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Introduction: Placental mesenchymal dysplasia (PMD) is a benign lesion that is often misdiagnosed as complete (CHM) or partial hydatidiform mole. PMD usually results in live birth but can be associated with several fetal defects. Herein, we report PMD with CHM in a singleton placenta with live birth. Case Presentation: A 34-year-old gravida 2, para 1, living 1 (G2P1L1) woman was referred on suspicion of a molar pregnancy in the first trimester. Maternal serum human chorionic gonadotrophin levels were increased during early pregnancy, with multicystic lesions and placentomegaly observed on ultrasonography. Levels decreased to normal with no fetal structural abnormalities observed. A healthy male infant was delivered at 34 gestational weeks. Placental p57KIP2 immunostaining and short tandem repeat analysis revealed three distinct histologies and genetic features: normal infant and placenta, PMD, and CHM. Gestational trophoblastic neoplasia was diagnosed and up to fourth-line chemotherapy administered. Conclusion: Distinguishing PMD from hydatidiform moles is critical for avoiding unnecessary termination of pregnancy. CHM coexisting with a live fetus rarely occurs. This case is unique in that a healthy male infant was born from a singleton placenta with PMD and CHM. [ABSTRACT FROM AUTHOR]

Background: Placental mesenchymal dysplasia (PMD) is a rare placental disease of poorly understood etiology. It is characterized by aneurysmal dilatation of the chorionic blood vessels, mesenchymal proliferation, and myxomatous degeneration of the stem villi. Although it shares radiological and gross pathological features with partial hydatidiform mole, PMD doesn't necessitate termination of pregnancy. Case presentation: A 20-year-old woman presented at 25 weeks of gestation with profuse vaginal bleeding and loss of sensation of fetal movements. Abdominal ultrasound revealed a dead fetus and a markedly thick placenta which contains frequent hypoechoic cystic spaces creating a Swiss cheese appearance. Serum β-HCG was within the normal range as regards the gestational stage. A gross examination of the placenta revealed dilated tortuous blood vessels with frequent aneurysms on the placental surface and the cut section showed clotted blood. No definite vesicles were seen. Histopathological evaluation of the placental tissue revealed a mixture of normal and dilated villi with thick chorionic blood vessels and myxomatous degeneration of the villous cores. There was no trophoblastic proliferation, features were kept with PMD. Conclusion: Placental mesenchymal dysplasia is a rare placental disease that is usually confused with partial hydatidiform mole at both radiological and gross pathological features. However, histopathological examination helps in adopting an accurate diagnosis.

Abstract 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 21stweek. 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.

Abstract Background Although infantile hepatic hemangioma and hepatic mesenchymal hamartoma are relatively common in benign pediatric liver tumors, coexistence of the two tumors is rare. Placental mesenchymal dysplasia is also a rare disorder. We report the case of a baby girl born after a pregnancy complicated by placental mesenchymal dysplasia, who developed both infantile hepatic hemangioma and hepatic mesenchymal hamartoma. Case presentation The patient was born at 32 weeks and 5 days of gestation for impending placental abruption, weighing 1450 g. Liver tumors, composed of both hypervascular solid and large cystic lesions, were detected after birth and markedly increased to create abdominal distention within 9 months. Diagnostic imaging suspected the coexistence of infantile hepatic hemangioma and cystic hepatic mesenchymal hamartoma. Following propranolol therapy for infantile hepatic hemangioma and needle puncture of a large cyst, the cystic lesions and adjacent hypervascular lesions were partially resected via laparotomy. Pathological findings confirmed the coexistence of hepatic mesenchymal hamartoma and infantile hepatic hemangioma, which had no association with androgenetic/biparental mosaicism. The postoperative course was uneventful, and the tumor had not regrown after 3 years. Conclusions Although the coexistence of infantile hepatic hemangioma and hepatic mesenchymal hamartoma associated with placental mesenchymal dysplasia is extremely rare, the pathological and pathogenetic similarities between these disorders suggest that they could have derived from similar embryologic origins rather than being a mere coincidence. Further follow-up is required, with careful attention to the potential for malignant hepatic mesenchymal hamartoma transformation.

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 21stweek. 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. [ABSTRACT FROM AUTHOR]

Background: Placental mesenchymal dysplasia (PMD) is a rare placental disease of poorly understood etiology. It is characterized by aneurysmal dilatation of the chorionic blood vessels, mesenchymal proliferation, and myxomatous degeneration of the stem villi. Although it shares radiological and gross pathological features with partial hydatidiform mole, PMD doesn't necessitate termination of pregnancy. Case presentation: A 20-year-old woman presented at 25 weeks of gestation with profuse vaginal bleeding and loss of sensation of fetal movements. Abdominal ultrasound revealed a dead fetus and a markedly thick placenta which contains frequent hypoechoic cystic spaces creating a Swiss cheese appearance. Serum β-HCG was within the normal range as regards the gestational stage. A gross examination of the placenta revealed dilated tortuous blood vessels with frequent aneurysms on the placental surface and the cut section showed clotted blood. No definite vesicles were seen. Histopathological evaluation of the placental tissue revealed a mixture of normal and dilated villi with thick chorionic blood vessels and myxomatous degeneration of the villous cores. There was no trophoblastic proliferation, features were kept with PMD. Conclusion: Placental mesenchymal dysplasia is a rare placental disease that is usually confused with partial hydatidiform mole at both radiological and gross pathological features. However, histopathological examination helps in adopting an accurate diagnosis. [ABSTRACT FROM AUTHOR]

Simple Summary: Placental mesenchymal dysplasia (PMD) is a morphological abnormality resembling partial hydatidiform moles without abnormal trophoblastic proliferation. In PMD, approximately 20% of fetuses have Beckwith–Wiedemann syndrome (BWS), and approximately 20% of BWS fetuses are associated with PMD. In addition, PMD is a cardinal feature of BWS, and paternal uniparental diploidy/biparental diploidy mosaicism (also called androgenetic/biparental mosaicism) has been found in both BWS and PMD. This suggests that there is a molecular link between BWS and PMD. In this review, we focus on the etiologies of BWS and PMD and describe the molecular link between them. Both conditions are imprinting disorders that, depending on the case, may share or differ in molecular characteristics. These observations 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. 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. [ABSTRACT FROM AUTHOR]

Background: Although infantile hepatic hemangioma and hepatic mesenchymal hamartoma are relatively common in benign pediatric liver tumors, coexistence of the two tumors is rare. Placental mesenchymal dysplasia is also a rare disorder. We report the case of a baby girl born after a pregnancy complicated by placental mesenchymal dysplasia, who developed both infantile hepatic hemangioma and hepatic mesenchymal hamartoma. Case presentation: The patient was born at 32 weeks and 5 days of gestation for impending placental abruption, weighing 1450 g. Liver tumors, composed of both hypervascular solid and large cystic lesions, were detected after birth and markedly increased to create abdominal distention within 9 months. Diagnostic imaging suspected the coexistence of infantile hepatic hemangioma and cystic hepatic mesenchymal hamartoma. Following propranolol therapy for infantile hepatic hemangioma and needle puncture of a large cyst, the cystic lesions and adjacent hypervascular lesions were partially resected via laparotomy. Pathological findings confirmed the coexistence of hepatic mesenchymal hamartoma and infantile hepatic hemangioma, which had no association with androgenetic/biparental mosaicism. The postoperative course was uneventful, and the tumor had not regrown after 3 years. Conclusions: Although the coexistence of infantile hepatic hemangioma and hepatic mesenchymal hamartoma associated with placental mesenchymal dysplasia is extremely rare, the pathological and pathogenetic similarities between these disorders suggest that they could have derived from similar embryologic origins rather than being a mere coincidence. Further follow-up is required, with careful attention to the potential for malignant hepatic mesenchymal hamartoma transformation. [ABSTRACT FROM AUTHOR]

Introduction Placental mesenchymal dysplasia (PMD) is often associated with Beckwith-Wiedemann syndrome. Case report: A 27-year-old woman with preeclampsia prematurely delivered twin girls. One side of the placenta was larger with numerous grape-like vesicles, histologically with large, cystic, stem villi with cisterns without syncytiotrophoblastic hyperplasia. This side showed mosaicism for chromosome 11 by FISH and hypomethylation at ICR2 by MLPA. The smaller side of the placenta was normal macroscopically, microscopically, and karyotypically. There was symmetric growth restriction, macroglossia and hypoglycemia of the girl corresponding to the abnormal placental side, and lesser symmetric growth restriction and mild hypoglycemia in the other girl. Conclusion: Localized placental mesenchymal dysplasia can occur in monochorionic diamniotic twin placenta with Beckwith-Wiedemann syndrome. Fetal affects may be asymmetric. PMD can be associated with mosaicism monosomy of chromosome 11. [ABSTRACT FROM AUTHOR]

Abstract Background Hydatidiform moles exhibit a distinctive gross appearance of multiple vesicles in the placenta. The advances in cytogenetic technologies have helped uncover novel entities of hydatidiform moles and enabled elaborate diagnoses. However, management of a vesicular placenta with a coexistent live fetus poses a bigger challenge beyond hydatidiform moles. Case presentation A 33-year-old woman was referred to our department for suspected hydatidiform mole coexistent with a live fetus at 24 weeks’ gestation. The patient had conceived through double embryo transplantation, and first-trimester ultrasonography displayed a single sac. Mid-trimester imaging findings of normal placenta parenchyma admixed with multiple vesicles and a single amniotic cavity with a fetus led to suspicion of a singleton partial molar pregnancy. After confirmation of a normal diploid by amniocentesis and close surveillance, the patient delivered a healthy neonate. Preliminary microscopic examination of the placenta failed to clarify the diagnosis until fluorescence in situ hybridization showed a majority of XXY sex chromosomes. The patient developed suspected choriocarcinoma and achieved remission for 5 months after chemotherapy, but relapsed with suspected intermediate trophoblastic tumor. Conclusion We report a rare case of twin pregnancy comprising a partial mole and a normal fetus that resembled a singleton partial molar pregnancy. Individualized care is important in conditions where a vesicular placenta coexists with a fetus. We strongly recommend ancillary examinations in addition to traditional morphologic assessment in such cases.

Background: Placental mesenchymal dysplasia (PMD) is a morphological abnormality resembling partial hydatidiform moles. It is often associated with androgenetic/biparental mosaicism (ABM) and complicated by Beckwith–Wiedemann syndrome (BWS), an imprinting disorder. These phenomena suggest an association between PMD and aberrant genomic imprinting, particularly of CDKN1C and IGF2. The existence of another type of PMD containing the biparental genome has been reported. However, the frequency and etiology of biparental PMD are not yet fully understood. Results: We examined 44 placental specimens from 26 patients with PMD: 19 of these were macroscopically normal and 25 exhibited macroscopic PMD. Genotyping by DNA microarray or short tandem repeat analysis revealed that approximately 35% of the macroscopic PMD specimens could be classified as biparental, while the remainder were ABM. We performed a DNA methylation analysis using bisulfite pyrosequencing of 15 placenta-specific imprinted differentially methylated regions (DMRs) and 36 ubiquitous imprinted DMRs. As expected, most DMRs in the macroscopic PMD specimens with ABM exhibited the paternal epigenotype. Importantly, the biparental macroscopic PMD specimens exhibited frequent aberrant hypomethylation at seven of the placenta-specific DMRs. Allelic expression analysis using single-nucleotide polymorphisms revealed that five imprinted genes associated with these aberrantly hypomethylated DMRs were biallelically expressed. Frequent aberrant hypomethylation was observed at five ubiquitous DMRs, including GRB10 but not ICR2 or ICR1, which regulate the expression of CDKN1C and IGF2, respectively. Whole-exome sequencing performed on four biparental macroscopic PMD specimens did not reveal any pathological genetic abnormalities. Clinical and molecular analyses of babies born from pregnancies with PMD revealed four cases with BWS, each exhibiting different molecular characteristics, and those between BWS and PMD specimens were not always the same. Conclusion: These data clarify the prevalence of biparental PMD and ABM-PMD and strongly implicate hypomethylation of DMRs in the pathogenesis of biparental PMD, particularly placenta-specific DMRs and the ubiquitous GRB10, but not ICR2 or ICR1. Aberrant hypomethylation of DMRs was partial, indicating that it occurs after fertilization. PMD is an imprinting disorder, and it may be a missing link between imprinting disorders and placental disorders incompatible with life, such as complete hydatidiform moles and partial hydatidiform moles. [ABSTRACT FROM AUTHOR]

Placental mesenchymal dysplasia (PMD) is a rare disorder of the placenta characterized by placentomegaly with diffuse hydropic stem villous, aneurysmally dilated vessels, and lack of trophoblastic proliferation. Case: The prenatal ultrasound of a 34-year-old woman (G1P0) at 33 weeks of gestation showed an enlarged placenta with multiple cystic lesions, heterogeneous echoes with no active blood flow, and fetal growth restriction (FGR). The differential diagnosis involved partial mole, placental hemorrhage, and PMD. She developed preeclampsia at 38 weeks of gestation and gave birth to a normally formed, growth-restricted baby. The placenta, weighing 785 g, showed scattered cystic vesicles in the parenchyma. The histology shows enlarged edematous stem villi with occasional cistern formation and no area of chorioangioma or features of molar pregnancy. PMD associated fetal growth restriction was diagnosed. Conclusion: PMD has prenatal ultrasound result resembling those of partial mole, placental hemorrhage and chorioangioma, but the fetus is phenotypically normal. Nevertheless, fetal surveillance is essential.

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. [ABSTRACT FROM AUTHOR]

Background: Numerous hypoechoic cysts in the placenta on prenatal ultrasonography with a live fetus may indicate twin pregnancy with a complete hydatidiform mole with a coexistent fetus, partial mole, confined placental mosaicism, or placental mesenchymal dysplasia (PMD). Ultrasonographic appearances of these are similar; however, the differential diagnosis should be made because maternal and fetal prognoses differ. Cases: We present two cases of twin pregnancies with numerous placental cystic lesions. The first case was a partial hydatidiform mole in monochorionic diamniotic twins with a diploid karyotype that underwent a spontaneous abortion at 20 gestational weeks. The second case was PMD in dichorionic diamniotic twins; live twin neonates were delivered at 34 gestational weeks. Emergency cesarean section delivery was performed due to severe preeclampsia and fetal growth restriction in twin A at 34 weeks of gestation. Conclusions: Numerous hypoechoic cysts in the placenta on prenatal ultrasonography with a normal live fetus warrants chromosomal analysis and serial ultrasonographic examination to differentiate between PMD and molar pregnancy with a coexisting normal fetus to avoid unnecessary termination.

Background: Hydatidiform moles exhibit a distinctive gross appearance of multiple vesicles in the placenta. The advances in cytogenetic technologies have helped uncover novel entities of hydatidiform moles and enabled elaborate diagnoses. However, management of a vesicular placenta with a coexistent live fetus poses a bigger challenge beyond hydatidiform moles.Case Presentation: A 33-year-old woman was referred to our department for suspected hydatidiform mole coexistent with a live fetus at 24 weeks' gestation. The patient had conceived through double embryo transplantation, and first-trimester ultrasonography displayed a single sac. Mid-trimester imaging findings of normal placenta parenchyma admixed with multiple vesicles and a single amniotic cavity with a fetus led to suspicion of a singleton partial molar pregnancy. After confirmation of a normal diploid by amniocentesis and close surveillance, the patient delivered a healthy neonate. Preliminary microscopic examination of the placenta failed to clarify the diagnosis until fluorescence in situ hybridization showed a majority of XXY sex chromosomes. The patient developed suspected choriocarcinoma and achieved remission for 5 months after chemotherapy, but relapsed with suspected intermediate trophoblastic tumor.Conclusion: We report a rare case of twin pregnancy comprising a partial mole and a normal fetus that resembled a singleton partial molar pregnancy. Individualized care is important in conditions where a vesicular placenta coexists with a fetus. We strongly recommend ancillary examinations in addition to traditional morphologic assessment in such cases. [ABSTRACT FROM AUTHOR]

We report a case of a singleton hydrops pregnancy with placental gross and microscopic features between partial hydatidiform mole (PHM) and placental mesenchymal dysplasia (PMD) in a diploid live fetus. Pregnancy was complicated by early onset of growth restriction and pre‐eclampsia. A female newborn was born at 29 weeks with no congenital malformations. Histology of the placenta revealed mixed phenotype of PMD and PHM, and genetic test results were normal. [ABSTRACT FROM AUTHOR]

To identify the differentiating features in clinical presentation, management, and maternal/fetal outcome in complete hydatidiform mole and coexistent fetus compared with placental mesenchymal dysplasia.Between 1997 and 2015, five women with complete hydatidiform mole and coexistent fetus and four women with placental mesenchymal dysplasia were managed at the University of California San Francisco. Clinical features were analyzed and compared with previously published data.Of the five cases of complete hydatidiform mole and coexistent fetus, two had live births. β-hCG levels were > 200,000 IU/L in all cases. On imaging, a clear plane between the cystic component and the placenta favored a diagnosis of complete hydatidiform mole and coexistent fetus. None of the patients went on to develop gestational trophoblastic neoplasia (GTN), with a range of follow-up from 2 to 38 months. Combining this data with previously published work, the live birth rate in these cases was 38.8%, the rate of persistent GTN was 36.2%, and the rate of persistent GTN in patients with reported live births was 27%. Of the four cases of placental mesenchymal dysplasia, all four had live births. One patient developed HELLP syndrome and intrauterine growth restriction; the remaining three were asymptomatic.Maternal symptoms, fetal anomalies, β-hCG level, and placental growth pattern on imaging may help differentiate between complete hydatidiform mole and coexistent fetus and placental mesenchymal dysplasia. There was not an increased risk of gestational trophoblastic neoplasia in patients with complete hydatidiform mole and coexistent fetus who opted to continue with pregnancy.

Aim: This study aimed to evaluate the clinical features and pregnancy outcomes of placental mesenchymal dysplasia (PMD) in Japan. Methods: We requested detailed clinical information and placental tissue of PMD cases in 2000–2018 from Japanese facilities with departments of obstetrics and gynecology and analyzed the pregnancy course and neonatal outcomes. Results: We collected 49 cases of PMD. Of 18 patients with measured maternal serum alpha‐fetoprotein (MSAFP) levels, 15 (83.3%) had elevated levels. Maternal serum human chorionic gonadotropin (MShCG) levels were transiently elevated in five (17.8%) of 28 patients. Forty‐seven patients continued their pregnancies. All pregnancies were singleton and 40 (85.1%) were associated with adverse events including fetal growth restriction (FGR), threatened premature delivery, fetal demise, and hypertensive disorder of pregnancy in 34 (72.3%), 14 (29.8%), eight (17.0%), and six (12.8%) patients, respectively. Of 47 infants, there were eight stillbirths. There were 40 (85.1%) female infants, and eight (17.0%) had Beckwith–Wiedemann syndrome. Of 39 live births, 23 (59.0%) were associated with premature induction of labor or cesarean section for obstetric indications related to FGR. Eighteen (46.2%) neonates had complications. PMD‐affected placentas were pathologically heterogeneous in both grossly PMD‐affected and non‐affected areas. Conclusions: Our study included the largest number of PMD cases with detailed clinical information. PMD is a high‐risk condition for both the mother and the child. Elevated MSAFP levels with normal MShCG levels indicate PMD. Conventional perinatal management of FGR in Japan might be effective in reducing the fetal mortality rate. [ABSTRACT FROM AUTHOR]

Detailed clinical and pathological features of placental mesenchymal dysplasia (PMD) complicated by preeclampsia (PE) are unknown. A 39-year-old nulliparous woman was referred at 19 weeks gestation. Ultrasound examination identified a fetus with severe growth restriction (−2.8 SD) and a markedly thickened placenta with many cystic structures suggestive of PMD. At 21 weeks, the patient developed severe hypertension (180/95 mm Hg) with marked proteinuria and an elevated serum soluble fms-like tyrosine-kinase-1 (sFlt-1) level (47,000 pg/L). The pregnancy was terminated to protect maternal health. Placental weight was 450 g and no histopathological findings of either proliferation or dysplasia were observed in the trophoblast. Villous chromosome examination revealed a 46XX karyotype, consistent with the diagnosis of PMD. In addition to the pathological findings of vascular endothelial dysfunction characteristic of the placenta in PE cases, enhanced expression of sFlt-1 in the syncytiotrophoblast of the enlarged villi was confirmed by immunohistochemistry as a novel finding in this condition. Monitoring of the serum sFlt-1 value is suggested to be a useful predictor of the pathological change associated with extremely early severe PE in PMD cases.

We describe a 22-year-old woman (2-gravid) case who was referred to our clinic at 18 weeks of gestation for a placenta with vesicular lesions discovered on prenatal examination routine. An ultrasound exam at 31 weeks of gestation showed numerous vesicular lesions, which gradually augmented as the pregnancy advanced. A live normal-appearing fetus was confirmed by intrauterine growth restriction (IUGR). The maternal serum β-human chorionic gonadotropin level remained in normal ranges. At some point, a multidisciplinary medical consensus considered the termination of the pregnancy, but the patient refused to comply. At 33 weeks of gestation, preterm premature rupture of membranes (pPROM) occurred, and she spontaneously delivered a 1600 g healthy female baby with a good long-term outcome. Placental mesenchymal dysplasia (PMD) was retrospectively diagnosed after confronting the data from ultrasound, chorionic villus sampling (CVS), amniocentesis, pathological examination, and immunohistochemical stain. The lack of sufficient reports of PMD determines doctors to be cautious and reserved, approaching these cases more radically than necessary. We reviewed this disease and searched for all cases of PMD associated with healthy, live newborns.

Placental mesenchymal dysplasia is an increasingly recognizable abnormality. Early cases have been confused with partial hydatidiform mole. Placental mesenchymal dysplasia is probably under-diagnosed because of being an unfamiliar clinical entity and also mistaken for gestational trophoblastic disease due to the similar sonographic findings of two entities. In this report, we describe the clinical, gross, and histopathological findings of placental mesenchymal dysplasia in two cases. The 33-week-preterm baby of a 26-year-old woman with cardiovascular disease and 342 gram placenta and the 19-week fetus with trisomy 21 of a 40 year-old woman were terminated. Macroscopically thick-walled vessels and microscopically hydropic villous with peripherally localized thick-walled vessels without trophoblastic cell proliferation were observed in both cases. These two cases represent a rare placental anomaly that is benign but it is challenging to distinguish placental mesenchymal dysplasia from an incomplete mole. Placental mesenchymal dysplasia should be included in the differential diagnosis of sonographic findings that show a normal appearing fetus and a placenta with cystic lesions. Placental mesenchymal dysplasia is associated with pregnancy-related hypertension. In conclusion, the most important point is “you can diagnose it if you consider it”.

Placental mesenchymal dysplasia (PMD), characterized by an enlarged and thickened placenta with multiple hypoechoic cystic spaces, frequently leads to a poor infantile/fetal outcome. Here, we describe a case of PMD involving an infant delivered at term with a good outcome. The fetus was male, and the proportion of the PMD lesion to the entire placenta remained constant: the PMD lesion did not enlarge. Given what is known about the pathogenesis of PMD with its association with vascular endothelial growth factor‐D (VEGF‐D) encoded by an X‐linked gene and androgenetic/biparental mosaicism, which is consistent with female dominancy and a poor outcome, we suggest that a male sex of the fetus and non‐progressing PMD may have been associated with this good outcome. [ABSTRACT FROM AUTHOR]

Placental mesenchymal dysplasia (PMD) and partial hydatidiform mole (PHM) placentas share similar characteristics, such as placental overgrowth and grape-like placental tissues. Distinguishing PMD from PHM is critical because the former can result in normal birth, while the latter diagnosis will lead to artificial abortion. Aneuploidy and altered dosage of imprinted gene expression are implicated in the pathogenesis of PHM and also some of the PMD cases. Diandric triploidy is the main cause of PHM, whereas mosaic diploid androgenetic cells in the placental tissue have been associated with the formation of PMD. Here, we report a very special PMD case also presenting with trophoblast hyperplasia phenotype, which is a hallmark of PHM. This PMD placenta has a normal biparental diploid karyotype and is functionally sufficient to support normal fetal growth. We took advantage of this unique case to further dissected the potential common etiology between these two diseases. We show that the differentially methylated region (DMR) at NESP55, a secondary DMR residing in the GNAS locus, is significantly hypermethylated in the PMD placenta. Furthermore, we found heterozygous mutations in NLRP2 and homozygous variants in NLRP7 in the mother’s genome. NLRP2 and NLRP7 are known maternal effect genes, and their mutation in pregnant females affects fetal development. The variants/mutations in both genes have been associated with imprinting defects in mole formation and potentially contributed to the mild abnormal imprinting observed in this case. Finally, we identified heterozygous mutations in the X-linked ATRX gene, a known maternal–zygotic imprinting regulator in the patient. Overall, our study demonstrates that PMD and PHM may share overlapping etiologies with the defective/relaxed dosage control of imprinted genes, representing two extreme ends of a spectrum.

When placenta appears large on ultrasound, there are certain differential diagnoses to be kept in mind. We present a series of three cases in which large placenta was observed in first trimester scan. All three pregnancies resulted in Foetal Growth Restriction (FGR) associated with placental morphological abnormality.

Placental mesenchymal dysplasia (PMD) is a rare yet serious placental vascular abnormality featuring placental hypertrophy and grape‐like fluid‐filled spaces that can easily be misdiagnosed for other conditions, particularly molar pregnancy. It can be difficult to differentiate these entities with ultrasound alone; however, it is very important for sonographers to understand the difference between PMD and molar pregnancy, as each has a very different prognosis. This case report describes an enlarged placenta containing fluid‐filled spaces, a structurally and chromosomally normal fetus, PMD, and its differential diagnoses. [ABSTRACT FROM AUTHOR]

Biparental/androgenetic mosaicism is a rarely diagnosed condition in humans. It is typically ascertained prenatally on the basis of placental mesenchymal dysplasia. Fetal outcome can range from demise due to intrauterine growth retardation to term delivery. Most of the published cases of liveborns represent females that are either completely normal or have features of Beckwith‐Wiedemann syndrome. Only two healthy liveborn males with mosaicism detected in the placenta have been described to date. Here, we report another liveborn male with hepatic mesenchymal hamartoma, soft tissue overgrowth on his right fifth toe, hemangiomas over his chest, right buttock and foot, anemia, thrombocytopenia and congenital hypothyroidism with biparental/androgenetic mosaicism detected in the toe mass in addition to the placenta. This new case adds to the existing literature of individuals with biparental/androgenetic mosaicism and expands the range of clinical presentations that may be seen in male patients with this condition. This study also illustrates the important use of single‐nucleotide polymorphism microarray in conjunction with short‐tandem repeat analysis on affected tissue to provide a diagnosis for patients with features of overgrowth and prior, non‐diagnostic, genetic analyses of their peripheral blood. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the frequency of placental pathological lesions in Beckwith-Wiedemann syndrome (BWS), an overgrowth disorder that exhibits etiologic molecular heterogeneity and variable phenotypic expression. Materials and methods: The study included 60 BWS patients with a proven molecular diagnosis and a placental pathological examination. Placentomegaly, placental mesenchymal dysplasia (PMD), chorangioma/chorangiomatosis, and extravillous trophoblastic (EVT) cytomegaly were evaluated and their frequencies in the different molecular subgroups were compared. Immunohistochemistry and fluorescent in situ hybridization (FISH) were performed on EVT cytomegaly. Results: Placentomegaly was found in 70.9% of cases, PMD in 21.7%, chorangioma/chorangiomatosis in 23.3%, and EVT cytomegaly in 21.7%; there was no significant intergroup difference. EVT cytomegaly showed loss of p57 expression, increased Ki67 proliferating index, and polyploidy on FISH analysis. Conclusions: There was no genotype/epigenotype-phenotype correlation concerning placental lesions in BWS. Diffuse EVT cytomegaly with polyploidy may represent a placental finding suggestive of BWS. [ABSTRACT FROM AUTHOR]

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.

Key Clinical Message: Placental mesenchymal dysplasia (PMD) occurs in about 1 in 5000 pregnancies. The differential diagnosis between PMD and partial mole is difficult on ultrasound scan, and karyotyping plays a key role in distinguishing PMD from partial mole. Our report is the first to report on the discordancy for PMD in a monochorionic setting. [ABSTRACT FROM AUTHOR]

Abstract: We report a rare case of placental mesenchymal dysplasia (PMD) with fetal growth restriction (FGR) in one placenta of a dichorionic diamniotic (DD) twin pregnancy. A 24‐year‐old woman was referred to our hospital at 24 weeks’ gestation due to FGR and ipsilateral placental abnormality in DD twins. Ultrasound and magnetic resonance imaging showed one placenta of the FGR fetus was bulky and had multiple cysts, while the other fetus placenta appeared normal. Cesarean section was performed at 32 weeks’ gestation; the first and second neonates weighted 1799 and 1215 g, respectively. Macroscopically, chorionic vessels on the placental surface of the second neonate were prominently enlarged. Pathological findings demonstrated swelling stem villi with enlarged vessels and increased interstitial cells without trophoblast proliferation. Immunostaining for p57kip2 was negative in interstitial cells and cytotrophoblasts of the swelling stem villi. This suggested that PMD occurred in one placenta of the DD twin, leading to early‐onset FGR. [ABSTRACT FROM AUTHOR]

Placental mesenchymal dysplasia is an increasingly recognizable abnormality. Early cases have been confused with partial hydatidiform mole. Placental mesenchymal dysplasia is probably under-diagnosed because of being an unfamiliar clinical entity and also mistaken for gestational trophoblastic disease due to the similar sonographic findings of two entities. In this report, we describe the clinical, gross and histopathological findings of placental mesenchymal dysplasia in two cases. The 33-week-preterm baby of a 26-year-old woman with cardiovascular disease and 342 gram placenta and the 19-week fetus with trisomy 21 of a 40 year-old woman were terminated. Macroscopically thick-walled vessels and microscopically hydropic villous with peripherally localized thick-walled vessels without trophoblastic cell proliferation were observed in both cases. These two cases represent a rare placental anomaly that is benign but it is challenging to distinguish placental mesenchymal dysplasia from an incomplete mole. Placental mesenchymal dysplasia should be included in the differential diagnosis of sonographic findings that show a normal appearing fetus and a placenta with cystic lesions. Placental mesenchymal dysplasia is associated with pregnancy-related hypertension. In conclusion, the most important point is "you can diagnose it if you consider it". [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Objective: This paper aims to present molecular cytogenetic and epigenetic evaluation of placental mesenchymal dysplasia (PMD). Materials and methods: A 33-year-old woman was referred to the hospital at 18 weeks of gestation because of a multicystic mass in the placenta. Ultrasound showed a normal amount of amniotic fluid and a normal singleton fetus. Amniocentesis revealed a karyotype of 46,XX. Array comparative genomic hybridization analysis of amniocytes revealed no genomic imbalance. Preterm labor and premature rupture of the membranes occurred, and a female fetus was delivered with no structural abnormality. The placenta was enlarged and filled with many grape-like vesicles. In the placental cystic mass, interphase fluorescence in situ hybridization revealed diploidy and array comparative genomic hybridization revealed no genomic imbalance. Quantitative fluorescent polymerase chain reaction (QF-PCR), methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA), and methylation-specific PCR were performed in the placental cystic mass. Results: MS-MLPA analysis showed hypermethylation (methylation index = 0.8) at H19 differentially methylated region (DMR) [imprinting center 1 (IC1)] at 11p15.5 and hypomethylation (methylation index = 0.2) at KvDMR1(IC2) at 11p15.5. Methylation-specific PCR assay identified hypomethylation of PEG1/MEST at 7q32, and hypermethylation at H19DMR and hypomethylation at KvDMR1 at 11p15.5. QF-PCR analysis identified androgenetic/biparental mosaicism in the placenta. The placental cystic mass was consistent with the diagnosis of PMD. Conclusion: MS-MLPA and methylation-specific PCR are useful methods for rapid detection of epigenetic alternations in PMD, and QF-PCR is useful in the diagnosis of androgenetic/biparental mosaicism.

A rare case of placental mesenchymal dysplasia (PMD) in a 26-year-old patient is reported. Ultrasound scan at 17 weeks of gestation showed placenta with multiple cystic spaces and a normal appearing fetus. Following delivery of a term live baby, histological examination of the placenta was suggestive of PMD. The early recognition of this rare condition by characteristic ultrasonographic findings is herein emphasized and hence that PMD is distinguished from molar pregnancy.

Introduction: The genetics and pathology of diploid complete and triploid partial hydatidiform moles have been well established. Enlarged cystic placenta often indicates an underlying etiology and is frequently associated with adverse pregnancy outcome. Several imprinted genes are strongly expressed in placental tissues and essential for normal placental growth and development. Disruption of these imprinted genes can lead to abnormal placental pathology and placental stunting or overgrowth. We present the genetic etiologies of five unusual mosaic cases of enlarged cystic placentas and report a novel etiology, mosaicism for deletion of the maternal GRB10 gene.Methods: Five mosaic placental mesenchymal dysplasia cases with discrete populations of "cystic" and "normal" villi and/or atypical p57KIP2 immunostaining were evaluated by genetic analysis; including G-banded karyotyping, fluorescence in situ hybridization (FISH), whole genome CGH + SNP microarray, conventional Sanger sequencing, and STR microsatellite analysis.Results: Genetic etiologies ranged from genome-wide changes, including mosaic androgenetic isodisomy and mosaic diandric triploidy, to a novel microdeletion of the maternally-expressed GRB10 gene. An abnormal mosaic population of cells was also detected in the fetus in two cases.Discussion: Four cases were mosaic for either diandric triploidy or an androgenetic cell population, and the enlarged cystic placentas were likely due to an excess of paternally-expressed growth promoting genes and also the absence of maternally-expressed growth restricting genes. Also we identified mosaicism for a novel microdeletion of the maternal GRB10 allele, a potent growth inhibitor, which resulted in placental overgrowth in the cystic area of one placenta. We advocate the use of ancillary techniques to investigate complex mosaic cases of enlarged cystic placentas to discover atypical genetic etiologies and to increase our understanding of the placental genome. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

When placenta appears large on ultrasound, there are certain differential diagnoses to be kept in mind. We present a series of three cases in which large placenta was observed in first trimester scan. All three pregnancies resulted in Foetal Growth Restriction (FGR) associated with placental morphological abnormality. [ABSTRACT FROM AUTHOR]

Aim Women with pre-eclampsia (PE), placenta previa (PP), placental abruption (PA), and placental mesenchymal dysplasia (PMD) have been described as having placental permeability dysfunction. This study was performed to determine whether occult fetomaternal hemorrhage (FMH) is common in women with such complications and in women with non-reassuring fetal status. Methods Forty-one antenatal and 39 postnatal blood samples were obtained from 46 women, including 11 with placental permeability dysfunction (5, 3, 2, and 1 with PE, PP, PA, and PMD, respectively) and 35 controls without such complications. To estimate the amount of fetal red blood cells, flow cytometry was performed using the fetal cell count system with two antibodies against fetal hemoglobin and carbonic anhydrase and the β-γ system with two monoclonal antibodies against hemoglobin β-chain and hemoglobin γ-chain. A diagnosis of FMH was made when the fraction size of the isolated cell population on scatter plots expressing fetal hemoglobin alone or hemoglobin γ-chain alone accounted for ≥0.02% of the total cell population on scatter plots. Results FMH was identified in five women, including one each with PE, PA, PP, PMD, and no complications. Thus, the prevalence rate of FMH was significantly higher in women with complications than in controls (36% [4/11] vs 2.9% [1/35], respectively, P = 0.009). The FMH occurrence rate did not differ between women with and without non-reassuring fetal status (7.7% [1/13] vs 12% [4/33], respectively, P = 1.000). Conclusion The risk of fetal red blood cells trafficking into the maternal circulation may be increased in women complicated with PE, PA, PP, and PMD. [ABSTRACT FROM AUTHOR]

Reportamos el primer caso en Chile de displasia mesenquimática placentaria que coexistió con un feto sano y cuyo curso clínico demostró un exitoso resultado perinatal. Se revisa la literatura y se definen las claves del diagnóstico diferencialThe first case in Chile of placental mesenchymal dysplasia is reported. The abnormal placenta coexisted with a normal fetus and the clinical course demostrated a successful perinatal outcome. The literature is reviewed and the keys of differential diagnoses are defined

Placental mesenchymal dysplasia (PMD) is a recently recognized, rare placental vascular anomaly characterized by placentomegaly and grape-like vesicles mimicking partial molar pregnancy. It is associated with significant fetal morbidity and mortality. We describe the histologic features of PMD in two different cases with different disease outcomes, one in a preterm intrauterine death (IUD) and another in a live birth. Placental examination in both the cases revealed large placenta with multiple vesicles and mesenchymal dysplasia.

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. [ABSTRACT FROM PUBLISHER]

We report a dichorionic twin gestation with diffuse placenta] mesenchymal dysplasia (PMD) and androgenetic biparental mosaicism (ABM) involving one twin's placenta with complete absence of fetal development for that twin. To our knowledge, this is the 1st reported case of PMD without fetal development. We discuss the gross, histologic, and genetic hallmarks of PMD and the spectrum of variability depending on degree and distribution of ABM. [ABSTRACT FROM AUTHOR]

Placental mesenchymal dysplasia ( PMD) is a rare disease that may be difficult to distinguish from molar pregnancy. The disease is associated with major fetal complications, including Beckwith- Wiedemann syndrome, fetal growth restriction and intrauterine fetal death. Rarely, fetal hematological disorders and liver tumors also may occur. Two patients were referred to our hospital during their second trimesters because of suspected molar pregnancies. Fetal karyotyping and maternal serum human chorionic gonadotropin level determinations led to the PMD diagnoses. In one case, the maternal clinical course was normal, but the neonate suffered from disseminated intravascular coagulation and needed a platelet transfusion. In the second case, the PMD decreased during pregnancy, but a gradually increasing fetal liver tumor appeared. The tumor was diagnosed as mesenchymal hamartoma, based on ultrasound and magnetic resonance imaging studies. The neonate was delivered without cardiovascular compromise. Due to the difficulty of immediate surgical treatment, expectant management, with close follow-up, was chosen. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Placental mesenchymal dysplasia (PMD) is a rare pathology characterized by vascular anomalies, placentomegaly and grapelike vesicles resembling partial molar pregnancy. PMD is often associated with fetal growth restriction or intrauterine fetal demise. We report a case of an early diagnosis of PMD at 10 weeks' gestation, with a regular intrauterine growth and a fetal demise occurring at 31 week's gestation. The placenta showed aneurysmally dilated and tortuous vessels with luminal thrombosis. Even in presence of a regular fetal growth, a fetal demise may always occur, suggesting the option of an early heparin administration to reduce the risk of thrombosis of chorionic vessels. [ABSTRACT FROM AUTHOR]

Aim To assess the use of magnetic resonance imaging ( MRI) for prenatal differentiation between complete hydatidiform mole with a twin live fetus ( CHMTF) and placental mesenchymal dysplasia ( PMD). Methods Three CHMTF cases and three PMD cases, from two institutions over a 6-year period, were retrospectively included in this study. Clinical findings including age, pregnancy history, serum h CG level, ultrasonography findings, complications of the mother, outcome of the fetus, and results of chromosomal study of fetus, amniotic fluid and lesion, if possible, were noted. MRI findings were evaluated by two radiologists with respect to the location of the disease (intra- or extra-fetal sac), the presence of multicystic component, and presence of intra- or extra-lesional hemorrhage. Results In all six cases, the diseases were recognized as multicystic lesions by ultrasonography and MRI. In two of three CHMTF cases, patients continued with the pregnancy, which resulted in spontaneous abortion. In one case of CHMTF, the patient underwent artificial abortion, after which the mole progressed into an invasive mole with lung metastases. All three PMD patients had live births, and two of the three babies had fetal growth restriction. By MRI, CHMTF was located within an extra-fetal sac accompanied by intra- and/or extra-lesional hemorrhage, while PMD was located within the placenta in the fetal sac without hemorrhage. Conclusion MRI could provide important information about the prenatal differential diagnosis of CHMTF and PMD, based on the pathophysiology and characteristics of the diseases. [ABSTRACT FROM AUTHOR]