Multicentric T cell lymphosarcoma in a Jeju native boar

A 7-year-old Jeju native boar was requested to the Veterinary Pathology Laboratory of Cheju National University with a clinical signs of anorexia, melena, lethargy and sudden death. At necropsy, four coalescing firm masses were occupied in the abdominal cavity between ventral surface of stomach and pancreas. Individual mass was a yellowish white in color and up to 6 cm in diameter. These masses were not encapsulated and bulged from the cut surface. Liver and spleen were enlarged and pale nodules were presented in these tissues. Some yellowish white nodules up to 5 mm in diameter were scattered in kidneys. Histopathologically, lymphoblastic tumor cells were occupied in the abdominal masses, multifocal areas of liver, kidneys, and spleen. Morphologically lymphoblastic tumor cells were round to oval in shape, and medium to large in size. They had round to oval nuclei, moderate amount of eosinophilic cytoplasm, and many mitotic figures. Immunohistochemistry revealed that tumor cells were CD3-positive and $CD79{\alpha}$-negative, consistent with T-cell lineage. Based on gross, microscopic findings and immunohistochemistry, this case was diagnosed as porcine multi-centric T cell lymphosarcoma. In animals, as in human, the T-cell lymphomas are generally more aggressive than B cell types and respond less well to therapy. In our best knowledge, this is the first report for porcine T cell lymphosarcoma in Korea.