[Gonadal and extragonadal yolk sac tumor].

Yolk-sac tumours are germ-cell tumours with gonadal and extragonadal location. Histologically they consist of primitive cellular forms configurated as a loose network. These tumours are of extreme malignancy and should be treated as radical as possible. Surgery should be combined with anticancer chemotherapy. However, with adequate treatment only children suffering from testicular tumours and not older than 2 years of life have a fair chance to survive. 3 cases are dealt with in detail.