Clinical and immunohistochemical evaluation of penile tumors in bulls

Fibropapilloma is the most common neoplasic formation associated with bovine papillomavirus type I. It occurs inside the penis of bulls and causes clinically adverse effects, such as phimosis, paraphimosis, urethral stricture, and urinary retention. This study aimed to conduct a clinical and immunohistochemical evaluation of penile tumors, which are associated with adverse outcomes with regard to breeding value and yield in bulls.A total of 40 bulls of different breeds aged between 10 months to 3 years were included in the study. Tumor tissue samples collected postoperatively were fixed in 10% buffered formaldehyde solution. The avidin–biotin–peroxidase method was used for immunohistochemical staining. Three separate areas were examined under 40X objective lens for each fibropapilloma tissue. The immunoreactivity was classified as none (-), mild (+), moderate (++), and severe (+++). Fibropapillomas ranged from 2 to 10 cm in diameter. Thirty-two papillomas were pedunculated and eight were sessile and attached to the body; 30 were solitary and 10 were multiple. There were 13 relapsed cases and 27 non-relapsed cases. Immunohistochemical examination revealed a statistically significant difference in the binary comparisons of proliferating cell nuclear antigen (PCNA) and hypoxanthine-guanine phosphoribosyltransferase (HPRT) based on positive cell scoring between the relapsed and non-relapsed cases. As a result, it was concluded that the clinical data together with the cancer markers, which were used in the immunohistochemical evaluation and were of great importance in terms of the prognosis of penile tumors that caused significant economic losses, are useful parameters in evaluating the malignancy of penile tumors.