The endodermal sinus tumor: special features

Eight cases of endermal sinus tumor, two extragonadal and six gonadal, seen at the American University of Beirut are reviewed. Three of them present special clinical and pathologic features that further substantiate the extraembryonic origin of this teratoid tumor and its association with dysgenetic gonads. We consider the two histologic types, endodermal sinus pattern and polyvesicular vitelline architecture, to be part of the same tumor. The prognosis in this series was unfavorable.