Molar pregnancy

A pregnancy in which a tumour develops from the placental tissue and the embryo does not develop normally. A molar pregnancy may be noncancerous (a hydatidiform mole) or may invade the wall of the uterus (an invasive mole). A molar pregnancy that becomes cancerous is called a choriocarcinoma. If the dead embryo and placenta are not expelled from the uterus after a miscarriage, the dead tissue is called a carneous mole.