Farjanikish, G., O. Dezfoulian & K. Qeisarbeigi, 2018. T cell lymphoma in the atrium of a young bull. Bulg. J. Vet. Med., 21, No 4, 483–488.

DOI: 10.15547/bjvm.1078

In this report, T-cell lymphoma in the atrium of a 1.5-year-old Holstein bull is described. Macroscopically, a large white to a yellow tumour mass with a size of 4.5×3.5×2 cm was observed in the left atrium. Histopathological examination revealed extensive infiltration of medium- to large-sized lymphocytic cells with round to oval nuclei and stippled chromatin, surrounded by a narrow rim of pale eosinophilic cytoplasm. Immunohistochemically, the tumour cells indicated positivity with CD3 and Ki-67, but negativity with CD79α, CD20 and S100. On the basis of the histologic and immunohistochemical findings, this tumour was diagnosed as a T-cell lymphoma.

Key words: atrium, cow, immunohistochemistry, lymphoma