Histopathological diagnosis of partial and complete hydatidiform mole in the first trimester of pregnancy

Clinical features of gestational choriocarcinoma: A retrospective bicentric study

OBJECTIVE

To investigate the clinicopathological features, prognostic factors, treatment, clinical response, and outcome of gestational choriocarcinoma (GCC).

MATERIALS AND METHODS

A retrospective review was made of the clinicopathological and survival data of 13 patients who were diagnosed and treated for GCC in two referral centers in Turkey between 1992 and 2020.

RESULTS

The median age of patients was 36 years (range, 27-54 years), and seven were ≤39 years. The antecedent pregnancy was a term in nine (69.2%) cases, and the risk score was ≥7 in 11 (84.6%). According to the International Federation of Gynecology and Obstetrics 2009 staging, eight cases were in stage I, two in stage III, and three in stage IV. With the exception of one patient, all the others received combination chemotherapy (CT), and two of those were also treated with radiotherapy. Chemoresistance developed in 50% (6/12), and second-line CT was given to four of these. The overall complete response rate was 69.2%. Four patients died of chemoresistance and disease progression, all of them were with antecedent-term pregnancy, had high scores ≥7, and had metastases.

CONCLUSION

GCC is a unique subtype of gestational trophoblastic neoplasia, which differs from others in terms of poor prognosis, a frequent tendency to early metastasis, and resistance to treatment. To be able to achieve the most efficient therapy and prognosis, histopathology-based risk models should be developed.

Intact Chorionic Vesicle in Very Early Products of Conception Specimens: Clinicopathologic Features of 26 Cases That May Mimic Complete Hydatidiform Mole

Among the morphologic mimics of hydatidiform moles, the chorionic vesicle of early first-trimester pregnancy has received scant attention. The chorionic vesicle is the stage of the implanted blastocyst in which the cytotrophoblastic shell is circumferentially lined by primary and secondary villi and envelops the notochord stage embryo, yolk sac, and amniotic sac, ∼5 to 6 weeks since the last menstrual period. Miscarriage specimens at this early gestational age that contain an intact chorionic vesicle may be misinterpreted as a complete hydatidiform mole because of its large size, cistern-like cavity, and circumferentially radiating villi and trophoblast, particularly so when embryonic tissue is absent. We present the clinicopathologic features of 26 products of conception specimens containing a chorionic vesicle, some of which were submitted for consultation as a possible complete mole. The median gestational age was 6 weeks. The majority were free-floating in the specimen, unattached to endometrium. The median diameter was 6.3 mm and ranged up to 11.3 mm. The embryo was absent in 81% of cases, leaving an empty cavity resembling the cistern of a complete mole in all but 2 cases. Most cases exhibited circumferential villi and variable degrees of proliferating polarized villous trophoblast and extravillous trophoblast but trophoblast atypia was absent. Villous stromal karyorrhexis and blue-gray myxoid extracellular stromal matrix were observed in the majority of cases. A minority exhibited focal abnormal villous morphology concerning for early molar pregnancy, including irregular projections (27%), invaginations (12%), or bulbous shapes (4%) of the villous contours and trophoblast pseudoinclusions (15%). In contrast, orderly hierarchical branching of the secondary villi occurred in 31%. p57 immunoexpression was intact in all 25 cases tested. Short tandem repeat genotype testing confirmed a biparental diploid genotype in both of 2 cases tested. Although uncommonly observed in early first-trimester products of conception specimens, the normal chorionic vesicle merits awareness as a potential diagnostic pitfall. While some morphologic features resemble those of a well-developed complete mole, at this early gestational age such features are not expected in a very early complete mole. Attention to the reported gestational age, if available, and presence of embryonic tissues will mitigate against misclassification as complete mole. As with the workup of any potential gestational trophoblastic disease, partnering the clinical and morphologic evaluation with molecular evaluation (intact p57 immunoexpression and lack of any of the characteristic molar genotypes) offers the most precise classification.

Gestational trophoblastic disease: an update

Gestational trophoblastic diseases (GTD) encompass a spectrum of rare pre-malignant and malignant entities originating from trophoblastic tissue. This updated review will highlight important radiological features, pathology and classification, and provide insight into the clinical management of these uncommon disorders. There is a wide geographic variation with the incidence of hydatidiform mole varying between 0.57 and 2 per 1000 pregnancies. The use of ultrasound (US) in the management of early pregnancy symptoms and complications has positively impacted the earlier detection of these diseases and resulted in diminished morbidity. Additional imaging modalities are reserved for problem solving or assessment of pulmonary manifestations of molar pregnancy. Having an awareness of their pleomorphic sonographic presentation and additional pathology that can mimic GTD is critical to avoiding pitfalls. Histologic and molecular analysis further aids in differential diagnosis. Gestational trophoblastic neoplasia (GTN) is inclusive of all malignant GTDs, and arises after 20% of molar pregnancies but can also be seen with non-molar gestations. Biochemical monitoring with human chorionic gonadotrophin is imperative for ongoing monitoring and surveillance and allows early detection of this entity. Doppler US is used for confirmation of diagnosis with magnetic resonance imaging (MRI) reserved for problem solving or assessment of myometrial invasion. This is of heightened relevance in patients undergoing surgical management. Cross sectional imaging is reserved for patients in the setting of GTN for the purposes of staging, prognostication and in the setting of recurrent disease. This may require a combination of computed tomography, MRI and positron emission tomography. Doppler US can provide insight into chemotherapeutic response/predict resistance in patients with GTN. As our understanding of these disorders evolves, there has been maturation in management options with a shift from traditional chemotherapy to innovative immunotherapy, particularly in the setting of resistant or high-risk disease.

Gestational Trophoblastic Disease: Contemporary Diagnostic Approach

Pathologic diagnosis of gestational trophoblastic disease (GTD)-hydatidiform moles and gestational trophoblastic neoplasms-underwent a major shift in the past decade from morphology-based recognition to precise molecular genetic classification of entities, which also allows for prognostic stratification of molar gestations. This article highlights these recent advances and their integration into the routine pathology practice. The traditional gross and histomorphologic features of each entity are also reviewed with special focus on differential diagnoses and their clinical implications.

Androgenetic/Biparental Mosaic/Chimeric Conceptions With a Molar Component: A Diagnostic and Clinical Challenge

Hydatidiform moles (HM) are gestational trophoblastic diseases which arise due to an imbalance in genetic material and which are morphologically characterized by enlarged and irregular chorionic villi and trophoblastic hyperplasia, among other features. The morphologic differential diagnosis for HM encompasses a number of entities including androgenetic/biparental mosaic/chimeric (ABMC) conceptions, an interesting duo of lesions with a nonmolar form (placental mesenchymal dysplasia) and a molar form (typically with a complete HM component). ABMC conceptions contain a mixture of 2 cell populations (1 androgenetic and 1 biparental) and arise as a result of mosaicism (mitotic error in a zygote) or chimerism (fusion of 2 zygotes). Because of their unique molecular underpinnings, these rare lesions show a number of findings including the presence of multiple villous populations, discordant p57 immunostaining, and mixed genotypes. ABMC conceptions are important to accurately diagnose as the molar form in particular carries a risk for persistent gestational trophoblastic diseases and thus requires appropriate treatment and follow-up. In this report, we provide detailed characterizations of 2 such cases of ABMC conceptions with a molar component. Both patients (ages 34 and 31) were in the first trimester of pregnancy and had ultrasound findings concerning for HM. Increased comprehension of the pathogenesis and morphology of ABMC conceptions, combined with ancillary techniques including p57 immunohistochemistry, fluorescence in situ hybridization, and molar genotyping, has allowed us to accurately and efficiently identify these lesions. However, a number of pitfalls exist which may lead to misdiagnosis.

Genotyping diagnosis of gestational trophoblastic disease: frontiers in precision medicine

Investigations in recent decades have exploited tissue DNA genotyping as a powerful ancillary tool for the precision diagnosis and subclassification of gestational trophoblastic disease. As lesions of gestational origin, the inherited paternal genome, with or without copy number alterations, is the fundamental molecular basis for the diagnostic applications of DNA genotyping. Genotyping is now considered the gold standard in the confirmation and subtyping of sporadic hydatidiform moles. Although a precise diagnosis of partial mole requires DNA genotyping, prognostic stratification according to distinct genetic zygosity in complete moles has recently gained significant clinical relevance for patient care. Beyond hydatidiform moles, DNA genotyping has fundamental applications in the diagnosis or prognostic assessment of gestational trophoblastic tumors, in particular gestational choriocarcinoma. DNA genotyping provides a decisive tool in the separation of gestational trophoblastic neoplasia from non-gestational counterparts/mimics of either germ cell or somatic origin. The FIGO/WHO prognostic scoring scheme requires ascertaining the precise index gestational event and the time interval between the tumor and index gestation, where DNA genotyping can provide highly relevant information. With rapid acquisition of molecular diagnostic capabilities in the clinical practice, DNA genotyping has become closely integrated into the routine diagnostic workup of various forms of gestational trophoblastic disease.

Refined diagnosis of hydatidiform moles with p57 immunohistochemistry and molecular genotyping: updated analysis of a prospective series of 2217 cases

Immunohistochemical analysis of p57 expression and molecular genotyping accurately subclassify molar specimens into complete hydatidiform mole (CHM) and partial hydatidiform mole (PHM) and distinguish these from nonmolar specimens. Characteristics of a prospective series of potentially molar specimens analyzed in a large gynecologic pathology practice are summarized. Of 2217 cases (2160 uterine, 57 ectopic), 2080 (94%) were successfully classified: 571 CHMs (570 uterine, 1 ectopic), 498 PHMs (497 uterine, 1 ectopic), 900 nonmolar (including 147 trisomies, 19 digynic triploids, and 4 donor egg conceptions), and 56 androgenetic/biparental mosaics; 137 were complex or unsatisfactory and not definitively classified. CHMs dominated in patients aged < 21 and >45 years and were the only kind of molar conception found in the latter group. Of 564 successfully immunostained CHMs, 563 (99.8%) were p57-negative (1 p57-positive [retained maternal chromosome 11] androgenetic by genotyping). Of 153 genotyped CHMs, 148 (96.7%) were androgenetic (85% monospermic) and 5 were biparental, the latter likely familial biparental hydatidiform moles. Of 486 successfully immunostained PHMs, 481 (99%) were p57-positive (3 p57-negative [loss of maternal chromosome 11], 2 unknown mechanism). Of 497 genotyped PHMs, 484 (97%) were diandric triploid (99% dispermic) and 13 were triandric tetraploid (all at least dispermic). Of 56 androgenetic/biparental mosaics, 37 had a p57-negative complete molar component (16 confirmed as androgenetic by genotyping). p57 expression is highly correlated with genotyping, serving as a reliable marker for CHMs, and identifies molar components and androgenetic cell lines in mosaic conceptions. Correlation of morphology, p57 expression, genotyping data, and history are required to recognize familial biparental hydatidiform moles and donor egg conceptions, as the former can be misclassified as nonmolar and the latter can be misclassified as dispermic CHM on the basis of isolated genotyping results.

"While there is p57, there is hope." The past and the present of diagnosis in first trimester abortions: Diagnostic dilemmas and algorithmic approaches. A review

Distinction of hydatidiform moles (HM) from non-molar (NM) specimens and subclassification of HM as complete hydatidiform mole (CHM) versus partial hydatidiform mole (PHM) are important for clinical practice and investigational studies. The issue of diagnostic reproducibility is still unsolved, the lack of diagnostic accuracy based on morphology is substantial with an important interobserver variability, even between experienced gynecologic pathologists. Many ancillary techniques have been investigated in the last years to refine HM diagnosis. p57 (a paternally imprinted, maternally expressed gene) immunohistochemistry, based on the unique genetics of CHM (purely androgenetic), PHM (diandric triploid), and NM specimens (biparental, with allelic balance) can identify CHMs, which lack p57 expression because of a lack of maternal DNA. However, although its role in HM diagnosis is pivotal, it does not allow the distinction of PHM from NM specimens, both of which express p57 due to the presence of maternal DNA. Molecular genotyping, which compares villous and decidual DNA patterns to determine the parental source and ratios of polymorphic alleles, distinguishes purely androgenetic CHM from diandric triploid PHM, and both of these from NM specimens. Beyond the claim of establishing a "diagnostic truth", exceptions and peculiar genetic scenarios in the origin of rare CHM and PHM should be kept in mind when approaching any ancillary technique. An algorithmic approach, even in settings with limited resources, can help the pathologists in the diagnostic dilemma of diagnosis of first trimester abortions.

Prevalence of Partial Hydatidiform Mole in Products of Conception From Gestations With Fetal Triploidy Merits Reflex Genotype Testing Independent of the Morphologic Appearance of the Chorionic Villi

Diagnosis of first-trimester partial mole is challenging as the key morphologic features may not be well-developed and may overlap with those of a nonmolar gestation harboring a cytogenetic disorder or degenerative changes. Genotype testing has emerged as the reference tool to distinguish partial mole (diandric triploid genotype) from its nonmolar mimics. However, observer variation in defining the minimum threshold of how much morphologic alteration is required to trigger genotype testing may result in a subset of partial moles that go undetected. We hypothesized that the results of fetal aneuploidy testing performed for prenatal screening or evaluation of miscarriage may assist with triggering molecular testing in the evaluation of products of conception, specifically if fetal triploidy is detected. Gestations with fetal triploidy are either a partial mole (diandric triploidy) or are nonmolar (digynic triploidy). The aims of this study were to define the prevalence of partial mole in 20 products of conception specimens with known fetal triploidy by performing genotype testing and then to determine how well established morphologic criteria for partial mole correlate with the genotype results in this setting. Genotype testing demonstrated that 65% (13/20) were a partial mole and the remainder were nonmolar digynic triploid gestations. Most partial moles were under 9 weeks gestational age and, as expected, lacked classic well-developed morphologic features. Nearly a third (4/13) of the partial moles were originally interpreted as normal or nonmolar gestations with minimal abnormalities that did not merit molecular testing to exclude a partial mole. Even with the retrospective systematic morphologic review, only 23% (3/13) exhibited the combination of chorionic villous enlargement of ≥2.5 mm and cisterns, which has been previously established as the morphologic criteria with the highest predictive value for a molecularly defined partial mole. The other 77% exhibited focal, limited, variable degrees and extent of villous morphologic alterations. We conclude that, given the high prevalence of partial mole among products of conception with known fetal triploidy and the low prevalence of diagnostic morphologic findings in such specimens, reflex genotype testing should be performed in all such cases, regardless of whether or not the morphologic features are suspicious for a partial mole. This reflex testing strategy mitigates against the subjectivity of determining whether subtle villous abnormalities are significant enough to merit pursuing genotype testing. The success of this strategy depends on the clinician documenting the fetal triploidy result at the time of submitting the products of conception specimen and therefore clinician education is needed. Finally, it remains to be determined whether the risk for postmolar gestational trophoblastic disease is the same in diandric triploid gestations that exhibit classic morphologic features as in those that exhibit minimal or negligible villous morphologic abnormalities.

A molar pregnancy in an embryo donor cow

A 6-year-old Hereford embryo donor cow was referred to Auburn University College of Veterinary Medicine for a mass in the tip of her left uterine horn. The cow had recently undergone an embryo collection which yielded unfertilized, degenerated ova. Transrectal palpation and ultrasound revealed a multi-locular mass enveloped by two separate compartments that resembled an amniotic and allantoic cavity within the uterus. Tissue was collected via a uterine flush and submitted for histopathology. The tissue was determined to be placenta, confirming the diagnosis of a molar pregnancy. Following treatment, the cow was able to produce numerous viable embryos. Molar pregnancies are rare and characterized by abnormal growth of trophoblastic cells leading to formation of intrauterine cystic masses. It is important to routinely perform an ultrasonographic examination of the cow's reproductive tract approximately 30 days following non-surgical in vivo embryo collections to detect and treat unwanted conditions such as pregnancy and cystic conditions.

Pre-operative classification of molar pregnancy: How good is ultrasound?

BACKGROUND

Histopathology is the reference standard for diagnosing hydatidiform molar pregnancy (HMP).

AIM

To assess the performance of pre-operative transvaginal ultrasound (TVS) to predict HMP.

MATERIALS AND METHODS

A retrospective diagnostic accuracy study was performed on women who had both TVS and histopathological examination of uterine curettings between January 2011-February 2017. TVS diagnosis of partial MP (PMP) included assessment of fetal parts and/or empty gestational sac with small cystic spaces adjacent to gestational sac. TVS diagnosis of complete MP (CMP) included assessment of complex, echogenic intra-uterine mass(es) containing multiple small cystic areas. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive and negative likelihood ratios (PLR/NLR) for TVS were reported. Reference standard was histology.

RESULTS

There were 4917 consecutive women who underwent TVS; 1636 underwent surgical curettage for miscarriage. Forty out of 4917 (0.6%) had HMP histologically; 25/40 (62.5%) had suspected HMP and 15/40 (37.5%) did not; 24/40 (60.0%) had CMP of which 19/24 (79.1%) were suspected on TVS and 5/24 (20.8%) were not; 16/40 (40.0%) had PMP of which 6/16 (37.5%) were suspected on TVS and 10/16 (62.6%) were not. The sensitivity, specificity, PPV, NPV, PLR and NLR of pre-operative TVS to predict HMP were: 60.0, 99.1, 63.2, 99.0% 68.4, 0.4; for CMP: 79.2, 99.8, 86.3, 99.6%, 421.7, 0.2; for PMP: 37.5, 99.3, 35.3, 99.4%, 54.3, 0.6.

CONCLUSION

Histology remains the gold standard for diagnosing HMP. TVS is an acceptable diagnostic tool for HMP. When there are no ultrasound features of HMP, almost all these women will not have an underlying HMP.

Hydatidiform Moles: Ancillary Techniques to Refine Diagnosis

Context.—

Distinction of hydatidiform moles from nonmolar specimens and subclassification of hydatidiform moles as complete hydatidiform mole versus partial hydatidiform mole are important for clinical practice and investigational studies. Risk of persistent gestational trophoblastic disease and clinical management differ for these entities. Diagnosis based on morphology is subject to interobserver variability and remains problematic, even for experienced gynecologic pathologists.

Objectives.—

To explain how ancillary techniques target the unique genetic features of hydatidiform moles to establish diagnostic truth, highlight the issue of diagnostic reproducibility and importance of diagnostic accuracy, and illustrate use of p57 immunohistochemistry and polymerase chain reaction–based DNA genotyping for diagnosis.

Data Sources.—

Sources are the author's 10-year experience using ancillary techniques for the evaluation of potentially molar specimens in a large gynecologic pathology practice and the literature.

Conclusions.—

The unique genetics of complete hydatidiform moles (purely androgenetic), partial hydatidiform moles (diandric triploid), and nonmolar specimens (biparental, with allelic balance) allow for certain techniques, including immunohistochemical analysis of p57 expression (a paternally imprinted, maternally expressed gene) and genotyping, to refine diagnoses of hydatidiform moles. Although p57 immunostaining alone can identify complete hydatidiform moles, which lack p57 expression because of a lack of maternal DNA, this analysis does not distinguish partial hydatidiform moles from nonmolar specimens because both express p57 because of the presence of maternal DNA. Genotyping, which compares villous and decidual DNA patterns to determine the parental source and ratios of polymorphic alleles, distinguishes purely androgenetic complete hydatidiform moles from diandric triploid partial hydatidiform moles, and both of these from biparental nonmolar specimens. An algorithmic approach to diagnosis using these techniques is advocated.

Lectin histochemical analysis of uterine natural killer cells in normal, hydatidiform molar and invasive molar pregnancy

Uterine natural killer (uNK) cells have been hypothesized to serve a role in controlling trophoblast invasion and proliferation. The aim of the present study was to identify the distribution and number of uNK cells in normal pregnancy (NP), partial mole (PM), complete mole (CM) and invasive mole (IM). uNK cells were detected using dolichos biflorus agglutinin lectin immunohistochemistry in decidual and villous tissues from early NP (n=15), late NP (n=15), PM (n=22), CM (n=20) and IM (n=10). A scaled eye piece was used for cell counting to obtain semi-quantitative results. It was revealed that uNK cells were mainly located in the uterine deciduas of early NP. As pregnancy progressed, the number of decidual uNK cells significantly decreased. Decidual uNK cells of PM, CM and IM were located near blood vessel endothelial cells. No significant differences were detected with respect to the numbers of decidual uNK between early NP and PM. However, the number of decidual uNK cells was significantly reduced in CM and IM compared with early NP. The populations of decidual uNK cells were not significantly different between CM and IM. No uNK cells were detected in the villi of PM, CM or IM. The decrease of decidual uNK cells in late NP, CP and IM, compared with early NP, suggested that uNK cells served an important role in controlling trophoblast invasion and proliferation.

Comparison of 2 Human Chorionic Gonadotropin Immunoassays Commercially Available for Monitoring Patients With Gestational Trophoblastic Disease

OBJECTIVE

The aim of this study was to compare serum human chorionic gonadotropin (hCG) levels in patients with gestational trophoblastic disease (GTD) using 2 commercially available hCG immunoassays.

METHODS

Serum samples were obtained from patients with GTD attending the Botucatu Medical School Trophoblastic Diseases Center of São Paulo State University (UNESP), from November 2014 to October 2015. Serum hCG levels were measured with both Architect i2000SR and Immulite 2000 XPi chemiluminescence assays. Serum hCG levels were compared against the null hypothesis. Agreement in clinical management decisions based on the hCG results was determined by comparing baseline hCG measurements and the hCG curves obtained with both assays.

RESULTS

Seventy-three patients with GTD were included in the analysis. Of these, 45 had hydatidiform mole and spontaneous remission, whereas 28 had gestational trophoblastic neoplasia (GTN). There was a perfect (zero difference) agreement in mean hCG levels between Immulite 2000 XPi and Architect i2000 when hCG is less than 100 mIU/mL. For hCG values greater than 100 mIU/mL, there was a significant difference between assays (P < 0.05), with levels measured via Architect i2000SR being higher than those measured by Immulite 2000 XPi in patients with hydatidiform mole/spontaneous remission (R = 90%, P < 0.01) and GTN (R = 98%, P < 0.01). Baseline clinical management decisions showed agreement in 100% (73/37) of cases (κ = 1.0, P < 0.001), whereas decisions based on hCG curve agreed in 98% (71/72) of cases (κ = 0.93, P < 0.001).

CONCLUSIONS

Immulite 2000 XPi is the most frequently recommended assay for diagnosing and monitoring patients with GTD. However, our results suggest that because Immulite 2000 XPi and Architect i2000 show very similar performance in measuring hCG levels and in determining clinical management, Architect may be used as an alternative.

Insights into dovetailing GTD and Cancers

Gestational trophoblastic diseases (GTD) encompass a group of placental tumors which mostly arise due to certain fertilization defects, resulting in the over-proliferation of trophoblasts. The major characteristic of this diseased state is that β-hCG rises up manifold than that is observed during pregnancy. The incidence of GTD when analyzed on a global scale, figures out that there is a greater risk in South-East Asia, the reason of which remains unclear. An insight into any possible correlation of GTD incidence with cancers, other than choriocarcinoma, is being attempted here. Also, we review the recent developments in research on the molecular etiopathology of GTD. This review would render a wider eye towards a new paradigm of thoughts to connect GTD and breast cancer, which has not been into the picture till date.

Single nucleotide polymorphism-based microarray analysis for the diagnosis of hydatidiform moles

In clinical diagnostics, single nucleotide polymorphism (SNP)-based microarray analysis enables the detection of copy number variations (CNVs), as well as copy number neutral regions, that are absent of heterozygosity throughout the genome. The aim of the present study was to evaluate the effectiveness and sensitivity of SNP‑based microarray analysis in the diagnosis of hydatidiform mole (HM). By using whole‑genome SNP microarray analysis, villous genotypes were detected, and the ploidy of villous tissue was determined to identify HMs. A total of 66 villous tissues and two twin tissues were assessed in the present study. Among these samples, 11 were triploid, one was tetraploid, 23 were abnormal aneuploidy, three were complete genome homozygosity, and the remaining ones were normal ploidy. The most noteworthy finding of the present study was the identification of six partial HMs and three complete HMs from those samples that were not identified as being HMs on the basis of the initial diagnosis of experienced obstetricians. This study has demonstrated that the application of an SNP‑based microarray analysis was able to increase the sensitivity of diagnosis for HMs with partial and complete HMs, which makes the identification of these diseases at an early gestational age possible.

Abnormal villous morphology mimicking a hydatidiform mole associated with paternal trisomy of chromosomes 3,7,8 and unipaternal disomy of chromosome 11

Background

Pregnancies affected by non-molar chromosomal abnormality may sometimes demonstrate abnormal chorionic villous morphology that is similar to partial hydatidiform mole. Determination of the underlying aetiology may be difficult in such cases.

Case Presentation

This report describes a case referred to the regional trophoblastic disease unit as a possible hydatidiform mole that demonstrated both villous dysmorphology and abnormal p57^KIP2 expression. Molecular genotyping revealed that while most chromosomes in the villous tissue were diploid and biparental, chromosomes 3, 7 and 8 were trisomic with an additional paternally derived chromosome. In contrast chromosome 11 showed uniparental disomy of paternal origin a situation more usually associated with complete hydatidiform moles. This unusual case highlights that exceptions may occur to the general rules of both histological morphology and immunoprofile, and that these can be resolved by detailed molecular genetic investigations.

Conclusion

The findings confirm that trisomic pregnancies may demonstrate morphological villous features similar to hydatidiform mole, and that loss of p57^KIP2 expression occurs due to an absence of maternally transcribed genes on chromosome 11 and can therefore be independent of androgenetic complete hydatidiform mole.

Flow Cytometric DNA Analysis and Histopathologic Re-Evaluation of Paraffin Embedded Samples from Hydatidiform Moles and Hydropic Abortions

Background

Distinction of hydatidiform moles (HMs) from non-molar abortions and sub-classification of HMs are important for clinical practice; yet, diagnosis based solely on morphology is affected by interobserver variability. The objective of this study was to determine the role of DNA flow cytometry in distinguishing molar from non-molar pregnancies.

Materials and Methods

This retrospective study was conducted at the Department of Pathology, Women’s Hospital, Tehran University of Medical Sciences, Tehran, Iran, between 2006 and 2010. DNA ploidy analysis and histopathologic re-evaluation were performed on paraffin-embedded tissue from 36 (17 complete and 19 partial) molar and 24 hydropic abortus (HA) cases which were previously diagnosed based on histomorphologic study.

Results

Of the 17 cases initially diagnosed as complete HM (CHM), 9 were diploid, 2 were triploid, 5 were tetraploid and 1 was aneuploid. Of the 19 initial partial HMs (PHMs), 2, 8, 1 and 8 cases were diploid, triploid, tetraploid and aneuploid, respectively. In the initial HA category (n=24), 14 diploid, 1 triploid, 5 tetraploid, and 4 aneuploid cases existed. Following flow cytometry and histopathologic reevaluation, 1 case with previous diagnosis of HA was reclassified as PHM, 2 initial PHMs were reclassified as CHM and 2 initial CHMs were categorized as PHM.

Conclusion

The results show that correct diagnosis of PMH is the main challenge in histological diagnosis of gestational trophoblastic disease (GTD). DNA flow cytometric analysis could be an informative supplement to the histological interpretation of molar and hydropic placentas.

Gestational Trophoblastic Disorders: An Update in 2015

Gestational trophoblastic diseases (GTD) are a group of pregnancy-related disorders representing rare human tumours. They encompass premalignant disorders including complete (CHM), partial hydatidiform mole (PHM), exaggerated placental site (EPS), and placental-site nodule (PSN) as well as malignant disorders (also known as "gestational trophoblastic neoplasia [GTN]") including invasive mole, choriocarcinoma (CC), placenta-site trophoblastic tumour (PSTT), and epitheloid trophoblastic tumours (ETT) (Fig. 1). Originally, GTD develop from abnormal proliferation of trophoblastic tissue and form botryoid arranged vesicles. Premalignant moles are usually treated by suction curettage while persistent and recurrent moles and malignant forms require systemic therapy with methotrexate or combination chemotherapy consisting of etoposide, actimomycin D, methotrexate, vincristine, and cyclophosphamide (EMA-CO). β-human chorion gonadotropin (β-hCG) plays a crucial role in diagnosis and monitoring therapeutic effects. Since the definitive diagnosis cannot be obtained by histology in most cases, persistent or recurrent disease is diagnosed by elevated or persistent serum levels of β-hCG. While curing rates are described to be as high as 98 %, GTD may initially present, recur, or end up as a metastasising systemic disease. This underlines the importance of a regular and consistent follow-up after treatment.

Hormonal contraceptive use before hCG remission does not increase the risk of gestational trophoblastic neoplasia following complete hydatidiform mole: a historical database review

OBJECTIVE

To re-evaluate the safety of hormonal contraceptives (HC) after uterine evacuation of complete hydatidiform mole (CHM).

DESIGN

Historical database review.

SETTING

Charing Cross Hospital Gestational Trophoblastic Disease Centre, London, United Kingdom.

POPULATION

Two thousand four hundred and twenty-three women with CHM of whom 154 commenced HC while their human chorionic gonadotropin (hCG) was still elevated, followed between 2003 and 2012.

METHODS

We compared time to hCG remission between HC users and nonusers. The relationship between HC use and gestational trophoblastic neoplasia (GTN) development was assessed. The relationship between HC use and a high International Federation of Gynecology and Obstetrics (FIGO) risk score was determined.

MAIN OUTCOME MEASURES

Time to hCG remission, risk of developing postmolar GTN and proportion of women with high FIGO risk score.

RESULTS

No relationship was observed between HC use with mean time to hCG remission (HC users versus non-users: 12 weeks in both, P = 0.19), GTN development (HC users versus non-users: 20.1 and 16.7%, P = 0.26) or high-risk FIGO score (HC users versus nonusers: 0% and 8%, P = 0.15). Moreover, no association between HC and GTN development was found, even when an age-adjusted model was used (OR = 1.37, 95% CI 0.91-2.08, P = 0.13).

CONCLUSIONS

The use of current HC is not associated with development of postmolar GTN or delayed time to hCG remission. Therefore, HC can be safely used to prevent a new conception following CHM regardless of hCG level.

TWEETABLE ABSTRACT

Non-concurrent cohort study to re-evaluate the safety of low dose HCs after uterine evacuation of CHM.

Defective pericyte recruitment of villous stromal vessels as the possible etiologic cause of hydropic change in complete hydatidiform mole

The pathogenetic mechanism underlying the hydropic change in complete hydatidiform moles (CHMs) is poorly understood. A growing body of data suggests that pericytes play a role in vascular maturation. Since maturation of villous stromal vessels in CHMs is markedly impaired at early stages, we postulated that a defect in pericytes around stromal vessels in chorionic villi might cause vascular immaturity and subsequent hydropic change. To investigate this, we examined several markers of pericytes, namely, α-smooth muscle actin (α-SMA), platelet-derived growth factor receptor-β (PDGFR-β), and desmin, in 61 normally developing placentas and 41 CHMs with gestational ages of 4-12 weeks. The ultrastructure of villous stromal vessels was also examined. Mature blood vessels from normal placentas show patent vascular lumens and formed hematopoietic components in the villous stroma. α-SMA and PDGFR-β expression in the villous stroma gradually increased and extended from the chorionic plate to peripheral villous branches. The labeled cells formed a reticular network in the villous stroma and, after week 7, encircled villous stromal vessels. In comparison, α-SMA and PDGFR-β expression in the villous stroma and stromal vessels of CHMs was significantly lower (p<0.05). Ultrastructurally, endothelial cells in villous stromal vessels in normal placentas were consistently attached by pericytes after week 7 when the vessels formed distinct lumen, whereas the villous stromal vessels in CHMs consisted of linear chains of endothelial cells, often disclosing primitive clefts without hematopoietic cells inside, and neither pericytes nor basal lamina surrounded the endothelial cells at any gestational age studied. This suggests that pericytes recruitment around villous stromal vessels is defective in CHMs and links to the persistent vascular immaturity of the villous stroma in CHMs, which in turns leads to hydropic villi.

Ovarian and adrenal androgens and their link to high human chorionic gonadotropin levels: a prospective controlled study

Background. Although the association between human chorionic gonadotropin (hCG) and hyperandrogenism was identified more than 40 years ago, relevant questions remain unanswered. Design and Methods. We conducted a prospective, longitudinal, and controlled study in 23 women with a diagnosis of a complete hydatidiform mole (HM). Results. All participants completed the study. Before HM evacuation mean hCG was markedly higher in the cases than in the control group (P ≤ 0.001). Free testosterone (T) and dehydroepiandrosterone sulfate (DHEA-S) were found to be higher in the cases (2.78 ± 1.24 pg/mL and 231.50 ± 127.20 μ/dL) when compared to the control group (1.50 ± 0.75 pg/mL and 133.59 ± 60.69 μ/dL) (P = 0.0001 and 0.001), respectively. There was a strong correlation between hCG and free T/total T/DHEA-S concentrations (r = 0.78; P ≤ 0.001, r = 0.74;  P ≤ 0.001, and r = 0.71;  P ≤ 0.001), respectively. In the cases group 48 hours after HM evacuation, hCG levels were found to be significantly lower when compared to initial levels (P = 0.001) and free T and DHEA-S declined significantly (P = 0.0002 and 0.009). Conclusion. Before uterus evacuation, hCG, free T, and DHEA-S levels were significantly higher when compared with controls finding a strong correlation between hCG and free T/DHEA-S levels. Forty-eight hours after HM treatment hCG levels declined and the difference was lost. A novel finding of our study is that in cases, besides free T, DHEA-S was also found to be significantly higher and both the ovaries and adrenal glands appear to be the sites of this androgen overproduction.

Diagnostic reproducibility of hydatidiform moles: ancillary techniques (p57 immunohistochemistry and molecular genotyping) improve morphologic diagnosis for both recently trained and experienced gynecologic pathologists

Distinction of hydatidiform moles from nonmolar specimens (NMs) and subclassification of hydatidiform moles as complete hydatidiform mole (CHM) and partial hydatidiform mole (PHM) are important for clinical practice and investigational studies; however, diagnosis based solely on morphology is affected by interobserver variability. Molecular genotyping can distinguish these entities by discerning androgenetic diploidy, diandric triploidy, and biparental diploidy to diagnose CHMs, PHMs, and NMs, respectively. Eighty genotyped cases (27 CHMs, 27 PHMs, 26 NMs) were selected from a series of 200 potentially molar specimens previously diagnosed using p57 immunohistochemistry and genotyping. Cases were classified by 6 pathologists (3 faculty level gynecologic pathologists and 3 fellows) on the basis of morphology, masked to p57 immunostaining and genotyping results, into 1 of 3 categories (CHM, PHM, or NM) during 2 diagnostic rounds; a third round incorporating p57 immunostaining results was also conducted. Consensus diagnoses (those rendered by 2 of 3 pathologists in each group) were also determined. Performance of experienced gynecologic pathologists versus fellow pathologists was compared, using genotyping results as the gold standard. Correct classification of CHMs ranged from 59% to 100%; there were no statistically significant differences in performance of faculty versus fellows in any round (P-values of 0.13, 0.67, and 0.54 for rounds 1 to 3, respectively). Correct classification of PHMs ranged from 26% to 93%, with statistically significantly better performance of faculty versus fellows in each round (P-values of 0.04, <0.01, and <0.01 for rounds 1 to 3, respectively). Correct classification of NMs ranged from 31% to 92%, with statistically significantly better performance of faculty only in round 2 (P-values of 1.0, <0.01, and 0.61 for rounds 1 to 3, respectively). Correct classification of all cases combined ranged from 51% to 75% by morphology and 70% to 80% with p57, with statistically significantly better performance of faculty only in round 2 (P-values of 0.69, <0.01, and 0.15 for rounds 1 to 3, respectively). p57 immunostaining significantly improved recognition of CHMs (P<0.01) and had high reproducibility (κ=0.93 to 0.96) but had no impact on distinction of PHMs and NMs. Genotyping provides a definitive diagnosis for the ∼25% to 50% of cases that are misclassified by morphology, especially those that are also unresolved by p57 immunostaining.

Mutations in NLRP7 and KHDC3L confer a complete hydatidiform mole phenotype on digynic triploid conceptions

Digynic triploidy is classically associated with a severely growth restricted fetus and a small nonmolar placenta. However, in genotyping hydatidiform moles as part of clinical practice, we identified two digynic triploid conceptions presenting with histopathological features of classical complete hydatidiform mole (CHM). Both cases occurred in women with a history of previous molar pregnancies and no normal pregnancies. Pathological review and genotyping of other molar pregnancies in these cases showed them to be typical CHM with negative p57(KIP2) immunostaining of the cytotrophoblast cells and villous stroma and to be diploid but biparental, confirming a diagnosis of familial recurrent hydatidiform mole (FRHM). Mutation screening of NLRP7 had identified a homozygous duplication, leading to a truncated protein, in case 1 whereas mutation screening of KHDC3L (C6orf221) in case 2 showed both the proband and her sister to be compound heterozygotes for mutations in KHDC3L. The observation of a single digynic, triploid conception presenting as a CHM in women with FRHM, where other pregnancies are diploid and biparental, supports the hypothesis that the role of both NLRP7 and KHDC3L in pregnancy is in setting and/or maintaining the maternal imprint. Clinically, a diagnosis of FRHM should be considered in women with genetically unusual conceptions that are phenotypically CHM.

Diagnosis of hydatidiform moles by polymorphic deletion probe fluorescence in situ hybridization

Because products of conception often contain maternal and villous tissues, the determination of maternal and villous genotypes based on genetic polymorphisms can help discern maternal and paternal chromosomal contribution and aid in the diagnosis of hydatidiform moles. Polymorphic deletion probe (PDP) fluorescence in situ hybridization (FISH) probes based on copy number variants are highly polymorphic and allow in situ determination of genetic identity. By using three informative PDPs on chromosomes 2p, 4q, and 8p, we compared maternal with villous genotypes and determined the ploidy of villous tissue. PDP FISH was performed on 13 complete moles, 13 partial moles, 13 nonmolar abortions, and an equivocal hydropic abortion. PDP FISH permitted definitive diagnosis of complete moles in five of 13 cases for which maternal and villous genotypes were mutually exclusive. A complete mole was highly suspected when all three PDP loci showed homozygous villous genotypes. The diagnosis of a complete mole by PDP FISH yielded a theoretical test sensitivity of 87.5%, specificity of 91.8%, an observed test sensitivity of 100%, and specificity of 92.3%. Triploidy was observed in all partial moles, in which diandric triploidy was confirmed in six cases. In the equivocal hydropic abortion, PDP FISH combined with p57 immunofluorescence revealed placental androgenetic/biparental mosaicism. PDP FISH can be used in clinical practice and research studies to subclassify hydatidiform moles and evaluate unusual products of conception.

Partial molar pregnancy with a chromosomically and phenotypically normal embryo: presentation of an extremely rare case and review of literature

We present an extremely rare case of partial molar pregnancy with a chromosomically and phenotypically normal embryo and review of the literature. A 31-year-old nulliparous was referred to us at 30 weeks of gestation due to absence of fetal movements and subsequent ultrasound examination revealed intrauterine demise. Prenatal amniocentesis due to raised maternal serum α-fetoprotein had shown a karyotypically normal female embryo and second trimester ultrasound demonstrated no anatomic abnormalities. Upon induction of labor with misoprostol, a phenotypically normal embryo was delivered and the placenta showed intermixed areas of marked hydatidiform villous change and normal parenchyma. Pathologic examination of the placenta confirmed the molar change of placenta. Two are the main theories discussed herein that explain the placental molar changes in singleton pregnancies: confined placental mosaicism (one case reported to date) and placental mesenchymal dysplasia (70 cases reported). Differential diagnosis is based on histopathologic features and genetic analysis of placenta.

Gestational trophoblastic disease I: epidemiology, pathology, clinical presentation and diagnosis of gestational trophoblastic disease, and management of hydatidiform mole

Gestational trophoblastic disease includes hydatidiform mole (complete and partial) and gestational trophoblastic neoplasia (invasive mole, choriocarcinoma, placental site trophoblastic tumor, and epithelioid trophoblastic tumor). The epidemiology, pathology, clinical presentation, and diagnosis of each of these trophoblastic disease variants are discussed. Particular emphasis is given to management of hydatidiform mole, including evacuation, twin mole/normal fetus pregnancy, prophylactic chemotherapy, and follow-up.

Gestational trophoblastic disease

Gestational trophoblastic disease encompasses a range of pregnancy-related disorders, consisting of the premalignant disorders of complete and partial hydatidiform mole, and the malignant disorders of invasive mole, choriocarcinoma, and the rare placental-site trophoblastic tumour. These malignant forms are termed gestational trophoblastic tumours or neoplasia. Improvements in management and follow-up protocols mean that overall cure rates can exceed 98% with fertility retention, whereas most women would have died from malignant disease 60 years ago. This success can be explained by the development of effective treatments, the use of human chorionic gonadotropin as a biomarker, and centralisation of care. We summarise strategies for management of gestational trophoblastic disease and address some of the controversies and future research directions.

Histopathological diagnosis of hydatidiform mole: contemporary features and clinical implications

Gestational trophoblastic neoplasia (GTN) encompasses several entities including complete (CHM) and partial (PHM) hydatidiform mole (HM), malignant choriocarcinoma, and placental-site trophoblastic tumor. HMs are genetically abnormal, nonviable conceptions, which are associated with significantly increased risk for development of complications due to persistence of abnormal trophoblast (persistent GTN; pGTN), which occurs following 15% of CHM and 0.5% of PHM. Diagnostic histological features of HM are present in the first trimester but these features differ from those traditionally described in the later second trimester. The characteristic morphological findings of early HM include aspects of villous dysmorphism and abnormal villous trophoblast hyperplasia, with other specific features allowing reliable distinction between CHM and PHM. Optimal management of molar disease depends on its early histological identification and subsequent surveillance by measurement of maternal human chorionic gonoadotropin (hCG) for detection of pGTN based on rising or plateuing hCG levels such that early effective treatment is possible.

Fetal and placental malignancies: prenatal diagnosis and management

Fetal and placental malignancies are rare complications during pregnancy, but when they occur they may present significant challenges for the perinatology team. Owing to their rarity, there is limited information on many of these entities, with much data derived from individual case reports or small case series. Prenatal diagnosis of these entities is rare and inconsistent, usually in the form of isolated case reports. In the majority of fetal tumors, prenatal features are those of a mass lesion, with or without other non-specific features of fetal compromise such as polyhydramnios, fetal hydrops or intrauterine death, the final diagnosis in most cases being based on postnatal pathological examination.Expectant management is almost always indicated antenatally, with serial ultrasound examinations performed to detect rapid enlargement, metastasis or secondary fetal complications, such as non-immune hydrops, which may require intervention. Delivery should be planned in a specialist center in conjunction with pediatric surgeons and oncologists to allow appropriate neonatal management. Placental malignancy is most commonly in the form of gestatational trophoblastic disease, which requires assessment and management in specialist centers.