed neoplastic disorders in reptiles. Recently, however, it has been demonstrated that basal cell carcinomas (BCCs) are frequently misclassified as SCCs. Several histological SCC and BCC variants have been characterised and their classification may allow the establishment of appropriate prognosis estimation and treatment approaches.

Hypothesis/objectives: To describe the clinical features and surgical outcomes of SCCs and BCCs diagnosed between 2010 and 2022 in reptiles.

Animals: Thirty-three captive reptiles (21 squamates and 12 chelonians).

Materials and methods: Detailed clinical history, including staging and surgical outcomes, were performed. Statistical analysis assessed significant factors using Prism (v8.2.1).

Results: While SCC was predominantly diagnosed in lizards, BCC was most commonly diagnosed in chelonians, and both neoplasms mainly occurred in adult to aged, male individuals. Although the gross pathological findings were highly comparable between SCC and BCC, considerable variation could be seen according to the primary location (oral, cutaneous or epidermis of the shell). Humane euthanasia or noncurative intent surgeries were performed in a minority of the cases. Curative intent surgeries were successful in 19 of 27 cases during a 1- to 7-year follow-up period, yet recurrence was seen in 8 cases. The results of this study allowed the identification of significant high-risk prognostic factors for SCC and BCC in reptiles.

Conclusions and clinical relevance: This study contributes to predicting the clinical behaviour and prognosis of distinct SCC and BCC histological variants, and selecting the most appropriate treatment protocol.