A clinical case of enzootic bovine leukosis diagnosed by malignant lymphoma cells detected in urinary sediment

A Holstein cow presented with decreased milk production. Rectal palpation revealed masses in the pelvic cavity without enlargement of superficial lymph nodes. The cow maintained a continuing urination posture after urination and yellow cloudy urine drops were observed. Cytology of urine sediment revealed large atypical lymphoid cells suggestive of lymphoma. Hematology examination showed lymphocytosis with atypical lymphocytes. Increased activities of serum lactate dehydrogenase and thymidine kinase were also suggestive of lymphoma. PCR for bovine leukemia virus was positive. B-cell clonality PCR to define the rearrangement of immunoglobulin heavy chain revealed monoclonal growth of B-cells. These findings led to a diagnosis of enzootic bovine leukosis (EBL). Examination of urinary sediment can be diagnostic for EBL with lesions in the urinary system.