Yolk Sac Tumor which is previously known as endodermal sinus tumor, is an unusual malignant germ cell neoplasm, which mostly women and teenagers. Although YST is the third most common menacing germ cell tumor of the ovary it consists of only 1% of all ovarian menaces. Extra gonadal YST is an extremely rare menace, representing 2-5% of all adult germ-cell menaces. During embryogenesis, at the fourth over the six weeks of growth, germ cells travel through the urogenital ridge. Mislaying and a remnant tissue anywhere along the migration course may be a cause in the pathogenesis of extra gonadal YSTs.