Misdiagnosis of placental mesenchymal dysplasia as pregnancy with hydatidiform mole: A case report and literature review

RATIONALE

Placental mesenchymal dysplasia (PMD) is a rare placental disease frequently associated with severe maternal and/or fetal complications. Its sonographic appearance is very similar to that of a hydatidiform mole. Hence, PMD is easily misdiagnosed as a hydatidiform mole. In this study, we reported the clinical features of PMD and analyzed its relationship to other severe maternal and/or fetal complications.

PATIENT CONCERNS

A 28-year-old female, gravida 2, para 1, was referred to our maternal and child health hospital at 15 weeks + 2 days due to an ultrasonic diagnosis of partial hydatidiform mole. Analysis of chromosome karyotype + mononucleotide-based gene microarray by amniocentesis at the 19th week of gestation showed that fetal amniocentesis chromosome 46, XN, high-resolution chromosome microarray analysis of Affymetrix CytoScan 750K Array revealed a 210 kb fragment deletion in chromosome 2p16.3 containing NRXN1, an OMIM gene, the deleted fragment was derived from a mother with a normal phenotype. The pregnant woman delivered a healthy baby girl at 36 weeks + 5 days.

DIAGNOSES

Based on the clinical characteristics, imaging, and genetic test findings, the postoperative diagnosis was PMD.

INTERVENTION

Because of "Scar uterus" and "Pregnancy with hydatidiform mole," a 2490 g female infant was delivered by cesarean section at 36 weeks + 5 days of gestation with an Apgar score of 9/9.

OUTCOMES

The maternal human chorionic gonadotropin level decreased to the normal range after 10 days of delivery, and the infant was not found abnormal after 3 months of follow-up.

LESSONS

From our cases and 19 other cases obtained from the PMD literature review are associated with unique clinical, laboratory, and imaging features compared with a hydatidiform mole, such as stained glass sign, normal serum levels of serum human chorionic gonadotropin, elevated alpha-fetoprotein levels and female fetus.

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.

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 with a good outcome: A case report

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.

Optimization, validation, and identification of two reliable antibodies for immunodetection of WNT5A

WNT5A is a secreted, noncanonical WNT signaling protein that has been reported to promote progression of several types of cancer, including oral squamous cell carcinoma. Many WNT5A antibodies are available commercially for immunohistochemistry (IHC) and western blot analysis. Validation of the primary antibodies, however, is often neglected. We characterized antibodies for detecting WNT5A by IHC and western blot analysis. We evaluated one polyclonal and three monoclonal commercially available WNT5A antibodies. After optimization of the IHC assay, all four antibodies showed cytoplasmic WNT5A expression in tissue samples; in contrast, only one antibody detected WNT5A in western blots. A pre-absorption test with recombinant WNT5A showed that AF645 and 3A4 antibodies specifically detected WNT5A in different assays. We suggest that the monoclonal 3A4 antibody is the most appropriate for use with IHC, while the polyclonal AF645 antibody is the best for western blot analysis.