Thymomas are tumors of the anterior mediastinum. They are most often s
een in adults aged 45 to 50 years. These tumors are routinely asymptom
atic for prolonged periods of time. The most common presentation is di
scovery on routine chest x-ray. We therefore present a case report of
an elderly woman who presented with symptoms of dyspnea caused by a ma
lignant thymoma. To our knowledge, symptomatic pericardial tamponade d
ue to a thymoma with a massive pericardial effusion has not been descr
ibed previously.