Etiology and Pathogenic Mechanisms Involved in the Urothelial Tumors in Cattle

Abstract

Urinary bladder and urethral tumors have a low incidence, except in cattle, where enzootic hematuria is associated with both epithelial and/or non-epithelial tumors and preneoplastic lesions. Urinary tract tumors are often invasive and have a high metastasizing capacity.The aims of the present study was to evaluate the etiology of urothelial lesions in cattle, to morphologically asses both preneoplastic and tumoral lesions and to make a correlation between the infection with Bovine Papillomavirus, type 1, 2 and 4 and the consumption of bracken fern in cattle from geographical areas where chronic haematuria has an enzootic character. 50 biopsies were taken into study from a total number of 400 cattle taken to the slaughterhouse between October 2011 and March 2013; they were analyzed using histopathology (hematoxylin-eosin stain), immunohistochemistry and molecular analysis for the BPV infection serotypes 1, 2 and 4. The immunohistochemistry markers we used were panCK (for epithelial tissues) and Ki-67 (a proliferation marker). After the gross pathological and histopathology examination of the bladders, we found that 60% of the lesions were of preneoplastic nature (including circulatory and inflammatory lesions) and 40% tumoral lesions were identified (in situ carcinomas, proliferative urothelial neoplasms with a low malignancy potential, adenocarcinomas and squamous cell carcinomas). The expressions of panCK and Ki-67 markers were intense and uniform in both preneoplastic and tumoral lesions. Through polymerase chain reaction technique, DNA from Bovine Papillomavirus was identified in a high percentage in tumoral lesions and a much lower percentage in non-tumoral lesions. We concluded that serotype 2 infection has an important role in urinary bladder carcinogenesis in cows from Romania, in areas where bracken fern causes enzootic hematuria.