Malignant lymphoma demonstrating sick sinus syndrome.

We report a case of T-cell-rich large B-cell lymphoma demonstrating sick sinus syndrome as a single initial symptom, followed by the retention of pericardial and pleural effusions. Intrapleural administration of interferon-alpha prevented reaccumulation of the pleural effusion for one and a half months, whereas systemic chemotherapy failed to control tumor growth in the skin and lymph nodes. The autopsy revealed involvement of the sinoatrial node of the heart by lymphoma cells.