Placental mesenchymal dysplasia and an estimation of the population incidence

Placental mesenchymal dysplasia complicated with sudden fetal demise and amniotic fluid embolism: a case report

BACKGROUND

Placenta mesenchymal dysplasia (PMD) is a rare placental anomaly associated with various fetal and maternal complications. Whether close ultrasound surveillance can prevent intrauterine fetal demise (IUFD) in patients with PMD is still under investigation. Amniotic fluid embolism (AFE) is a rare, lethal, and unpredictable maternal complication that has never been described in association with PMD. Here, we report a case of PMD, in which the fetus eventually demised in utero despite weekly color Doppler monitoring, and the mother subsequently encountered AFE during delivery.

CASE PRESENTATION

A 43-year-old woman who had received three frozen embryo transfer, was found to have a singleton pregnancy with an enlarged multi-cystic placenta at 8 weeks' gestation. Fetal growth restriction (FGR) was noted since the 21^stweek. The fetus eventually demised in-utero at 25 weeks despite weekly color Doppler surveillance. Cesarean section was performed under general anesthesia due to placenta previa totalis and antepartum hemorrhage. During surgery, the patient experienced a sudden blood pressure drop and desaturation followed by profound coagulopathy. AFE was suspected. After administration of inotropic agents and massive blood transfusion, the patient eventually survived AFE. PMD was confirmed after pathological examination of the placenta.

CONCLUSIONS

While FGR can be monitored by color Doppler, our case echoed previous reports that IUFD may be unpreventable even under intensive surveillance in PMD cases. Although AFE is usually considered unpredictable, PMD can result in cumulative risk factors contributing to AFE. Whether a specific link exists between the pathophysiology of PMD and AFE requires further investigation.

Placental Mesenchymal Dysplasia and Beckwith-Wiedemann Syndrome

Placental mesenchymal dysplasia (PMD) is characterized by placentomegaly, aneurysmally dilated chorionic plate vessels, thrombosis of the dilated vessels, and large grapelike vesicles, and is often mistaken for partial or complete hydatidiform mole with a coexisting normal fetus. Androgenetic/biparental mosaicism (ABM) has been found in many PMD cases. Beckwith-Wiedemann syndrome (BWS) is an imprinting disorder with complex and diverse phenotypes and an increased risk of developing embryonal tumors. There are five major causative alterations: loss of methylation of imprinting control region 2 (KCNQ1OT1:TSS-DMR) (ICR2-LOM), gain of methylation at ICR1 (H19/IGF2:IG-DMR) (ICR1-GOM), paternal uniparental disomy of 11 (pUPD11), loss-of-function variants of the CDKN1C gene, and paternal duplication of 11p15. Additional minor alterations include genetic variants within ICR1, paternal uniparental diploidy/biparental diploidy mosaicism (PUDM, also called ABM), and genetic variants of KCNQ1. ABM (PUDM) is found in both conditions, and approximately 20% of fetuses from PMD cases are BWS and vice versa, suggesting a molecular link. PMD and BWS share some molecular characteristics in some cases, but not in others. These findings raise questions concerning the timing of the occurrence of the molecularly abnormal cells during the postfertilization period and the effects of these abnormalities on cell fates after implantation.

Prenatal Diagnosis of Placental Mesenchymal Dysplasia with 46, X, Isochromosome Xq/45, X Mosaicism

Placental mesenchymal dysplasia is an uncommon vascular anomaly of the placenta with characteristics of placentomegaly and multicystic appearance and with or without association with fetal chromosomal anomaly. We present a unique placental mesenchymal dysplasia patient with amniotic fluid karyotyping as 46, X, iso(X) (q10). Detailed molecular testing of the amniotic fluid, fetal cord blood, non-dysplastic placenta and dysplastic placenta was conducted after termination of pregnancy, from which we proved biparental/androgenetic (46, X, i(X) (q10)/45, X) mosaicism in different gestational tissues. A high portion of androgenetic cells in dysplastic placenta (74.2%) and near 100% of biparental cells in the fetus’s blood and amniotic fluid were revealed. Delicate mosaic analyses were performed, and possible pathogenesis and embryogenesis of this case were drawn up.

Sudden fetal death with placental mesenchymal dysplasia complicated by placenta previa

Placental mesenchymal dysplasia (PMD) is a rare placental abnormality that is closely related to severe pregnancy complications. A 27-year-old woman with fetal growth restriction and placenta previa was referred to a university hospital at 22 gestational weeks (GW). She was suspected of having a twin pregnancy with a complete or partial hydatidiform mole and coexisting normal live fetus, because two separate placentas, an enlarged one with multiple cystic lesions and a normal one, were shown on ultrasound examinations. At 27 GW, she experienced a sudden intrauterine fetal death (IUFD) after bleeding due to placenta previa, despite confirmation of fetal well-being at 2 h before bleeding. After delivery, histopathological examination confirmed the diagnosis of PMD. This is the first documented case of a woman with PMD and placenta previa who had a sudden IUFD after bleeding. Patients with both PMD and placenta previa should be considered at extremely high risk for IUFD.

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.

[Placental mesenchymal dysplasia]

OBJECTIVE

To carry out a clinical and morphological analysis of 6 cases of placental mesenchymal dysplasia (PMD) that is not associated with Beckwith-Wiedemann syndrome.

MATERIAL AND METHODS

Medical records, placental macroscopic and microscopic changes, histochemical (MSB staining) and immunohistochemical studies of placental tissue with antibodies against p57, CD34, smooth muscle actin, desmin, and Ki-67 were analyzed.

RESULTS

Vascular anomalies in the chorionic plate and stem villi, the increased size and edema of the stem villi during normal formation of the terminal branches of the villous tree, the lack of proliferation of villous trophoblast were the typical signs of PMD and were noted in all cases. Comparison of the results of ultrasonography with the morphological pattern of the disease suggested that there were ultrasound signs that were typical of PMD. The characteristics of the course and outcomes of pregnancy in PMD were given. The features of morphological changes in the presence of PMD concurrent with preeclampsia were found. Significant variability in p57 expression in PMD was shown and variants of changes given. There were no substantial features of the expression of desmin and smooth muscle actin in PMD.

CONCLUSION

MDP has typical morphological and ultrasound signs. The significant variability in the levels of chorionic gonadotropin and alpha-fetoprotein and in the expression of p57 does not allow their use in the differential diagnosis of PMD. The high incidence of thrombotic events in the intervillous space and fetal vessels, as well as intrauterine growth restriction, intrauterine hypoxia, and an impaired neonatal adaptation period in PMD should be taken into account when determining the management tactics for female patients and newborns.

Cystic placentomegaly on a second-trimester ultrasound

Placental mesenchymal dysplasia (PMD) is a rare disorder of the placenta characterized by placentomegaly, cystic vesicles, and dilated chorionic blood vessels. Clinically and pathologically, it closely resembles partial molar pregnancy and complete hydatidiform mole with a coexistent healthy fetus, both of which are associated with malignant trophoblastic disease. PMD, however, has no risk of malignant trophoblastic disease and can result in the birth of a normal fetus, highlighting the need for clinician awareness of PMD in order to avoid unnecessary termination of a viable and potentially healthy fetus.

Anemia in a neonate with placental mesenchymal dysplasia

Causes of intrauterine fetal death (IUFD) are uncertain in most placental mesenchymal dysplasia (PMD) cases. Our case showed high α‐fetoprotein levels in the maternal circulation, markedly dilated subchorionic vessels, and neonatal hemoglobin concentration of 8.4 g/dL, suggesting that fetal anemia may explain some adverse outcomes in PMD pregnancies.

[Placental mesenchymal dysplasia: consequences for the newborn]

CASE REPORT

We report the case of a newborn presenting with anemia, thrombopenia, intrauterine growth restriction (IUGR), and hepatic hemangioma revealing placental mesenchymal dysplasia.

CONCLUSION

This rare disease is not always diagnosed during pregnancy. Placental chorioangioma is responsible (in the absence of lethal complications in utero) for IUGR, anemia, neonatal thrombopenia, and hepatic or cutaneous hemangiomas. The early search for hemangiomas with ultrasound scanning could be useful to predict cardiac failure by left-to-right shunt.

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.