Primary cardiac B-cell lymphoma presented as heart tamponade and atrioventricular block: a case report.

BACKGROUND: Primay cardiac lymphoma is rare, and its diagnosis is not determined until autopsy.

CASE: A 49-year-old man presented with heart tamponade and atrioventricular block. Bloody pericardiac effusion showed a monotonous proliferation of atypical large mononuclear cells, which demonstrated a lambda light-chain monoclonality by the fluorescence-activated cell-sorter method and clonal rearrangement bands by Southern blot analysis of the IgH gene. Transvenous biopsy excised from the right atrial tumor was diagnosed as diffuse large B-cell lymphoma. He underwent chemotherapy and permanent pacemaker implantation and is alive and well.

CONCLUSION: Liquid cytology of cardiac effusion was very useful for rapid diagnosis, leading to a better prognosis.