Ki-67 expression in hydatidiform moles and hydropic abortions

Gestational Trophoblastic Disease: Complete versus Partial Hydatidiform Moles

Hydatidiform moles, including both complete and partial moles, constitute a subset of gestational trophoblastic diseases characterized by abnormal fertilization resulting in villous hydrops and trophoblastic hyperplasia with or without embryonic development. This involves chromosomal abnormalities, where one or two sperms fertilize an empty oocyte (complete hydatidiform mole (CHM); mostly 46,XX) or two sperms fertilize one oocyte (partial hydatidiform mole (PHM); mostly 69,XXY). Notably, recurrent occurrences are associated with abnormal genomic imprinting of maternal effect genes such as NLRP7 (chromosome 19q13.4) and KHDC3L (chromosome 6q1). Ongoing efforts to enhance identification methods have led to the identification of growth-specific markers, including p57 (cyclin-dependent kinase inhibitor 1C; CDKN1C), which shows intact nuclear expression in the villous cytotrophoblast and villous stromal cells in PHMs and loss of expression in CHMs. Treatment of hydatidiform moles includes dilation and curettage for uterine evacuation of the molar pregnancy followed by surveillance of human chorionic gonadotropin (HCG) levels to confirm disease resolution and rule out the development of any gestational trophoblastic neoplasia. In this review, we provide a synopsis of the existing literature on hydatidiform moles, their diagnosis, histopathologic features, and management.

Diagnostic Utility of TSSC3 and RB1 Immunohistochemistry in Hydatidiform Mole

The general notion of complete hydatidiform moles is that most of them consist entirely of paternal DNA; hence, they do not express p57, a paternally imprinted gene. This forms the basis for the diagnosis of hydatidiform moles. There are about 38 paternally imprinted genes. The aim of this study is to determine whether other paternally imprinted genes could also assist in the diagnostic approach of hydatidiform moles. This study comprised of 29 complete moles, 15 partial moles and 17 non-molar abortuses. Immunohistochemical study using the antibodies of paternal-imprinted (RB1, TSSC3 and DOG1) and maternal-imprinted (DNMT1 and GATA3) genes were performed. The antibodies' immunoreactivity was evaluated on various placental cell types, namely cytotrophoblasts, syncytiotrophoblasts, villous stromal cells, extravillous intermediate trophoblasts and decidual cells. TSSC3 and RB1 expression were observed in all cases of partial moles and non-molar abortuses. In contrast, their expression in complete moles was identified in 31% (TSSC3) and 10.3% (RB1), respectively (p < 0.0001). DOG1 was consistently negative in all cell types in all cases. The expressions of maternally imprinted genes were seen in all cases, except for one case of complete mole where GATA3 was negative. Both TSSC3 and RB1 could serve as a useful adjunct to p57 for the discrimination of complete moles from partial moles and non-molar abortuses, especially in laboratories that lack comprehensive molecular service and in cases where p57 staining is equivocal.

Partial hydatidiform mole pregnancy ended in full-term delivery of a normal infant: a case presentation

BACKGROUND

Twin pregnancy with a partial hydatidiform mole (PHM) and a coexistent live fetus is extremely rare. The fetus usually has a normal karyotype. The surviving rate of the fetus till lung maturity is only about 25-40%. PHM pregnancy almost ends in abortion due to the presence of triploid embryo. Here, we report a case of PHM coexistent with a live fetus resulting in a live baby.

CASE PRESENTATION

A PHM pregnancy was diagnosed by ultrasonography in a 28-year-old Chinese woman, with normal fetal morphology and mosaicism as indicated by amniocentesis. After being fully informed of the risks, the woman chose to proceed with the pregnancy and finally gave birth to a baby girl and the infant was delivered at term. A single placenta with vesicular changes and peripheral blood diploid chromosomes were observed. There were no serious maternal complications. In conclusion, the diagnosis, management, and monitoring of this condition, which is very rare in clinical practice, remain challenging. Under proper management, a PHM-combined pregnancy can still end in full-term delivery of a normal living fetus.

P53 expression in various types of hydropic placentas (through ploidy analysis as a complementary tool in diagnosis of samples)

BACKGROUND

Placentas characterized by hydropic swelling of chorionic villi occur in a spectrum of pathological conditions including hydropic abortion (HA), partial hydatidiform mole (PHM) and complete hydatidiform mole (CHM). The purpose of this study was to investigate whether the expression of p53 tumour suppressor protein could differentiate these various types of hydropic placentas.

METHODS

p53 immunohistochemical staining was performed in 19 molar (8 PHM and 11 CHM) and 10 non-molar (HA) formalin-fixed, paraffin-embedded tissue samples. Ploidy analysis using flow cytometry was performed as a complementary tool in diagnosis of samples.

RESULTS

DNA histograms obtained from all samples had confirmed diploidy in HAs and CHMs and triploidy in PHMs. p53 immunoreactivity was assessed in villous cytotrophoblasts, syncytiotrophoblasts and stromal cells. The p53 positive reaction was predominantly observed in the nuclei of cytotrophoblastic cells and rarely in stromal cells, no reaction was seen in syncytiotrophoblasts. The mean percentage of p53 positive cells were 6.10±3.75 for HA, 25.87±13.4 for PHM and 39.83±18.76 for CHM. There was a significant difference in P53 immunoreactivity of cytotrophoblastic cells between CHM and HA (P<0.001), and between PHM and HA (P=0.004). There was no significant difference in immunohistochemical reactivity between CHM and PHM (P=0.068).

CONCLUSION

This study confirms that p53 immunostaining may be helpful in distinguishing complete and partial hydatidiform mole from hydropic abortion, but not complete hydatidiform mole from partial hydatidiform mole.

Diagnostic Utility of Twist1, Ki-67, and E-Cadherin in Diagnosing Molar Gestations and Hydropic Abortions

OBJECTIVES

This study aims to assess whether the expression of Twist1, Ki-67, and E-cadherin can guide the differential diagnosis of complete hydatidiform mole (CHM), partial hydatidiform mole (PHM), and hydropic abortion (HA).

METHODS

Differential expression of Twist1, Ki-67, and E-cadherin was analyzed in gestational products from 55 cases of CHM, PHM, and HA using immunohistochemistry. Prior to analysis, the studied cases were confirmed for their diagnosis by flow cytometric assessment of DNA ploidy and p57 immunostaining.

RESULTS

Twist1 expression can distinguish CHM from PHM and HA with 100% sensitivity, 100%, specificity, 100% positive predictive value (PPV), and 100% negative predictive value (NPV). Furthermore, combined Ki-67 and E-cadherin expression could differentiate PHM and HA with 100% sensitivity, 93.3% specificity, 92.3% PPV, and 100% NPV.

CONCLUSIONS

Twist1 expression is a highly reliable marker for the diagnosis of CHM, where combined Ki-67 and E-cadherin immunoreactivity can distinguish PHM from nonmolar pregnancies.

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.

CD71 in Gestational Pathology: A Versatile Immunohistochemical Marker With New Possible Applications

Transferrin receptor/CD71 is a membrane protein expressed on nucleated red blood cells (NRBCs) and trophoblasts. Here, we propose the first study to evaluate the usefulness of CD71 immunolabeling in the main fields of gestational pathology. To this aim, formalin-fixed, paraffin-embedded samples of 45 orthotopic (23 spontaneous abortive and 22 molar pregnancies) and 11 ectopic pregnancies were immunostained for CD71. NRBCs were morphologically evident in 23 cases: 12/23 abortive, 4/11 ectopic, and 7/10 partial molar pregnancies. CD71 immunolabeling detected NRBCs in all 23 previous cases and in 8 new cases: 2 partial moles and 6 spontaneous abortive pregnancies. No NRBCs were detected in complete moles by means of either morphology or immunohistochemistry (IHC). In 4 cases with extensive necrotic changes, CD71 marked NRBCs and a few ghost villi, which were not certainly identifiable with standard histological evaluation. Furthermore, there was an inversely proportional relationship between total percentage of CD71-positive NRBCs and gestational age (R=0.69; P<0.0001). We conclude that CD71 is a robust IHC marker for the detection of NRBCs and chorionic villi, especially in the presence of necrosis. The demonstration of NRBCs can be important in molar pathology, helping to exclude a complete mole. The application of CD71 could improve the diagnosis of this pathology in selected cases in which diffuse necrotic or hemorrhagic aspects may hinder the interpretation of the conventional approach with histology, IHC for p57, and ploidy analysis. Finally, the inverse correlation between the total percentage of CD71-positive NRBCs and gestational age suggests that this analysis may help in pregnancy dating.