Sebaceous cell differentiation in a canine oral papilloma

Upregulated MYC expression and p53 mutations may contribute to the oncogenesis of canine Meibomian gland carcinomas

Sebaceous carcinomas of the human ocular adnexa commonly exhibit pagetoid spread, mutations in tumor-suppressor genes, and protooncogene copy number gain. Sebaceous carcinomas are rarely reported in other species, and while the Meibomian gland (MG) represents the most common ocular adnexal structure of the canine eyelid to develop neoplasia, most are clinically and histologically benign. The objective of this study was to compare molecular features of canine MG carcinomas and adenomas. Two retrospectively identified MG carcinomas were subject to immunohistochemistry and qPCR. When compared with normal glands, MYC was upregulated in benign and malignant MG neoplasms. Aberrant p53 expression was restricted to the nuclei of intraepithelial neoplastic cells in MG carcinomas. Adipophilin expression was diminished in MG neoplasms compared with the normal MG. Our findings, if confirmed in a larger cohort of cases, could suggest that MG oncogenesis in a dog may exhibit similar molecular features as their human counterparts.

Preputial gland adenoma in a wild nutria (Myocastor coypus): a case report

Tumor incidence in wild mammals is reportedly very low. Wild nutria, a large rodent, is known to carry many infectious diseases, but rarely exhibits neoplastic diseases. We necropsied a male wild nutria and found a large nodular mass in the left inguinal region, adjacent to the penis. Histopathologically, the mass was diagnosed as preputial gland adenoma. Spontaneous preputial gland adenomas are extremely rare in all animals. Moreover, reports of tumors in nutrias have been limited to adenocarcinomas of the lungs and uterus, as well as subcutaneous fibromas. Here, we describe preputial gland adenoma in a wild nutria.

The Detection and Association of Canine Papillomavirus with Benign and Malignant Skin Lesions in Dogs

Papillomavirus (PV) mainly infects the squamous epithelium and may potentially lead to benign or even malignant cutaneous lesions. However, the malignant transforming ability has been identified in several types of PVs. In humans, papillomavirus (HPV) type 16 and 18 are the most prevalent causative agents of cervical cancer. Therefore, vaccines are being developed to protect against these types. For dogs, there have been limited investigations into the association of different canine papillomavirus (CPV) genotypes with malignant lesions. Understanding the high-risk CPV genotype(s) responsible for these malignant lesions would contribute to the development of interventions for preventing CPV-induced carcinomas. In the present study, a retrospective cohort of 102 pathologically confirmed papillomas and 212 squamous cell carcinomas (SCCs) were included. The viral genome and antigens in the formalin-fixed paraffin-embedded (FFPE) tissues were detected using PCR targeting pan PV E1 and COPV L1 genes and by immunohistochemistry staining (IHC), respectively. PVs were successfully detected from 11 FFPE cutaneous tissues and four oral tissues using pan PV E1- and COPV L1-based PCR, respectively. After sequencing, CPV 1, CPV 2, and CPV 6 were detected in the benign lesions using PCR and were confirmed through IHC. While CPV 9 and CPV 15 were first detected in the SCCs of dogs, CPV 16 was most often detected in SCC specimens. The association and confirmative demonstration of viral genes and intralesional antigens of CPV 9, CPV 15, and CPV 16 in SCCs highlight the potential risk of these genotypes of CPVs in malignant transformation.