Solid masses on the fetal surface of the placenta: differential diagnosis and clinical outcome.

We identified 10 cases of solid masses on the fetal surface of the placenta prospectively that were thought to represent chorioangiomas. Pathologic assessment of the placenta revealed five chorioangiomas and five placental hemorrhages. The five chorioangiomas ranged in size from 4 to 10 cm and four of these five fetuses were delivered uneventfully at term. Only one fetus showed evidence of cardiac decompensation and did not survive. Three of the five women with placental bleeds delivered their infants between 33 and 34 weeks' gestation, but all five infants did well. This series shows that the sonographic appearance of chorioangioma was indistinguishable from placental hemorrhage, and even large chorioangiomas may be associated with good neonatal outcome.