Association of endodermal sinus tumour, testicular teratoma and alpha1-fetoprotein.

An endodermal sinus tumour in the retroperitoneal region was associated with the presence of alpha1-fetoprotein (AFP) in the patient's serum. At autopsy a simple cystic teratoma of the right testicle was also found. The association of these two tumours has been reported before. The classification of these malignant germ-cell tumours and an understanding of their evolution may be aided by the discovery that AFP is often found in the patient's serum.