Atypical subtype of sporadic bovine leukosis in an adult crossbred bull: A case report

In the present study, a bull aged nine years with a history of fever and enlarged lymph nodes (LNs) was presented to the post mortem facility of Department of Veterinary Pathology, Guru Angad Dev Veterinary and Animal Sciences, University thorough necropsy examination revealed enlargement of prescapular, bronchial and mesenteric lymph nodes with loss of corticomedullary differentiation and yellow creamish surface with haemorrhages. An interesting solitary hard mass was found near the right kidney. Cytological examination of LNs and hard mass revealed anaplastic changes in lymphoid cells. Histopathological examination of affected LNs and hard mass revealed medium to large sized lymphocytes with few mitotic figures that replaced the follicles and sinuses. Moreover, these neoplastic cells of LNs and hard mass were found to be immunopositive with CD3 antibody only and immunonegative with PAX-5 and BLV p24 (capsid protein) antibodies suggesting a case of sporadic bovine leukosis. However, the intriguing aspect of present case was that, neither the thymus nor the skin was affected along with the presence of atypical hard mass, indicating that it does not fall under either of the categorization of sporadic bovine leucosis. .Hence, the present case based on age, gross, cytological, histological and immunohistochemical findings, was classified as an atypical form of Sporadic Bovine Leukosis.