_:vb50953840 . _:vb50953840 . _:vb50953840 . _:vb50953840 . _:vb50953840 . _:vb50953840 "url:https://en.wikipedia.org/wiki/Endodermal_sinus_tumor"^^ . _:vb50953840 "An ovarian primitive germ cell tumor that has_material_basis_in cells that line the yolk sac of the embryo."^^ .