Pathology and Diagnosis of Squamous Cell Carcinoma in Bovines

Background: A total of 20 tissue samples from horn, eye, skin and vulva in bovines suspected of squamous cell carcinoma (SCC) on the basis of gross pathology were collected from Durg, Dhamtari and Rajnandgaon districts of Chhattisgarh and processed in the Department of Veterinary Pathology, College of Veterinary Science and A.H., DSVCKV, Anjora, Durg (C.G.). Methods: Investigation was conducted during January to June 2022, we explicate the pathological and immunohistochemical examination including scoring and grading of squamous cell carcinoma in bovines. Histopathological examination as per standard HandE method of staining and immunohistochemistry was performed through Benchmark automated staining system. Result: Twelve cases were diagnosed as SCC on the basis of histopathological and eleven on the basis of immunohistochemical analysis. Grossly neoplasms of horn revealed large, cauliflower like unilateral irregular masses at the base of horn and they were friable and soft in consistency. Small, unilateral growths observed in eye varied from soft to hard in consistency. Histopathological findings in SCC of horn revealed keratinization of horn epithelium forming concentric keratin pearls. Distinctive keratin pearls with more keratin deposition towards the center, numerous mitotic figures with anaplasia and neovascularization were evident in OSCC. Immunohistochemistry revealed strong immunohistochemical expression of Pan-Cytokeratin (Pan-CK), p53 and EGFR and negative to p16. Immunohistochemical scoring (IHS) was done in Pan-CK, EGFR and p53, ranged from 1-4. Well differentiated SCC of horn revealed strong immunoexpression against EGFR, varied from mild to intense. SCC of horn exhibited strong immunoexpression for Pan-CK, p53 and EGFR whereas, immunoexpression in OSCC specifically p53 was less as compared to SCC of horn. Grading and differentiation of SCC (horn and eye) was also done on basis of histopathological and immunohistochemical scoring.