We would like to report a case of bovine lymphosarcoma. Parous cattle from a livestock farmhouse were examined for mutinodular masses in the abdominal cavity after slaughter. For clinical signs, animals presented mild leukemic signs but did not have viral or bacterial infection. Grossly, whitish to yellowish smooth masses similar to fat tissue were covered with a thin membrane. A multilobulated mass formed around the arteri, and there was a large quantity of reddish fluid on the cut surface. Histopathologically, a monomor- phic population of lymphocytes was observed along with small amounts of cytoplasm, round nuclei with coarsely granular chromatin, and numerous mitotic figures in the samples. In the tumor lesion, uniformly round cells had invaded with abundant neovascularization. Especially, the immunohistochemical phenotype of tumor cells was posi- tive for anti-CD3 and negative for anti-CD8 and anti-CD20. Therefore, morphological analysis diagnosed the mass as a multinodular bovine lymphosarcoma of T-cell origin with- out any sign of infection by a viral agent.

• Joon-Young Yang(Department of Pathology, College of Veterinary Medicine, Kyungpook National University, Stem Cell Therapeutic Research Institute, Kyungpook National University)
• Da-Hee Jeong(Department of Pathology, College of Veterinary Medicine, Kyungpook National University, Stem Cell Therapeutic Research Institute, Kyungpook National University)
• Chang-Woo Min(Department of Pathology, College of Veterinary Medicine, Kyungpook National University, Stem Cell Therapeutic Research Institute, Kyungpook National University)
• Kyung-Ku Kang(Department of Pathology, College of Veterinary Medicine, Kyungpook National University, Stem Cell Therapeutic Research Institute, Kyungpook National University)
• Ah-Young Kim(Department of Pathology, College of Veterinary Medicine, Kyungpook National University, Stem Cell Therapeutic Research Institute, Kyungpook National University)
• Eun-Mi Lee(Department of Pathology, College of Veterinary Medicine, Kyungpook National University, Stem Cell Therapeutic Research Institute, Kyungpook National University)
• Eun-Joo Lee(Department of Pathology, College of Veterinary Medicine, Kyungpook National University, Stem Cell Therapeutic Research Institute, Kyungpook National University)
• Myeong-Mi Lee(Department of Pathology, College of Veterinary Medicine, Kyungpook National University, Stem Cell Therapeutic Research Institute, Kyungpook National University)
• Sang-Hyeob Kim(Department of Pathology, College of Veterinary Medicine, Kyungpook National University, Stem Cell Therapeutic Research Institute, Kyungpook National University)
• Soo-Eun Sung(Department of Pathology, College of Veterinary Medicine, Kyungpook National University, Stem Cell Therapeutic Research Institute, Kyungpook National University)
• Kyu-Shik Jeong(Department of Pathology, College of Veterinary Medicine, Kyungpook National University, Stem Cell Therapeutic Research Institute, Kyungpook National University) Corresponding Author