# A case report: Null-cell cardiac lymphoma in an English bulldog

## TL;DR

A middle-aged English bulldog was diagnosed with a rare high-grade null-cell lymphoma in the heart, leading to euthanasia and post-mortem confirmation.

## Contribution

This report presents a novel case of null-cell cardiac lymphoma in a dog, expanding the understanding of lymphoma subtypes in veterinary medicine.

## Key findings

- The dog had thickened heart walls and nodules consistent with high-grade lymphoma.
- Neoplastic cells lacked immunoreactivity to T-cell, B-cell, plasma cell, mast cell, and histiocyte markers.
- The aortic root mass was confirmed as a chemodectoma, unrelated to the lymphoma.

## Abstract

This case report describes a novel example of an extranodal null-type lymphoma in the myocardium of a middle-aged English bulldog who presented with signs of right heart failure. An echocardiogram found, in addition to the pericardial effusion, thickened right and left ventricular free walls and the interventricular septum. The right ventricular free wall myocardium had multinodular lesions, suspicious for infiltrative disease. The owner elected humane euthanasia, and permission for necropsy was obtained. Multifocal left and right ventricular nodules and an incidental aortic root mass were detected, the latter of which was later confirmed as a chemodectoma. Microscopically, the myocardial nodules were sheets of round cells consistent with a high-grade lymphoma. Neoplastic cells were not immunoreactive to CD3 (T-cell) or CD20 and CD79a (B-cell), Mum-1 (plasma cell), CD117 (mast cell), or CD18 (histiocyte). These findings are consistent with a high-grade, null-cell-type lymphoma.