Endodermal sinus tumor of vagina in infants.

Endodermal sinus tumor (or Yolk Sac tumor) of the vagina is a rare malignant germcell tumor which is seen exclusively in children younger than 3 years of age. We report two cases of endodermal sinus tumor of the vagina. In both cases no radiological investigation was done and serum alpha-fetoprotein was elevated. The histopathological examination of both the tumor masses revealed vaginal endodermal sinus tumor. Periodic-acid-Schiff stain with diastase showed diastase resistant hyaline globules. These findings confirmed the diagnosis of endodermal sinus tumor in both cases. Vaginal endodermal sinus tumor is both locally aggressive and capable of metastasis. The serum alpha-fetoprotein level is a useful marker for diagnosis and monitoring the recurrence of vaginal endodermal sinus tumor in infants. Early detection and therapy is important because of its aggressive nature and good response to chemotherapy.