NCI Dictionary of Cancer Terms
The NCI Dictionary of Cancer Terms features 8,468 terms related to cancer and medicine.
We offer a widget that you can add to your website to let users look up cancer-related terms. Get NCI’s Dictionary of Cancer Terms Widget.
- molar pregnancy
- listen (MOH-ler PREG-nun-see)
- A slow-growing tumor that develops from trophoblastic cells (cells that help an embryo attach to the uterus and help form the placenta) after fertilization of an egg by a sperm. A molar pregnancy contains many cysts (sacs of fluid). It is usually benign (not cancer) but it may spread to nearby tissues (invasive mole). It may also become a malignant tumor called choriocarcinoma. Molar pregnancy is the most common type of gestational trophoblastic tumor. Also called hydatidiform mole.