Bowenoid insitu carcinomas in two Devon Rex cats: evidence of unusually aggressive neoplasm behaviour in this breed and detection of papillomaviral gene expression in primary and metastatic lesions.

Abstract

Bowenoid insitu carcinomas (BISCs) are rare feline tumours that are thought to be caused by papillomavirus infection. Although they usually develop in old cats and are slowly progressive, multiple aggressive BISCs have been reported previously in a comparatively young Devon Rex cat. A 5-year-old (Case 1) and an 8-year-old (Case 2) Devon Rex cat developed numerous BISCs. Rapid progression resulted in euthanasia of both cats after 8months. A postmortem examination was possible only for Case 2 and revealed pulmonary metastases. Consensus PCR amplified only Felis catus papillomavirus type 2 (FcaPV-2) DNA from lesions from both cats. High FcaPV-2 copy number and FcaPV-2 E6/E7 gene expression were detected in a BISC from Case 1. High FcaPV-2 copy number and FcaPV-2 gene expression were detected in a BISC, a cutaneous squamous cell carcinoma (SCC) and the pulmonary metastases from Case 2, but not in two other cutaneous SCCs. The results provide additional evidence that BISCs develop at a younger age in Devon Rex cats and that BISCs in Devon Rex cats have a more aggressive behaviour than BISCs in other cat breeds. These unusual features should be considered when evaluating and treating skin disease in Devon Rex cats. The detection of FcaPV-2 gene expression in the lung neoplasms suggests a potential role of FcaPV-2 in the development of metastatic disease. However, the absence of FcaPV-2 gene expression in two cutaneous SCCs suggests that other factors could have also promoted cancer development.