<prompt> Which of the following is an impoant tumour marker in the diagnosis of endodermal sinus tumour: March 2011HCGCa-125LDHAlpha FetoProtein  <response>: Ans. D: Alpha Feto Protein Endodermal sinus yolk sac tumour is thought to originate from a multiple potential embryonal tissue as a result of selective differentiation of yolk sac structures. This explains why the tumour is rich in alpha-fetoprotein and alphal antitrypsin 