Paraffin sections of superficial and iliac lymph nodes of forty eight cows seropositive and two seronegative to Bovine Leukemia Virus (BLV) were examined in order to detect possible histological changes related to bovine lymphossarcoma. Thirty animals seropositive and one seronegative showed cytologic pictures of lymphoid hyperplasia (LH), ten showed benign lymphadenopathy and seven animals presented with LH and reticular hyperplasia (RH) simultaneously. All those changes are of benign nature and apparently they do not relate to the infection with BLV. None of the sections evidenced conclusively the existence of neoplastic lesions. However, sections of lymph nodes from eight animals seropositive to BLV showed histological changes suggestive of the initial phases of neoplastic transformation. Nonetheless based upon those changes only and due to the impossibility of a clinical and histological follow up of the animals, it was not possible to draw any definitive conclusion over the nature of those changes.
bovine leukemia virus; lymphossarcoma; histological lesions.
