Ultrasound features of placental chorioangioma detected by SMI technology before and after thrombosis of feeding vessels: analysis of a clinical case

Objective: Placental chorioangioma is the most common non-trophoblastic vascular benign tumor of the placenta, with an estimated incidence of 1% of all pregnancies. Most chorioangiomas are small asymptomatic lesions that are found incidentally only postnatally during histologic examination of the placenta. Voluminous chorioangiomas (>4–5 cm), however, are less common and are more often diagnosed prenatally, through ultrasound imaging. Color Doppler demonstrates either a single blood vessel feeding the lesion or substantial vascularity within the mass. Large tumors have been associated with multiple adverse perinatal outcomes, including fetal growth restriction, preterm birth, polyhydramnios, fetal congestive heart failure, fetal anemia, fetal hydrops and intrauterine death. Case(s): A 35-years-old primigravida woman with uncomplicated pregnancy was referred to the Ultrasound Centre of Obstetric and Gynecologic of Sant’Anna Hospital, Turin, due to a suspect placental mass seen during the ultrasound performed at 32 weeks of gestation. In this case, detailed ultrasound scans with grey scale and Doppler examination were performed (using Aplio 550; Canon Medical Systems Europe BV, Zoetermeer, The Netherlands). We also decided to study the vascularization of the mass with SMI (superb microvascular imaging) technology. In particular, with the use of SMI, it was possible to visualize the vascularization of the mass more completely which was conspicuous at first but disappeared after thrombosis of feeding vessels with favorable pregnancy outcome. Conclusion: SMI is a new vascularity imaging method that can visualize vessels that exhibit slow flow rates. It uses a system to reduce artifacts by greatly reducing interference from tissue movement.