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.

Ki-67 expression in hydatidiform moles and hydropic abortions

Background

Differential diagnosis of hydatidiform moles from non-molar specimens as well as their sub-classification such as complete and partial hydatidiform moles are important for clinical management and accurate risk assessment for persistent gestational trophoblastic disease, but diagnosis based solely on histomorphology suffers from poor interobserver and intraobserver reproducibility.

Objectives

This study was undertaken to determine whether the expression of Ki-67 protein could differentiate these entities.

Materials and Methods

We performed Ki-67 immunohistochemical staining in 19 molar (8 partial and 11 complete moles) and 10 non-molar (hydropic abortions) formalin-fixed, paraffin-embedded tissue samples. Ploidy analysis using flow cytometry had confirmed diploidy in hydropic abortions and complete moles and triploidy in partial moles.

Results

Ki-67 immunoreactivity was assessed in villous cytotrophoblasts, syncytiotrophoblasts and stromal cells. Positive cells were found to be restricted mostly to the villous cytotrophoblasts, while syncytiotrophoblasts showed an absence of immunostaining for Ki-67, and occasional weak nuclear staining was seen in the stromal cells. There was a significant difference in Ki-67 immunoreactivity of cytotrophoblastic cells between hydropic abortions and complete moles (P < 0.001), hydropic abortions and partial moles (P = 0.002) and also between complete and partial moles (P < 0.001). On the other hand, there is significant overlap in the Ki-67 immunoreactivity between complete and partial moles (++ staining category) and between partial moles and hydropic abortions (+ staining category).

Conclusions

Despite the significant differences , Ki-67 immunostaining could not be helpful in distinguishing molar placentas from hydropic abortions as well as partial from complete hydatidiform moles, because there are considerable overlaps between results in different categories.

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.

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.

Routine pre-evacuation ultrasound diagnosis of hydatidiform mole: experience of more than 1000 cases from a regional referral center

OBJECTIVES

To examine the accuracy of sonographic findings of routine ultrasound examinations in patients with a proven histological diagnosis of complete or partial hydatidiform mole referred to a supra-regional referral center, and to examine the relationship of sonographic findings to gestational age across the first and early second trimesters.

METHODS

Review of consecutive cases referred to a trophoblastic disease unit from June 2002 to January 2005 with a diagnosis of possible or probable hydatidiform mole in whom results of a pre-evacuation ultrasound examination were documented. Ultrasound detection rates for partial and complete hydatidiform moles were calculated and comparison of detection rates between complete and partial mole, and gestational age groups carried out.

RESULTS

1053 consecutive cases were examined. The median maternal age was 31 (range, 15-54) years and the median gestational age was 10 (range, 5-27) weeks. 859 had a final review diagnosis of partial or complete hydatidiform mole (82%), including 253 (29%) complete moles and 606 (71%) partial moles. Non-molar hydropic miscarriage was diagnosed following histological review in 194 (18%). Overall, 378 (44%) cases with a final diagnosis of complete or partial hydatidiform mole had a pre-evacuation ultrasound diagnosis suggesting hydatidiform mole, including 200 complete moles and 178 partial moles, representing 79% and 29%, respectively, of those with complete (253) or partial (606) moles in the final review diagnosis. The ultrasound detection rate was significantly better for complete versus partial hydatidiform moles (Z = 13.4, P < 0.001). There was a non-significant trend towards improved ultrasound detection rate with increasing gestational age, with an overall detection rate of 35-40% before 14 weeks' gestation compared to around 60% after this gestation. The sensitivity, specificity, positive predictive value and negative predictive value for routine pre-evacuation ultrasound examination for detection of hydatidiform mole of any type were 44%, 74%, 88% and 23%, respectively.

CONCLUSIONS

Routine pre-evacuation ultrasound examination identifies less than 50% of hydatidiform moles, the majority sonographically appearing as missed or incomplete miscarriage. Detection rates are, however, higher for complete compared to partial moles, and improve after 14 weeks' gestation. Histopathological examination of products of conception remains the current gold standard for the identification of gestational trophoblastic neoplasia.

First trimester diagnosis of partial mole

BACKGROUND

Partial mole is one of the two distinctive subtypes of hydatidiform mole. It is usually paternally derived triploid conceptions in which embryonal development occurs in association with trophoblastic hyperplasia. The definite diagnosis is confirmed by pathological and cytogenetic studies. Ultrasound might be helpful to diagnose partial mole in the first trimester.

CASE

A 25-year-old woman, gravida 2, para 0-0-1-0, was initially seen for antenatal care at 6 weeks' pregnant. Ultrasound was undertaken at 13 weeks' pregnancy due to her first fetal anomaly, which demonstrated partial mole and embryonic death. The serum beta hCG was 190,900 mIU/ml. Suction curettage was performed without complication. Histopathological study confirmed partial mole and cytogenetic study of the placenta revealed an uncommon karyotype, mosaicism of triploid (69,XXX/69,XXY). Serum beta hCG was declined and negative at 8 weeks. The patient was well and serum beta hCG remained normal throughout 6 months of follow-up.

CONCLUSION

Although the majority of partial mole pregnancies cannot be detected by routine first trimester ultrasound examination, first trimester ultrasound can be helpful in some cases, such as this one. If partial mole is sonographically suspected, it should be confirmed with histopathology and cytogenetic studies. The management is similar to complete mole including prompt evacuation and careful monitoring of beta hCG.