CASE Images
An 84-year-old male with an unknown fever and vomiting presented to our institution. His electrocardiogram demonstrated sinus pauses up to 10 seconds. We thought the sinus arrest was caused by hyperkalemia (potassium of 6.9 mEq/L) followed by worsening renal function (blood urea nitrogen 84.6 mg/dL and creatinine 4.77 mg/dL). We immediately placed a temporary pacemaker and performed continuous hemodiafiltration, however, regardless of multidisciplinary treatment, he died on the thirty-eighth day of admission. His autopsy revealed cardiac involvement of diffuse large B-cell lymphoma (DLBCL). The diffuse infiltrated large lymphoid cells were observed to have right atrial dominance (Figure A). In this clinical course, the electrocardiogram demonstrated atrial tachycardia with 3:1 conduction and atrial fibrillation (Figure B). Both tachycardias were followed by sinus arrest. The patient presented with various types of arrhythmias such as sick sinus syndrome, atrial tachycardia, and atrial fibrillation. Theoretically, the infiltrated DLBCL invaded the sinus node and right atrium, then induced these various arrhythmias in this case. Alternatively, cardiac involvement of malignant lymphoma is usually non-symptomatic1. It is important not to dismiss a rare symptomatic case of cardiac involvement of malignant lymphoma since there were various types of arrhythmias that might have been treated with chemotherapy2.