Chorioangioma, placental: A benign tumor of a blood vessel in the placenta. Large chorioangiomas can cause complications, including excess amniotic fluid (polyhydramnios), maternal and fetal clotting problems (coagulopathies), premature delivery, toxemia, fetal heart failure, and hydrops (excess fluid) affecting the fetus. Chorioangiomas probably act as shunts between arteries and veins (arteriovenous shunts), leading to progressive heart failure of the fetus.
Choriocarcinoma: A highly malignant tumor that arises from trophoblastic cells within the uterus. Choriocarcinoma tends to be invasive and to metastasize early and widely through both the venous and lymphatic systems. Choriocarcinoma is one of the two types of gestational trophoblastic tumor, the other being hydatidiform mole. Choriocarcinoma may follow any type of pregnancy. It […]
Chorion: The outermost of the two fetal membranes (the amnion is the innermost) that surround the embryo. The chorion develops villi (vascular finger-like projections) and develops into the placenta.
- Chorionic villus sampling
A procedure for first-trimester prenatal diagnosis. Abbreviated CVS. CVS may be done between the eighth and tenth weeks of pregnancy. The aim is to diagnose severe abnormalities that are present in the fetus. Tissue is withdrawn from the villi of the chorion, a part of the placenta, and then prepared for diagnostic analysis.
Choroid: In the eye, a thin vascular layer between the sclera and the retina. The choroid supplies blood to the retina and conducts arteries and nerves to other structures in the eye.
Choroiditis: An inflammation of the layer of the eye behind the retina, either in its entirely (multifocal choroiditis) or in patches (focal choroiditis). Usually the only symptom is blurred vision. See also uveitis.