Endodermal sinus tumor of the nasopharynx and previous mature congenital teratoma.

Congenital teratoma of the nasopharynx is a rare tumor that has shown consistently benign behavior. In contrast, endodermal sinus tumor, even more unusual nasopharyngeal germ cell tumor, displays consistently aggressive behavior with most reports documenting early death of the patient. We report the clinicopathological features of a case of endodermal sinus tumor of the nasopharynx that developed in a 3-year-old girl who had a mature teratoma excised from the same site in the neonatal period. Local recurrence of the endodermal sinus tumor was followed by disseminated disease and death within 18 months.