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

Thick Placenta in Pregnancy: A Review

Importance

A thickened placenta is easily identified on ultrasound and provides insight into maternal and fetal wellbeing as well as underlying structural and physiologic anomalies.

Objectives

The aim of this study was to review the literature to clarify what classifies a placenta as "thickened" and to review the associated incidence, maternal and fetal comorbidities, and management during pregnancy.

Evidence Acquisition

Electronic databases (PubMed and Web of Science) were searched from 2000 to 2020 in the English language. Studies were selected that examined associations between placental thickness, potential etiologies, and obstetric outcomes.

Results

There were 140 abstracts identified. After reviewing the articles, 60 were used in this review. Routine assessment of the placenta in the prenatal period is an easy and inexpensive way to assess the maternal and fetal patients. The criteria for a "thickened placenta" vary between studies based on gestational age, placental location, measurement technique, and maternal or fetal factors. Whereas most suggest thickness exceeding 4 cm is pathologic, a review had a threshold of 6 cm in the third trimester to classify placentomegaly. Several maternal and fetal conditions have been associated with a thickened placenta, such as obesity, parity, anemia, diabetes, preeclampsia, cardiac dysfunction, infection, assisted reproductive technology, multiple pregnancy, sacrococcygeal teratomas, and Beckwith-Wiedemann syndrome. A thickened placenta in pregnancy is associated with a higher incidence of adverse pregnancy outcomes and neonatal morbidity and mortality.

Conclusions

The literature is clear that early evaluation of the placenta using ultrasound should be a standard practice. A thickened placenta found on routine imaging should prompt a more thorough investigation to determine the etiology of the placentomegaly. At the time of this literature review, there are no recommendations regarding modality or frequency of antenatal surveillance in pregnancies complicated by a thickened placenta. However, serial ultrasounds and weekly antenatal testing in the third trimester should be considered.

Relevance

A thickened placenta has been associated with a variety of maternal and fetal conditions and increases the risk of adverse pregnancy outcomes and neonatal morbidity and mortality.

Doppler evaluation of normal and abnormal placenta

Doppler techniques are needed for the evaluation of the intraplacental circulation and can be of great value in the diagnosis of placental anomalies. Highly sensitive Doppler techniques can differentiate between the maternal (spiral arteries) and fetal (intraplacental branches of the umbilical artery) components of the placental circulation and assist in the evaluation of the placental functional units. A reduced number of placental functional units can be associated with obstetric complications, such as fetal growth restriction. Doppler techniques can also provide information on decidual vessels and blood movement. Abnormal decidual circulation increases the risk of placenta accreta. Doppler evaluation of the placenta greatly contributes to the diagnosis and clinical management of placenta accreta, vasa previa, placental infarcts, placental infarction hematoma, maternal floor infarction, massive perivillous fibrin deposition and placental tumors. However, it has a limited role in the diagnosis and clinical management of placental abruption, placental hematomas, placental mesenchymal dysplasia and mapping of placental anastomoses in monochorionic twin pregnancies. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Placental mesenchymal dysplasia: What every radiologist needs to know

Placental mesenchymal dysplasia (PMD) is an uncommon vascular anomaly of the placenta characterized by placentomegaly with multicystic placental lesion on ultrasonography and mesenchymal stem villous hyperplasia on histopathology. Placental mesenchymal dysplasia should be considered in the differential diagnosis of cases of multicystic placental lesion such as molar pregnancy, chorioangioma, subchorionic hematoma, and spontaneous abortion with hydropic placental changes. However, lack of high-velocity signals inside the lesion and a normal karyotype favor a diagnosis of PMD. PMD must be differentiated from gestational trophoblastic disease because management and outcomes differ. We report the case of an 18-year-old female at 15 weeks of gestation with sonographic findings suggestive of placental mesenchymal dysplasia. The diagnosis was confirmed on histopathology.

Vesicules or placental lakes in ultrasonography, determining the correct etiology

The prenatal examination of the placenta is often an afterthought to that of the fetus in ultrasonography. Not giving the placenta its due may however result in potentially serious placental pathologies remaining undiscovered, notably in the presence of anechoic zones. These latter have earned numerous names, including "placental lakes", "placental venous lakes", "placental lacunae" or "placental caverns" among others, but they have received little attention in the literature. We thus feel that it is essential to review the various pathologies that placental lakes may signal, since any one of them may greatly affect patient management. The difficulty resides in the diversity of these pathologies, sometimes oncological, other times fetal, and in the potential need for multidisciplinary surgery. Some of these causes of placental lakes may result in maternal or fetal complications and/or necessitate increased and casespecific surveillance. The diagnosis and treatment of such cases requires close collaboration between sonographers, obstetricians, geneticists and pathologists. The work we present here focuses on the different etiologies to consider in the presence of a lacunar placenta and the necessary diagnostic measures. Our objective is to propose a diagnostic flowchart to aid clinicians in this dense differential diagnosis.

Diagnosis and Management of Placental Mesenchymal Disease. A Review of the Literature

Objective

To review what is currently known about placental mesenchymal dysplasia (PMD) including imaging techniques for diagnosis and differentiation from a molar pregnancy, genetics, maternal/fetal effects, and management.

Evidence Acquisition

A literature search by research librarians at 2 universities was undertaken using the search engines PubMed and Web of Science. The search terms used were "etiology" OR "cause" OR "risk" OR "risks" OR "epidemiology" OR "diagnosis" OR "therapy" OR "prognosis" OR "management" AND "placental mesenchymal dysplasia" OR "placenta" AND "mesenchymal dysplasia." No limit was put on the number of years searched.

Results

The etiology of PMD remains uncertain, although there are a number of theories on causation. An elevated maternal serum α-fetoprotein level, slightly elevated human chorionic gonadotropin level, normal karyotype, multicystic lesions on ultrasound, and varying degrees of flow within cysts using color Doppler (stained-glass appearance) are helpful in making the diagnosis. On pathologic examination of the placenta, PMD is differentiated from molar pregnancy by the absence of trophoblastic hyperplasia. Fetal complications of PMD include hematologic disorders, Beckwith-Wiedemann syndrome, liver tumors, fetal growth restriction, preterm delivery, and intrauterine fetal demise. Maternal complications include gestational hypertension, preeclampsia, HELLP (hemolysis, elevated liver function tests, low platelets) syndrome, and eclampsia.

Conclusions

Accurate diagnosis of PMD is imperative for appropriate management and surveillance to minimize adverse maternal and fetal outcomes.

Relevance

The importance of a correct diagnosis of PMD is important because it can be misdiagnosed as a partial molar pregnancy or a complete mole with coexisting normal fetus, and this can result in inappropriate management.

Multimodality imaging of placental masses: a pictorial review

Placental masses are uncommonly identified at the time of obstetric ultrasound evaluation. Understanding the pathologies presenting as placental masses is key for providing a differential diagnosis and guiding subsequent management, which may include additional imaging with magnetic resonance (MR) imaging. Potential benign entities include chorioangiomas and teratomas. Larger chorioangiomas can cause fetal cardiovascular issues from volume overload. Placental mesenchymal dysplasia has an association with fetal anomalies and detailed fetal evaluation should be performed when it is suspected. Identifying other cystic masses such as partial and complete moles is crucial to prevent erroneous pregnancy termination. This review addresses normal imaging appearance of the placenta on ultrasound and MR imaging and describes various trophoblastic and nontrophoblastic placental masses. Potential placental mass mimics including uterine contractions and thrombo-hematomas are also presented.

Prenatal imaging and pathology of placental mesenchymal dysplasia: a report of three cases

Objective: Placental mesenchymal dysplasia (PMD) is a rare vascular anomaly characterized by mesenchymal stem villous hyperplasia. Accurate differential diagnosis of PMD is crucial to predict fetal outcomes associated with serious obstetrical complications.

Methods: We reviewed the clinical and pathological features and immunohistochemical and imaging findings of three patients with PMD.

Results: First trimester sonographic cystic findings identified molar pregnancy or PMD. However, PMD was highly suspected according to the maternal serum human chorionic gonadotropin (hCG) titers, fetal karyotypes, and imaging findings. The outcome of patient 1, in whom placental multicystic areas decreased as pregnancy progressed, was a live birth. In contrast, the babies of patients 2 and 3 were stillborn, and multicystic formations detected during the first trimester completely and consistently occupied the placentas. Pathological and immunohistochemical analyses using anti-CD34 and anti-D2-40 antibodies distinguished the cisternae from multiple small vessels in the villi. Immunohistochemical analyses using anti-CK7 and anti-Ki-67 antibodies did not detect excessive proliferation of trophoblasts. Most abnormal villi associated with PMD comprised stromal cells that did not react with an anti-p57kip2 antibody.

Conclusion: In patients with PMD, if the percentage of the normal placental area decreases as pregnancy progresses, the possibility of fetal growth restriction and intrauterine fetal demise should always be considered. The immunostaining pattern of CD34 and D2-40 may represent a unique feature of PMD and can provide supporting evidence for the differential diagnosis of PMD.

Placental Mesenchymal Dysplasia (PMD) in Association With Beckwith-Wiedemann Syndrome Identified by First Trimester Sonography

Placental mesenchymal dysplasia (PMD) has commonly been identified on second trimester ultrasound in association with Beckwith-Wiedemann syndrome (BWS). In this report, a case of PMD later confirmed as Beckwith-Wiedemann is presented, which was identified by sonography in the first trimester. When faced with a first trimester finding of an enlarged cystic placenta, it is suggested that BWS be considered as a possible diagnosis and accordingly, genetic testing with methylation studies offered to the parents.

Placental mesenchymal dysplasia

Placental mesenchymal dysplasia is a rare placental lesion characterized by stem villous cystic dilation and vesicle formation, placentomegaly, and vascular abnormalities. It can be associated with growth restriction, stillbirth, Beckwith-Wiedemann syndrome, and some chromosomal abnormalities, and needs to be distinguished from its main differential diagnosis, hydatidiform mole.

Placental mesenchymal dysplasia: a case of a normal-appearing fetus with intrauterine growth restriction

In this paper, we described a placenta with vesicular lesions in a 23-year-old woman (1-gravid) who visited our hospital at 13 weeks of gestation on prenatal routine examination. Ultrasound findings showed multiple vesicular lesions which gradually increased as the pregnancy advanced, and a live normal-appearing fetus which was confirmed of IUGR at 30 weeks of gestation in her uterus. Throughout gestation, the maternal serum β-human chorionic gonadotropin level keeps normal, but the serum alpha-fetoprotein was higher than average. The patient delivered an 1800-g female without obvious anomalies at 35 weeks 5 days of gestation due to premature rupture of membrane. The diagnosis of placental mesenchymal dysplasia was determined on the pathological examination and androgenetic/biparental mosaicism in the placenta was identified by immunohistochemical staining of p57kip2.

A case of placental mesenchymal dysplasia

Placental mesenchymal dysplasia (PMD) rarely complicates with pregnancy. A 30-year-old woman, gravida 3, para 3, presenting with placentomegaly, was referred to our department at 18 weeks of gestation. An ultrasonography revealed a normal fetus with a large multicystic placenta, measuring 125 × 42 × 80 mm. The border between the lesion and normal region was not clear. Color doppler revealed little blood flow in the lesion. Magnetic resonance imaging revealed normal fetus and a large multicystic placenta. Serum human chorionic gonadotropin level was 20124.97 U/L, which was normal at 20 weeks of gestation. Thus, placental mesenchymal dysplasia rather than hydatidiform mole with coexistent fetus was suspected. Then, routine checkup was continued. Because she had the history of Cesarean section, an elective Cesarean section was performed at 37 weeks of gestation, and 2520 g female infant with apgar score 8/9 was delivered. The baby was normal with no evidence of Beckwith-Wiedemann syndrome. Placenta of 20 × 16 × 2 cm, weighing 720 g, was bulky with grape like vesicles involving whole placenta. Microscopic examination revealed dilated villi and vessels with thick wall which was lacking trophoblast proliferation. Large hydropic stem villi with myxomatous struma and cistern formation were seen. PMD was histopathologically confirmed.

Systematic review of sonographic findings of placental mesenchymal dysplasia and subsequent pregnancy outcome

OBJECTIVE

To describe the sonographic features and pregnancy outcomes of placental mesenchymal dysplasia (PMD), an entity often misdiagnosed as molar pregnancy.

METHODS

We reviewed PMD cases from our institution and performed a systematic review of the existing literature. Inclusion criteria for the review were diagnosis of PMD as defined by placental pathology, description of placental morphology on antenatal ultrasound and reporting of pregnancy outcomes.

RESULTS

We found three cases of PMD at our institution. Patient 1 had elevated human chorionic gonadotropin (hCG) and an enlarged, hydropic placenta at 13 weeks, suggestive of a molar pregnancy. Patient 2 also had elevated hCG with large, vascular placental lakes on ultrasound suggesting placenta accreta or molar pregnancy. Case 3 involved placentomegaly and fetal anomalies suggestive of Beckwith-Wiedemann syndrome. From the literature review, 61 cases met the inclusion criteria. The most common sonographic features included enlarged (50%) and cystic (80%) placenta with dilated chorionic vessels. Biochemical aneuploidy screening abnormalities were relatively common as were fetal anomalies, Beckwith-Wiedemann syndrome and other genetic abnormalities. Pregnancy complications included intrauterine growth restriction (IUGR; 33%), intrauterine fetal death (IUFD; 13%), and preterm labor (33%). Pregnancies without fetal anomalies, IUGR, IUFD or preterm labor had normal neonatal outcomes despite PMD (9%).

CONCLUSIONS

The differential diagnosis of PMD includes molar pregnancy and other placental vascular anomalies. PMD is associated with adverse pregnancy outcome, so heightened surveillance with genetic evaluation, serial growth scans and third-trimester assessment of wellbeing should be considered. PMD must be differentiated from gestational trophoblastic disease because management and outcomes differ.

Placental Mesenchymal Dysplasia

Placental mesenchymal dysplasia is a rare, incompletely understood placental stromal lesion, characterized by placentomegaly and striking ectasia and tortuosity of chorionic plate and stem villous vessels. Its prenatal ultrasonographic and gross pathologic features resemble those of a partial mole, but the fetus is typically normal and the placenta has a diploid, chromosomal complement. We discuss the pathologic features and current understanding of the etiopathogenesis of this condition, the supportive immunohistochemical and confirmatory molecular genetic studies important in its diagnosis, and its implications for pregnancy and infant outcomes.

Placentomegaly and placental mesenchymal dysplasia

A 23-year-old primigravida presented to the labour ward at 37 weeks gestation referred with intrauterine growth restriction, oligohydramnios and placentomegaly. Differential diagnoses of placentomegaly were considered. Her antenatal blood screening tests were normal. There were no fetal malformations. However, triple screen and fetal karyotype were not done as patient presented late in pregnancy. The patient soon went into spontaneous labour and delivered a girl weighing 2.15 kg with a normal Apgar score. The cord was long and twisted; placenta was bulky, 1.7 kg, with prominent grape-like vesicles involving whole placenta with a rim of normal placenta at the periphery. Microscopy showed some areas of multiple villi with marked hydropic changes and myxoid degeneration, preserved vasculature and no trophoblastic proliferation. Placental mesenchymal dysplasia was thus diagnosed. The baby had no evidence of Beckwith-Wiedemann syndrome. The child is now 3 years old with normal development and is doing well.

Placental mesenchymal dysplasia: a case report

Introduction. A rare case of histologically proven placental mesenchymal dysplasia (PMD) with fetal omphalocele in a 22-year-old patient is reported. Material and Methods. Antenatal ultrasound of this patient showed hydropic placenta with a live fetus of 17 weeks period of gestation associated with omphalocele. Cordocentesis detected the diploid karyotype of the fetus. Patient, when prognosticated, choose to terminate the pregnancy in view of high incidence of fetal and placental anomalies. Subsequent histopathological examination of placenta established the diagnosis to be placental mesenchymal dysplasia. Conclusion. On clinical and ultrasonic grounds, suspicion of P.M.D. arises when hydropic placenta with a live fetus presents in second trimester of pregnancy. Cordocentesis can detect the diploid karyotype of the fetus in such cases. As this condition is prognostically better than triploid partial mole, continuation of pregnancy can sometimes be considered after through antenatal screening and patient counseling. However, a definite diagnosis of P.M.D. is made only on placental histology by absence of trophoblast hyperplasia and trophoblastic inclusions.

Placental mesenchymal dysplasia: can early diagnosis ensure a good materno-foetal outcome? A case report

Placental mesenchymal dysplasia is a rare disorder characterized by an increased size placenta with cystic villi and ectasic vessels. The correct diagnosis is very important, because placental mesenchymal dysplasia is usually compatible with a normal foetal morphology and a good materno-foetal outcome. An accurate ultrasound evaluation can help in the identification of characteristic patterns associated to this trophoblastic disease, particularly to distinguish it from its main differential diagnosis, i.e. hydatidiform mole. We report an early second-trimester ultrasound diagnosis of placental mesenchymal dysplasia complicated by foetal growth restriction, but with normal female karyotype and good healthy baby.

Placental mesenchymal dysplasia

Placental mesenchymal dysplasia is a benign condition that can be confused with a molar pregnancy by ultrasound scanning and gross examination. Conservative management should be considered with a normal-appearing singleton fetus and a cystic-appearing placenta. We present a case of placental mesenchymal dysplasia with a favorable outcome.

Placental chorioangioma as the cause of non-immunologic hydrops fetalis; a case report

BACKGROUND

Chorioangiomas are the most common benign tumors of the placenta originating from primitive angioblastic tissues. It comprises near 1 percent of placental tumors. Clinical manifestations in the newborn are rare and usually associated with tumors greater than 5 cm in diameter and consist of polyhydramnios, fetal anemia, massive edema with pleural effusion, ascites and intrauterine growth retardation. We present a case with large chorioangioma as the cause of non-immunologic hydrops fetalis with a successful outcome.

CASE PRESENTATION

The patient was a female newborn with history of polyhydramnios, symptoms of congestive heart failure and associated anemia, thrombocytopenia and coagulopathy. The pathophysiology and management of the complications of hydrops fetalis with chorioangioma are discussed

CONCLUSION

Chorioangioma of the placenta has potentially serious perinatal risks and so the pregnancy needs to have regular surveillance. The chance of developing complications is directly related with the tumor size.