Persistent trophoblast disease following partial molar pregnancy

Thyrotoxicosis due to Gestational Trophoblastic Disease: Unmet Needs in the Management of Gestational Thyrotoxicosis

Thyrotoxicosis during pregnancy is rare but can have severe adverse consequences for the mother or foetus if left undiagnosed and untreated. It can be caused by an underlying thyroid disease or develop as gestational transient thyrotoxicosis. Molar pregnancy stands out as a pathological condition characterized by abnormal trophoblastic cell growth, which can manifest in benign or malignant forms, and is diagnosed with a disproportionate elevation of β-hCG (beta-human chorionic gonadotrophin) and specific features on ultrasonography including absent sac and large multicystic or honeycomb appearance. A pronounced increase in β-hCG levels can trigger hyperthyroidism, due to the structural resemblance between β-hCG and thyroid-stimulating hormone (TSH), although the thyrotrophic effects of β-hCG could vary between patients diagnosed with gestational trophoblastic disease (GTD). In this report, we present two cases (Patient 1: 43 years, Patient 2: 31 years) who came to emergency department following a history of vaginal spotting, palpitations, and hyperemesis. In both patients, blood tests indicated disproportionately elevated β-hCG levels along with high levels of Free T4 (FT4) and Free T3 (FT3), as well as suppressed TSH levels. Ultrasonography showed nonviable products of conception with large multicystic hemorrhagic lesions and empty gestational sacs, thereby confirming GTD. The Burch-Wartofsky Point Scale scores were 20 and 15 points, respectively, suggesting that they were less likely to be in thyroid storm at presentation. Antithyroid medications were administered, followed by evacuation of the products of conception. Postoperatively, their thyroid function was normalized. These cases underscore the importance of ruling out thyroid storm, monitoring thyroid function, and treating hyperthyroidism appropriately before undergoing surgical treatment. It is also important to consider the variability in the thyrotrophic effects of β-hCG among individuals diagnosed with GTD. In addition to monitoring free thyroid hormone levels, it is crucial to consider clinical symptoms to effectively manage such cases.

A Complete Hydatidiform Mole Complicated by Theca Lutein Cysts in a Teenager: A Rare Case

A hydatidiform mole (HM), often known as molar pregnancy, is a type of prenatal trophoblastic illness that develops in the placenta and has the potential to spread. HMs are caused by genetic issues with either the egg or the sperm. They are typically discovered in the first trimester of pregnancy. Abnormal bleeding is one of the initial symptoms, which can seldom be accompanied by the passage of hydropic villi. Theca lutein cysts, absent fetal heart tones, enlarged uterus more than anticipated for gestational age, pregnancy-induced hypertension in the first trimester, hyperemesis, and increased levels of human chorionic gonadotropin (HCG) for gestational dates are other characteristic symptoms and signs. A rare type of follicular cyst known as a theca lutein cyst is a benign ovarian disease caused by natural overstimulation of follicles, also known as hyperreactio lutealis (HL). This is linked to choriocarcinomas, multiple gestations, and prenatal trophoblastic illness (molar pregnancy). Unless exacerbated by torsion, rupture, or bleeding, the majority of theca lutein cysts are treated conservatively. Theca lutein cysts do not impact the course of pregnancy and spontaneously recede following delivery. However, HL may mistakenly be diagnosed by doctors as a cancer during pregnancy if it has the potential to look like one. Frequently, inappropriate surgical intervention is caused by the fear of failing to diagnose malignancy. These treatments may therefore result in decreased fertility in the future. Here we present a case of a young unmarried female with an HM and cysts.

Loss of p57 Expression in Conceptions Other Than Complete Hydatidiform Mole: A Case Series With Emphasis on the Etiology, Genetics, and Clinical Significance

Combined p57 immunohistochemistry and DNA genotyping refines classification of products of conception specimens into specific types of hydatidiform moles and various nonmolar entities that can simulate them. p57 expression is highly correlated with genotyping and in practice can reliably be used to identify virtually all complete hydatidiform moles (CHM), but aberrant retained or lost p57 expression in rare CHMs and partial hydatidiform moles (PHM), as well as loss in some nonmolar abortuses, has been reported. Among a series of 2329 products of conceptions, we identified 10 cases for which loss of p57 expression was inconsistent with genotyping results (none purely androgenetic). They displayed a spectrum of generally mild abnormal villous morphology but lacked better developed features of CHMs/early CHMs, although some did suggest subtle forms of the latter. For 5 cases, genotyping (4 cases) and/or ancillary testing (1 case) determined a mechanism for the aberrant p57 results. These included 3 PHMs-2 diandric triploid and 1 triandric tetraploid-and 1 nonmolar specimen with loss of p57 expression attributable to partial or complete loss of the maternal copy of chromosome 11 and 1 nonmolar specimen with Beckwith-Wiedemann syndrome. For 5 cases, including 2 diandric triploid PHMs and 3 biparental nonmolar specimens, genotyping did not identify a mechanism, likely due to other genetic alterations which are below the resolution of or not targeted by genotyping. While overdiagnosis of a PHM as a CHM may cause less harm since appropriate follow-up with serum β-human chorionic gonadotropin levels would take place for both diagnoses, this could cause longer than necessary follow-up due to the expectation of a much greater risk of persistent gestational trophoblastic disease for CHM compared with PHM, which would be unfounded for the correct diagnosis of PHM. Overdiagnosis of a nonmolar abortus with loss of p57 expression as a CHM would lead to unnecessary follow-up and restriction on pregnancy attempts for patients with infertility. Genotyping is valuable for addressing discordance between p57 expression and morphology but cannot elucidate certain mechanisms of lost p57 expression. Future studies are warranted to determine whether chromosomal losses or gains, particularly involving imprinted genes such as p57, might play a role in modifying the risk of persistent gestational trophoblastic disease for PHMs and nonmolar conceptions that are not purely androgenetic but have some abnormal paternal imprinting of the type seen in CHMs.

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.

Hyperthyroidism in molar pregnancy: β-HCG levels do not always reflect severity

BACKGROUND

Molar pregnancy is a complication characterised by abnormal benign or malignant proliferation of trophoblastic cells resulting in markedly elevated β-hCG (human chorionic gonadotrophin) levels, an established marker for the presence of the disease. Owing to the structural homology between β-hCG and TSH, the raised β-hCG can result in secondary hyperthyroidism.

METHODS

Two patients aged 20 (Case 1) and 31 years (Case 2) presented to the emergency department within a few days of each other complaining of vaginal bleeding associated with abdominal pain. Ultrasound evaluation, β-hCG and thyroid function tests were performed on both patients.

RESULTS

Both had elevated β-hCG levels and ultrasound evidence of molar pregnancy and were diagnosed with gestational trophoblastic disease (GTD) associated with hyperthyroidism based on thyroid function test results. Case 1 had lower β-hCG levels and free T4 levels compared with Case 2 but clinical assessment of the former revealed severe illness and more complicated course with the development of a thyroid storm. Case 2 had β-hCG levels almost double those of Case 1, yet was stable and her levels decreased much faster, reaching and maintaining undetectable levels.

CONCLUSIONS

These cases demonstrate that the β-hCG levels do not always correlate with disease severity and prognosis in patients with GTD.

Diagnosis and outcome of hydatidiform moles in missed-miscarriage: a cohort-study, systematic review and meta-analysis

OBJECTIVE

To evaluate the ultrasound diagnostic rates of complete hydatidiform moles (CHM) and partial hydatidiform moles (PHM) in women presenting with a missed miscarriage, the clinical complications at diagnosis and the risk of gestational trophoblastic neoplasia (GTN) after surgical evacuation and to compare our findings with those of the published literature by completing a systematic review and meta-analysis STUDY DESIGN: Retrospective review of the data of 295 women diagnosed with a histologically confirmed hydatidiform moles (HM) over a 15-year period, including 128 CHM and 167 PHM. All women were referred to a regional specialist centre for follow-up and further management. An electronic search of PubMed, Google Scholar and MEDLINE was performed for studies published between September 1973 and September 2017 reporting on the early ultrasound diagnosis of hydatidiform mole. Only cohort studies which provided ultrasound data confirmed by histopathology were included.

RESULTS

In the cohort study, ultrasound imaging diagnosed a significantly (p < 0.001) higher number of CHM (95/128 (74.2%) than PHM (68/167 (40.7%). Ovarian theca lutea cysts were observed in three CHM and one PHM. There were no cases of pre-eclampsia or thyrotoxicosis at the time of diagnosis. Maternal serum β-human chorionic gonadotrophin levels were abnormally low (< 0.5 MoM) in 5/51 (10%) CHM and 23/43 (53%) PHM and abnormally high (> 2.0 MoM) in 20/51 (39%) CHM and 2/43 (5%) PHM. Seventeen (12.3%) CHM and two (1.4%) PHM developed a GTN requiring treatment. In the literature the proportion of histologically diagnosed HM, suspected on ultrasound in early pregnancy, ranged between 34.2 and 90.2% for HM, 57.8 and 95% for CHM and 17.6 and 51.6% for PHM. The meta-analysis indicated substantial heterogeneity in the overall ultrasound diagnosis of HM and in the differential diagnosis between CHM and PHM.

CONCLUSION(S)

As around a third of CHM and two thirds of PHM are not diagnosed on ultrasound in cases of missed miscarriage, histopathological examination of all products of conception in case of early pregnancy failure is essential to detect molar changes. This is particularly important for the management of women with CHM who have a higher risk of developing a GTN.

Gestational Trophoblastic Neoplasia After Human Chorionic Gonadotropin Normalization Following Molar Pregnancy

OBJECTIVE

To estimate the incidence of gestational trophoblastic neoplasia following complete and partial molar pregnancy after reaching normal human chorionic gonadotropin (hCG) levels to guide evidence-based follow-up recommendations.

DATA SOURCES

MEDLINE, EMBASE, Web of Science, POPLINE, Cochrane, and ClinicalTrials.gov were searched from inception to November 2018, using the intersection of "gestational trophoblastic disease," "molar pregnancy," and "human chorionic gonadotropin" themes.

METHODS OF STUDY SELECTION

Search results were screened to identify cohort studies of molar pregnancy reporting gestational trophoblastic neoplasia development, with at least 6 months of intended normal hCG follow-up.

TABULATION, INTEGRATION, AND RESULTS

Two reviewers independently identified articles for inclusion. Data were extracted using a standardized form. For meta-analysis, cumulative incidence of gestational trophoblastic neoplasia, with CIs by the Agresti-Coull method, and pooled risk ratios (RRs) comparing complete and partial mole were calculated. Among the 19 eligible studies that reported adequate data for inclusion in the primary meta-analysis, we found low incidence of gestational trophoblastic neoplasia after normal hCG level following both complete mole (64/18,357, 0.35%, 95% CI 0.27-0.45%), and partial mole (5/14,864, 0.03%, 95% CI 0.01-0.08%). There was a significantly higher risk of gestational trophoblastic neoplasia after complete compared with partial molar pregnancy (RR 4.72, 95% CI 1.81-12.3, P=.002). Among gestational trophoblastic neoplasia cases after normal hCG level following complete mole, 89.6% occurred when the time from evacuation to normalization was 56 days or longer, and 60.7% were diagnosed beyond the commonly recommended 6-month surveillance interval. Sensitivity analyses, including those limiting to studies at low risk of bias, did not significantly affect results. We found an overall incidence of gestational trophoblastic neoplasia of 15.7% for complete mole (1,354/8,611, 95% CI 15.0-16.5%) and 3.95% for partial mole (221/5,593, 95% CI 3.47-4.50%).

CONCLUSION

Gestational trophoblastic neoplasia development after normal hCG level following molar pregnancy is rare. Recommendations for frequency and duration of hCG follow-up can be minimized to lessen burden on patients and informed by the type of molar pregnancy and time interval from uterine evacuation to hCG normalization.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42019116414.

Paternal uniparental isodisomy of tyrosine hydroxylase locus at chromosome 11p15.4: spectrum of phenotypical presentations simulating hydatidiform moles

Uniparental disomy is an abnormal genetic condition in which both homologous chromosomes or part of the chromosome are inherited from one parent and the other parent's homologous chromosome is lost. We report three cases of gestations with paternal uniparental isodisomy at tyrosine hydroxylase or TH01 locus on chromosome 11p15.4 identified by DNA genotyping. The patients' age ranged from 32 to 35 years and all patients presented with missed abortion during the first trimester. Abnormal chorionic villi were seen in all cases with histomorphological and/or p57 immunohistochemical features simulating either partial or complete mole. While two patients had an uneventful clinical course, one patient presented with clinical complications simulating persistent gestational trophoblastic disease/neoplasia that required multiagent chemotherapy with etoposide, methotrexate, actinomycin D, vincristine, and cyclophosphamide (EMA-CO). In summary, paternal uniparental isodisomy of tyrosine hydroxylase locus at chromosome 11p15.4 may result in an abnormal gestation that simulates a hydatidiform mole both clinically and histologically. The presence of abnormal trophoblastic proliferation combined with loss of p57 expression in villous cytotrophoblast and stromal cells may be associated with an aggressive clinical behavior.

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.

Changing Trends in the Clinical Presentation and Management of Complete Hydatidiform Mole Among Brazilian Women

OBJECTIVE

The aim of the study was to evaluate potential changes in the clinical, diagnostic, and therapeutic parameters of complete hydatidiform mole in the last 25 years in Brazil.

METHODS

A retrospective cohort study was conducted involving the analysis of 2163 medical records of patients diagnosed with complete hydatidiform mole who received treatment at the Rio de Janeiro Reference Center for Gestational Trophoblastic Disease between January 1988 and December 2012. For the statistical analysis of the natural history of the patients with complete molar pregnancies, time series were evaluated using the Cox-Stuart test and adjusted by linear regression models.

RESULTS

A downward linear temporal trend was observed for gestational age of complete hydatidiform mole at diagnosis, which is also reflected in the reduced occurrence of vaginal bleeding, hyperemesis and pre-eclampsia. We also observed an increase in the use of uterine vacuum aspiration to treat molar pregnancy. Although the duration of postmolar follow-up was found to decline, this was not accompanied by any alteration in the time to remission of the disease or its progression to gestational trophoblastic neoplasia.

CONCLUSIONS

Early diagnosis of complete hydatidiform mole has altered the natural history of molar pregnancy, especially with a reduction in classical clinical symptoms. However, early diagnosis has not resulted in a reduction in the development of gestational trophoblastic neoplasia, a dilemma that still challenges professionals working with gestational trophoblastic disease.

Morphological Features and Immunohistochemical Expression of p57Kip2 in Early Molar Pregnancies and Their Relations to the Progression to Persistent Trophoblastic Disease

Background

Although the morphological features characteristic of products of conception specimens including molar pregnancies are well described, substantial histopathological similarities are observed between the different entities, especially in cases of early pregnancies. Furthermore, there are no current solid criteria that could predict cases with progression to persistent gestational trophoblastic disease. In this study, we aimed to determine the most specific histopathological and immunohistochemical features required for accurate diagnosis that can reliably predict the clinical behavior.

Methods

Sixty-five cases of products of conception were reviewed clinically and pathologically, and any progression to persistent gestational trophoblastic disease (GTD), if present, was noted. Pathological assessment of the archival material included re-cut sections of 5 μm in thickness, routine staining with hematoxylin and eosin and immunohistochemical staining of p57Kip2.

Results

Certain histopathological criteria were found to be significant in differentiation between complete hydatidiform mole (CHM) and partial hydatidiform mole including villous shape and outline, villous trophoblast hyperplasia, and atypia in extravillous trophoblasts. There were no significant differences in any morphological or immunohistochemical features between cases with or without subsequent development of GTD.

Conclusions

Histopathological diagnosis of molar pregnancy remains problematic especially in early gestation. Their diagnosis should be stated after a constellation of specific histopathological criteria in order not to miss CHM. p57Kip2 immunohistochemistry is of great value in diagnosis of cases that had equivocal morphology by histopathological examination. However, there were no significant features to predict cases that subsequently developed persistent GTD.

Women with a partial mole during their first pregnancy and diagnosed earlier in gestation are at increased risk of developing gestational trophoblastic neoplasia

OBJECTIVE

The aim of this study is to identify factors associated with gestational trophoblastic neoplasia (GTN) after partial molar pregnancy.

METHODS

We retrospectively evaluated clinical data from 111 patients with a partial molar pregnancy between 1995 and 2010.

RESULTS

A total of 111 patients with a partial molar pregnancy were available for analysis. There was no significant difference between patients who did and did not develop GTN with respect to patient age, parity, history of prior molar pregnancy, presenting signs/symptoms, uterine size greater than gestational age, clinical diagnosis, preevacuation sonogram findings, or the preevacuation human chorionic gonadotropin value. Patients who developed GTN had fewer prior pregnancies (median, 2 vs 3; P = 0.02) and were more likely to have had a partial molar pregnancy as their first gestational event (37.1% vs 17.1%; P = 0.03). Among the 35 patients who developed GTN, the median time to diagnosis of GTN was 47 days (range, 25-119 days), and the median human chorionic gonadotropin value at the time of GTN diagnosis was 475 mIU/mL (range, 20-52,630 mIU/mL). All women (100%) who developed GTN had stage I disease, and all patients (100%) had low-risk GTN. All 35 women (100%) were able to achieve remission, and most (85.7%) of these patients received methotrexate as first-line chemotherapy.

CONCLUSIONS

Women with a partial molar pregnancy as their first gestational event and diagnosed earlier in gestation are more likely to develop postmolar GTN.

Characteristics of hydatidiform moles: analysis of a prospective series with p57 immunohistochemistry and molecular genotyping

Immunohistochemical analysis of cyclin-dependent kinase inhibitor 1C (CDKN1C, p57, Kip2) expression and molecular genotyping accurately classify hydatidiform moles into complete and partial types and distinguish these from non-molar specimens. Characteristics of a prospective series of all potentially molar specimens encountered in a large gynecologic pathology practice are summarized. Initially, all specimens were subjected to both analyses; this was later modified to triage cases for genotyping based on p57 results: p57-negative cases diagnosed as complete hydatidiform moles without genotyping; all p57-positive cases genotyped. Of the 678 cases, 645 were definitively classified as complete hydatidiform mole (201), partial hydatidiform mole (158), non-molar (272), and androgenetic/biparental mosaic (14); 33 were unsatisfactory, complex, or problematic. Of the 201 complete hydatidiform moles, 104 were p57-negative androgenetic and an additional 95 were p57-negative (no genotyping), 1 was p57-positive (retained maternal chromosome 11) androgenetic, and 1 was p57-non-reactive androgenetic; 90 (85%) of the 106 genotyped complete hydatidiform moles were monospermic and 16 were dispermic. Of the 158 partial hydatidiform moles, 155 were diandric triploid, with 154 p57-positive, 1 p57-negative (loss of maternal chromosome 11), and 1 p57-non-reactive; 3 were triandric tetraploid, with 2 p57-positive and 1 p57-negative (loss of maternal chromosome 11). Of 155 diandric triploid partial hydatidiform moles, 153 (99%) were dispermic and 2 were monospermic. Of the 272 non-molar specimens, 259 were p57-positive biparental diploid, 5 were p57-positive digynic triploid, 2 were p57-negative biparental diploid (no morphological features of biparental hydatidiform mole), and 6 were p57-non-reactive biparental diploid. Of the 14 androgenetic/biparental mosaics with discordant p57 expression, 6 were uniformly mosaic and 8 had a p57-negative androgenetic molar component. p57 expression is highly correlated with genotyping, serves as a reliable marker for diagnosis of complete hydatidiform moles, and identifies androgenetic cell lines in mosaic conceptions. Cases with aberrant and discordant p57 expression can be correctly classified by genotyping.

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.

Diagnostic reproducibility of hydatidiform moles: ancillary techniques (p57 immunohistochemistry and molecular genotyping) improve morphologic diagnosis

Distinction of hydatidiform moles (HMs) from nonmolar specimens (NMs) and subclassification of HMs as complete hydatidiform moles (CHMs) and partial hydatidiform moles (PHMs) are important for clinical practice and investigational studies; yet, 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, and 26 NMs) were selected from a series of 200 potentially molar specimens previously diagnosed using p57 immunostaining and genotyping. Cases were classified by 3 gynecologic pathologists on the basis of H&E slides (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) were determined. Genotyping results were used as the gold standard for assessing diagnostic performance. Sensitivity of a diagnosis of CHM ranged from 59% to 100% for individual pathologists and from 70% to 81% by consensus; specificity ranged from 91% to 96% for individuals and from 94% to 98% by consensus. Sensitivity of a diagnosis of PHM ranged from 56% to 93% for individual pathologists and from 70% to 78% by consensus; specificity ranged from 58% to 92% for individuals and from 74% to 85% by consensus. The percentage of correct classification of all cases by morphology ranged from 55% to 75% for individual pathologists and from 70% to 75% by consensus. The κ values for interobserver agreement ranged from 0.59 to 0.73 (moderate to good) for a diagnosis of CHM, from 0.15 to 0.43 (poor to moderate) for PHM, and from 0.13 to 0.42 (poor to moderate) for NM. The κ values for intraobserver agreement ranged from 0.44 to 0.67 (moderate to good). Addition of the p57 immunostain improved sensitivity of a diagnosis of CHM to a range of 93% to 96% for individual pathologists and 96% by consensus; specificity was improved from a range of 96% to 98% for individual pathologists and 96% by consensus; there was no substantial impact on diagnosis of PHMs and NMs. Interobserver agreement for interpretation of the p57 immunostain was 0.96 (almost perfect). Even with morphologic assessment by gynecologic pathologists and p57 immunohistochemistry, 20% to 30% of cases will be misclassified, and, in particular, distinction of PHMs and NMs will remain problematic.

Diandric triploid hydatidiform mole with loss of maternal chromosome 11

Distinction of hydatidiform moles (HM) from nonmolar specimens and their subclassification as complete (CHM) versus partial hydatidiform mole (PHM) are important for clinical practice and investigational studies to refine ascertainment of risk of persistent gestational trophoblastic disease (GTD), which differs among these entities. Immunohistochemical analysis of p57 expression, a paternally imprinted maternally expressed gene on 11p15.5, and molecular genotyping are useful for improving diagnosis. CHMs are characterized by androgenetic diploidy, with loss of p57 expression due to lack of maternal DNA. Loss of p57 expression distinguishes CHMs from both PHMs (diandric triploidy) and nonmolar specimens (biparental diploidy), which retain expression. We report a unique HM characterized by morphologic features suggesting an early CHM, including lack of p57 expression by immunohistochemistry, but with genetic features more in keeping with a PHM. Specifically, molecular genotyping by short tandem repeat markers provided evidence to support interpretation as a PHM by demonstrating allele patterns and ratios most consistent with diandric triploidy, with evidence of loss of the maternal copy of chromosome 11 to explain the lack of p57 expression. This case illustrates the value of combined traditional pathologic and ancillary molecular techniques for refined diagnosis of molar specimens. It also raises questions regarding which modalities should be used to ultimately define the subtypes of HMs and whether chromosomal losses or gains, particularly involving imprinted genes such as p57, might play a role in modifying risk of persistent GTD.

Predicting gestational trophoblastic neoplasia (GTN): is urine hCG the answer?

BACKGROUND

Previous studies on the significance of hCG to predict gestational trophoblastic neoplasia (GTN) have been too small for robust conclusions to be reached. Our aim in this study was to analyse the significance of urine hCG in predicting GTN in a large population.

METHODS

Details of 3926 patients were available for analysis. Information regarding age, dates of diagnosis and registration, urine hCG levels, antecedent pregnancy and chemotherapy were prospectively collected and used for analyses. Patients were stratified into different groups according to urine hCG level (IU/L); < 50, 50-99, 100-249, 250-499, 500-999, 1000-9999 and ≥10,000. Multivariate analyses were used to identify the prognostic indicators of GTN.

RESULTS

Urine hCG and antecedent pregnancy were the most powerful indicators for developing GTN (P<0.01). None of the patients with partial mole and urine hCG <50 IU/L (Normal level=40 IU/L) developed GTN. The risk of GTN was >35% in all patients with urine hCG ≥500 IU/L. GTN developed in 70% of patients with complete mole and urine hCG ≥10,000 IU/L.

CONCLUSION

Urine hCG is sensitive test for GTN. Urine hCG level is a powerful prognostic indicator for the GTN. Patients with partial mole could be safely discharged from the surveillance programme once their hCG have normalised. Patients with urine hCG ≥249 IU/L, whether partial or complete molar pregnancy, appear to benefit from intensive surveillance. Prophylactic chemotherapy could be considered when there are problems with surveillance.

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.

Abnormal villous morphology associated with triple trisomy of paternal origin

The vast majority of trisomies in spontaneous abortions (SAB) are single and of maternal origin, most frequently due to meiosis I errors. Triple trisomies are exceedingly rare (approximately 0.05% of spontaneous abortions), most often of maternal origin, and associated with increased maternal age. Some trisomic SAB specimens can exhibit abnormal villous morphology simulating a partial hydatidiform mole, a distinct form of hydatidiform mole characterized by diandric triploidy. A SAB specimen from a 27-year-old woman, G1P0 at 8 weeks gestational age, was reviewed in consultation to address the finding of morphological features suggestive of a partial hydatidiform mole but DNA ploidy analysis yielding a diploid result. The villi were irregularly shaped and hydropic but lacked trophoblastic hyperplasia; p57 expression was retained. Since fully developed features of a partial hydatidiform mole were lacking, additional analysis was performed. Molecular genotyping and single nucleotide polymorphism array analysis demonstrated biparental diploidy with trisomy of chromosomes 7, 13, and 20, all of paternal origin. The three trisomies may have originated from paternal meiosis II errors, or from mitotic nondisjunction. We believe this to be the first report of triple trisomy in a SAB confirmed to be of paternal origin.

Recurrent gestational trophoblastic disease after hCG normalization following hydatidiform mole in The Netherlands

OBJECTIVES

To determine the risk for recurrent trophoblastic disease after spontaneous normalization of human chorionic gonadotropin (hCG) levels in patients with hydatidiform mole and to determine the risk for tumor relapse after apparent remission following chemotherapy in patients with low- and high-risk persistent trophoblastic disease.

METHODS

From 1994 until 2004, 355 patients with hydatidiform mole were registered at the Dutch Central Registry of Hydatidiform Mole and were monitored by sequential hCG assays in serum at the department of Chemical Endocrinology of the Radboud University Nijmegen Medical Centre. HCG regression curves were analyzed together with clinical information collected from the Hydatidiform Mole Database.

RESULTS

Among the 355 registered hydatidiform mole patients, 265 patients attained spontaneous normalization following evacuation. Of the 265 patients, one patient (0.38%) subsequently required chemotherapeutic treatment for recurrent trophoblastic disease (95% confidence interval 0.0% to 2.1%). HCG levels did not decline to normal (<2.0 ng/ml) spontaneously in 90 patients; those patients were subsequently treated. Relapse rates were 8.1% (6/74) and 6.3% (1/16) for the low- and high-risk category respectively.

CONCLUSION

Our analysis indicates that relapse risk in hydatidiform mole patients with spontaneous normalization is extremely low (one in 265 patients) after two normal hCG levels (<2.0 ng/ml) are achieved. Our results support the suggestion that two subsequent normal hCG levels may be sufficient to ensure sustained remission after hydatidiform mole evacuation. In contrary, in order to assure sustained remission, the relapse rates after chemotherapy in the current study emphasize the need for surveillance of trophoblastic tumor patients even after complete remission has apparently been achieved.

Guidelines following hydatidiform mole: A reappraisal

OBJECTIVE

The aim of this study was to determine how often patients with complete hydatidiform mole (CHM) who spontaneously achieve normal human chorionic gonadotrophin (hCG) levels subsequently develop persistent or recurrent gestational trophoblast disease.

METHODS

Four hundred and fourteen cases of CHM registered at the Hydatidiform Mole Registry of Victoria were reviewed retrospectively after molar evacuation. Maternal age, gestational age, gravidity and parity were determined for each patient, as well as the need for chemotherapy.

RESULTS

Among the 414 patients, 55 (13.3%) required chemotherapy for persistent trophoblastic disease. None of the patients whose hCG levels spontaneously fell to normal subsequently developed persistent molar disease.

CONCLUSION

Weekly hCG measurements are recommended for all patients until normal levels are achieved. For patients who attain normal hCG levels within 2 months after evacuation, it seems safe to discontinue monitoring once normal levels are achieved. Patients who fail to achieve normal hCG levels by 2 months after evacuation should be monitored with monthly hCG measurements for 1 year after normalisation to assure sustained remission.