Intermediate between the hydatidiform mole and a choriocarcinoma is an invasive mole. Despite invasion into, or even through, the uterine wall or to the vagina, there are still villi, and the mole is not malignant. However, invasive moles can cause hemorrhage and portions can embolize to the lungs. Curretment alone may not achieve removal, so chemotherapy may be needed to produce resolution.