A 2-month-old Japanese Black calf exhibited mandibular and superficial cervical lymph node swelling. Fine needle aspiration cytology of the superficial cervical lymph node revealed large lymphoblast-like cells with mitoses. Hematological examination revealed remarkable lymphocytosis with atypical lymphocytes. Increased activities of serum total lactate dehydrogenase and thymidine kinase were detected. At necropsy, generalized swelling of lymph nodes was observed. Histopathological analysis revealed diffuse proliferation of medium-sized round centroblastic neoplastic cells that were positive for CD20, CD79α, PAX5, and BLA-36, and negative for CD3, CD5, CD10, and CD34. The calf was diagnosed with centroblastic diffuse large B-cell lymphoma (DLBCL) based on these findings. Analysis of DNA copy number variation revealed an increased copy number for the GIMAP family relative to that in healthy cattle. Moreover, decreases in copy numbers of GBP-1, MIR3141, OR5P1E, and PTPRG relative to those in healthy cattle were also observed. Because DNA copy number variation represent a major contribution to the somatic mutation landscapes in human tumors, these findings suggest that DNA copy number changes might have contributed to the onset of DLBCL in the present case.

一头2个月大的日本黑牛出现下颌和颈浅淋巴结肿胀。颈浅淋巴结的细针抽吸细胞学检查显示有有丝分裂的大淋巴母细胞样细胞。血液学检查发现淋巴细胞明显增多，伴有非典型淋巴细胞。检测到血清总乳酸脱氢酶和胸苷激酶活性增加。尸检时，观察到淋巴结普遍肿胀。组织病理学分析显示中等大小的圆形中央母细胞肿瘤细胞弥漫性增殖，这些细胞对 CD20、CD79α、PAX5 和 BLA-36 呈阳性，对 CD3、CD5、CD10 和 CD34 呈阴性。根据这些发现，该小牛被诊断患有中心母细胞弥漫性大 B 细胞淋巴瘤 (DLBCL)。 DNA 拷贝数变异分析显示，与健康牛相比，GIMAP家族的拷贝数有所增加。此外，还观察到与健康牛相比，GBP-1、MIR3141、OR5P1E和PTPRG的拷贝数减少。由于 DNA 拷贝数变异是人类肿瘤体细胞突变景观的主要贡献者，这些发现表明 DNA 拷贝数变化可能导致了本病例中 DLBCL 的发生。