<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>A malignant, fast-growing tumor that develops from trophoblastic cells (cells that help an embryo attach to the uterus and help form the placenta). Almost all choriocarcinomas form in the uterus after fertilization of an egg by a sperm, but a small number form in a testis or an ovary. Choriocarcinomas spread through the blood to other organs, especially the lungs. They are a type of gestational trophoblastic disease.</n0:def-definition><n0:def-source>NCI-GLOSS</n0:def-source></n0:ComplexDefinition><n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>A malignant neoplasm arising from placental trophoblast cells. They generally arise in the uterus.</n0:def-definition><n0:def-source>CDISC</n0:def-source></n0:ComplexDefinition>
<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>An aggressive malignant tumor arising from trophoblastic cells. The vast majority of cases arise in the uterus and represent gestational choriocarcinomas that derive from placental trophoblastic cells. Approximately half of the cases develop from a complete hydatidiform mole. A minority of cases arise in the testis or the ovaries. There is often marked elevation of human chorionic gonadotropin (hCG) in the blood. Choriocarcinomas disseminate rapidly through the hematogenous route; the lungs are most frequently affected.</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>