<prompt> Schiller Dual bodies are seen inEndodermal sinus tumorGranulosa cell tumorDysgerminomaDermoid  <response>: Ans. a Endodermal sinus tumor Ref. Dutta Gynecology 4thpg. 354SCHILLER-DUVAL BODIES are characteristic structures resembling fetal glomeruli composed of a central blood vessel surrounded by embryonal cells lying within a space also lined by embryonal cells. They are seen in endodermal sinus tumors yolk sac tumors. AFP is its tumor marker. 