Polyhydramnios secondary to placental chorioangioma

Chorioangioma is the most common tumor of the placenta, occurring in approximately 1% of pregnancies. This entity is a benign vascular tumor composed of fetal vascular elements joined by connective tissue and is usually found in contact with the chorionic plate or surrounding areas. Size is highly variable but chorioangiomas usually have a diameter of less than 4 cm. Larger chorangiomas (5 cm or more) can occur in areas of infarction or thrombosis and are more frequently associated with complications such as polyhydramnios, preterm labor, and fetal congestive heart failure. Diagnosis of chorioangioma is made in the second or third trimester by ultrasound, which shows nodular images in the fetal side of the placenta or the inner placenta. Doppler studies reveal the presence of vascularization inside or on the periphery of the mass, although this finding is not always present. The management of this tumor ranges from close surveillance of the pregnancy to more invasive procedures such as chemosclerosis with absolute alcohol or laser devascularization. We report a case of large chorioangioma with polyhydramnios, diagnosed at 33 weeks of gestation.