# Diffuse large B-cell lymphoma with DNA copy number changes in a Japanese black calf

## TL;DR

A 2-month-old Japanese Black calf was diagnosed with diffuse large B-cell lymphoma, and DNA copy number changes were found to potentially contribute to the disease.

## Contribution

The study reports DNA copy number variations in a calf with DLBCL, suggesting their potential role in lymphoma onset in cattle.

## Key findings

- The calf was diagnosed with centroblastic diffuse large B-cell lymphoma based on histopathological and immunohistochemical findings.
- DNA copy number analysis showed increased GIMAP family copy numbers and decreased copy numbers of GBP-1, MIR3141, OR5P1E, and PTPRG.
- These DNA copy number changes may have contributed to the onset of DLBCL in the calf.

## Abstract

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.

The online version contains supplementary material available at 10.1007/s11259-024-10371-7.