[Yolk-sac tumours of the mediastinum (author's transl)].

Three patients with yolk-sac tumours of the mediastinum have been described. This is a rare primary germ layer tumour of the thorax. Most commonly it is situated anteriorly in the mediastinum. Only rarely is it found in the posterior mediastinum. Only males are affected. In most patients the prognosis, despite intensive radiation and chemotherapy, is extremely poor.