[4] Diagnosis of EST in pregnant women and in infants is complicated by the extremely high levels of AFP in those two groups.

[medical citation needed] EST can have a multitude of morphologic patterns including: reticular, endodermal sinus-like, microcystic, papillary, solid, glandular, alveolar, polyvesicular vitelline, enteric and hepatoid.

[medical citation needed] Schiller–Duval bodies on histology are pathognomonic and seen in the context of the endodermal sinus-like pattern.

[8] Before modern chemotherapy, this type of neoplasm was highly lethal, but the prognosis has significantly improved since then.

[citation needed] When endodermal sinus tumors are treated promptly with surgery and chemotherapy, fatal outcomes are exceedingly rare.