<prompt> Syncitiotrophoblast is seen in:Partial moleComplete moleChoriocarcinomaPlacental site of trophoplastoma  <response>: Ans. c ChoriocarcinomaRef: Shaws 15th ed. 1424CHORIOCARCINOMA Generally, choriocarcinoma is a part of a mixed germ cell tumour. Its origin as a teratoma can be confirmed in prepubertal girls, when the possibility of its gestational origin can be definitely excluded. The tumours are very vascular. Histologically the tumor shows adimorphic population of syncytiotrophoblasts and cyto-trophoblasts. It secretes large quantities of human chorionic gonadotropin hCG hormone, which forms an ideal tumour marker in the diagnosis and management of the tumour. The tumour is highly malignant, and metastasizes by bloodstream to the lungs, brain, bones and other organs. 