Mediastinal yolk sac tumour mimicking pericardial effusion.

In this report we present a case ofprimary yolk sac tumour of the anterior mediastinum in which two dimensional echocardiography showed an extracardiac mass simulating a large pericardial effusion. Mediastinal yolk sac tumour is a rare germ cell neoplasm affecting mainly young men.' The most common presenting symptoms are dyspnoea, cough, and chest pain.2 The prognosis is usually poor, though in this case complete resolution of the tumour has been achieved.