Prenatal diagnosis of a placental cyst: comparison of postnatal biochemical analyses of cyst fluid, amniotic fluid, cord serum, and maternal serum

Structured evaluation and reporting in imaging of placenta and umbilical cord

The human placenta plays a pivotal role in development and growth of the fetus. Disorder of this multifunctional organ is central to various fetal disorders. Doppler sonography and MRI provide excellent diagnostic evaluation of the placental morphology and umbilical cord. Decades of experience in obstetric imaging have highlighted the need of careful prenatal assessment of placenta. However, in most of the routine obstetric scans, the evaluation and reporting of the placental examination is limited to the location and grade of the placenta. The purpose of this article is to review the existing literature and facilitate step-by-step evaluation of the placenta and umbilical cord by the radiologists.

Placental Chorionic Cyst Fluid Has Prothrombotic Properties and Differs From Amniotic Fluid

INTRODUCTION

Chorionic cysts of the chorion laeve, fetal chorionic plate, septum, and free membranes have been associated with placental hypoxia, but they have no clear clinical significance. Although immunohistochemistry has identified fibronectin and collagen IV in cyst fluid, the contents have yet to be fully characterized.

METHODS

Placental chorionic cysts (N = 10) were sampled by fluid extraction and hemotoxylin and eosin-stained sections. Amniotic fluid samples (N = 8) were obtained from pregnant women who had cytogenetic evaluation. The content of the cysts was tested for thrombogenicity using thromboelastography. The cyst content was tested by Luminex multiplex and ELISA assays and for known prothrombotic and proinflammatory factors.

RESULTS

We identified cysts, especially those in the chorionic plate, adjacent to intervillous thrombi with apparent cyst rupture. Thromboelastography revealed a significantly shorter R time compared to whole blood control samples. Concentration of creatinine, α-fetoprotein, and surfactant D in the cyst fluid differed significantly from amniotic fluid. Cyst fluids had a significantly higher expression of all prothrombotic and some proinflammatory factors.

DISCUSSION

Our data provide the first evidence that chorionic cyst fluid is prothrombotic and different from amniotic fluid. The association of ruptured cysts with adjacent thrombi and the prothrombotic properties of cyst fluid suggest a causal relationship; however, further studies are needed.

Three-dimensional sonography of placental mesenchymal dysplasia and its differential diagnosis

OBJECTIVE

Placental mesenchymal dysplasia (PMD) is an uncommon vascular anomaly of the placenta characterized by mesenchymal stem villous hyperplasia. Its main sonographic feature is a thickened placenta with hypoechoic areas, and an accurate sonographic diagnosis is challenging. The aim of this study was to report 2 cases of PMD and discuss the differential diagnosis of its sonographic features.

METHODS

Cases of placental masses were studied by 2-dimensional (2D), 3-dimensional (3D), and color Doppler imaging.

RESULTS

In case 1, a thick placenta with multiple hypoechoic areas was noted at 13 weeks' gestation. At 19 weeks, the multicystic area, clearly demarcated from a normal-looking placenta, measured 6.5 x 8.5 cm and enlarged gradually. The patient gave birth to a 625-g female neonate after spontaneous labor at almost 26 weeks' gestation. In case 2, a first sonographic examination at 25 weeks' gestation revealed a thickened placenta with hypoechoic areas and a fetus with a single umbilical artery and a ventricular septal defect. At 27 weeks, the abnormal area of the placenta measured 14.5 x 7.5 cm. At 32 weeks' gestation, a caesarean delivery was performed because of a nonreassuring fetal heart tracing, and a 1415-g female neonate was delivered. Both cases were evaluated by 2D, 3D, and color Doppler imaging, and the pathologic features of both placentas were consistent with PMD.

CONCLUSIONS

Placental mesenchymal dysplasia should be considered in the differential diagnosis of every placental mass, especially in cases of multicystic placental lesion with lack of high-velocity signals inside the lesion, and a normal karyotype.