Impact of surgery for endometriosis on the outcomes of in vitro fertilization

This narrative review aims to summarize available evidence on the IVF-associated outcomes after surgery for endometriosis. Only one retrospective study investigated if surgical treatment of superficial/peritoneal endometriosis may modify the outcomes of IVF; therefore, more data are needed to confirm the benefit of surgery for this type of disease for improving ART outcomes, and to be able to support it in routine practice. Solid evidence from several meta-analyses demonstrates that surgical treatment of endometriomas does not enhance the outcomes of IVF. In contrast, surgical treatment of ovarian endometriosis may lead to a reduction in ovarian reserve, especially in cases involving bilateral endometriomas or repeated surgical procedures. Some non-randomized studies have examined if surgical treatment on deep endometriosis may influence IVF outcomes. A systematic review with meta-analysis revealed that patients who underwent surgery before IVF exhibited significantly higher pregnancy rates per patient, pregnancy rates per cycle, and live birth rates per patient compared to those without prior surgery. However, the available data are insufficient to recommend surgical excision of deep endometriosis as the first-line treatment for asymptomatic patients to enhance IVF outcomes.

Histological analysis of (antral) follicle density in ovarian cortex tissue attached to stripped endometriomas

PURPOSE

When resecting endometriomas with the stripping technique, in the majority of cases, a thin line of adjacent ovarian cortex is attached to the endometrioma. In this study, we performed histological analysis to determine (antral) follicle density in the ovarian cortex tissue attached to stripped endometriomas and assessed patient- and surgical characteristics that could affect this.

METHODS

Histological slides of previously removed endometriomas were assessed. Follicles in the attached ovarian tissue were classified according to maturation, and follicular density was determined. Immunofluorescent staining of antral follicles in a subset of endometriomas was also performed.

RESULTS

In 90 out of 96 included endometriomas (93.7%), ovarian tissue attached to the cyst wall was observed. One thousand nine hundred forty-four follicles at different maturation stages were identified (3 follicles/mm3). Follicle density was negatively associated with age (p < 0.001). Antral follicles (< 7-mm diameter) were present in the ovarian tissue attached to 35 endometriomas (36.5%) derived from younger patients compared to endometriomas where none were detected (30 versus 35 years, p = 0.003). Antral follicle density was 1 follicle/mm3. Based on immunofluorescence, healthy antral follicles were identified in two out of four examined endometriomas.

CONCLUSIONS

Ovarian tissue attached to stripped endometriomas holds potential as a non-invasive source for antral follicles. In theory, application of IVM could be an interesting alternative FP option in young patients with endometriomas who undergo cystectomy in order to transform the surgical collateral damage to a potential oocyte source. Our results encourage future research with fresh tissue to further assess the quality and potential of these follicles.

TRIAL REGISTRATION

Clinical Trials.gov Identifier: B21.055 (METC LDD), date of registration 12-08-2021, retrospectively registered.

Downregulation of lncRNA LINC01465 predicts ovarian endometriosis and its prognosis

The well-known impact of ovarian endometriosis on female quality of life and the established role of lncRNA LINC01465 in ovarian cancer pathogenesis have been extensively documented; however, the relationship between LINC01465 and ovarian endometriosis is still not clear. This study seeks to explore the potential involvement of LINC01465 in the disease. The study analyzed a sample of 80 endometriosis patients and 80 healthy women. The expression of LINC01465 was measured in ectopic and eutopic endometrial tissues through RT-qPCR. The diagnostic potential of serum LINC01465 levels was evaluated using ROC curve analysis, and the patients were followed up for 3 years after treatment to monitor recurrence. The results revealed that the expression of LINC01465 was significantly lower in ectopic endometrial tissues in comparison to paired eutopic tissues for most of the patients. No correlation was found between the patient's age or lifestyle and serum LINC01465 levels. After treatment, the serum LINC01465 level increased, and patients who experienced recurrence had significantly lower levels compared to those who did not. In conclusion, the study findings suggest that the downregulation of LINC01465 plays a role in the pathogenesis of ovarian endometriosis and may serve as a diagnostic and prognostic biomarker for the disease.

Serum miRNA as a predictive biomarker for ovarian reserve after endometrioma-cystectomy

Ovarian endometrioma (OE) is a common gynecological disease that is often treated with surgery and hormonal treatment. However, ovarian cystectomy can impair the ovarian reserve (OR). Previously, we showed that perioperative administration of dienogest (DNG) is an effective option for OR preservation. However, there were differences in the extent of OR preservation among patients following perioperative DNG treatment. In the current study, we performed a global examination of serum microRNAs (miRNAs) to identify accurate biomarkers that predict post-operative restoration of OR following perioperative DNG treatment. We also sought to identify specific miRNAs related to the anti-Müllerian hormone (AMH). miRNA sequencing was performed on serum samples obtained from twenty-seven patients who received perioperative DNG treatment. Candidate miRNAs were selected by comparing patients whose ORs were restored postoperatively (responder group, n = 7) with those whose ORs were not (non-responder group, n = 7). miR-370-3p and miR-1307-3p were significantly upregulated in the responder group, whereas miR-27b-3p was upregulated in the non-responder group. The pretreatment value of each miRNA could predict DNG responsiveness for OR following ovarian cystectomy (area under the curve [AUC] > 0.8). The quantitative polymerase chain reaction (qPCR) revealed only miR-1307-3p was found to be significantly upregulated in the responder group (P < 0.05). In addition, we identified miR-139-3p, miR-140-3p, and miR-629-5p as AMH-associated miRNAs. The transition of AMH showed a correlation with miR-139-3p (P < 0.05, r = -0.76). The miRNAs identified herein represent potential serum biomarkers of clinical value in predicting OR prior to DNG treatment.

Galectin-3 promotes fibrosis in ovarian endometriosis

Objective

This study aimed to investigate the potential role of galectin-3 (Gal-3) in the pathogenesis of fibrotic alterations in ovarian endometriosis (OVE).

Methods

In this study, we collected the ectopic endometrial tissues and eutopic endometrial tissues from 31 OVE patients treated by laparoscopy, and the eutopic endometrial tissues from 23 non-OVE patients with leiomyoma or other benign diseases were used as control. Hematoxylin and eosin (H&E) and Masson's trichrome staining were utilized for histopathological assessment. The primary normal endometrial stromal cells (NESC), ectopic endometrial stromal cells (ECSC), and eutopic endometrial stromal cells (EUSC) were isolated. Gal-3 overexpression plasmids (Gal-OE) and short hairpin RNA targeting Gal-3 (Gal-3-shRNA) were transfected into the immortalized human endometriotic cell line 12Z, respectively. RT-qPCR, Western blot analysis, and immunohistochemistry were used to detect the mRNA and protein expression levels of Gal-3, type I collagen (COL-1), connective tissue growth factor (CTGF) and α-smooth muscle actin (α-SMA), respectively.

Results

H&E and Masson staining showed that ovarian ectopic endometrium exhibited glandular hyperplasia, high columnar glandular epithelium, apical plasma secretion, more subnuclear vacuoles, and obvious fibrosis, compared with normal endometrium. The mRNA and protein levels of Gal-3 , CTGF, α-SMA, and COL-1 were all upregulated in the ectopic endometrial tissues of OVE patients compared to the eutopic endometrial tissues from OVE patients and non-OVE patients. Moreover, ECSC expressed higher levels of Gal-3, CTGF, α-SMA, and COL-1 than EUSC and NESC. Follow-up investigations demonstrated that the Gal-3 overexpression substantially increased fibrosis-related markers including CTGF, α-SMA, and COL-1 within the 12Z cell line. Conversely, Gal-3 knockdown showed the opposite effects.

Conclusion

Gal-3 promotes fibrosis in OVE, positioning it as a prospective therapeutic target for mitigating fibrosis in endometriosis.

Comparison of serum anti-Müllerian hormone between unilateral and bilateral ovarian endometriomas during follicular, luteal, and random menstrual phases: a retrospective study

BACKGROUND

Over the last two decades, serum levels of anti-Müllerian hormone (AMH) have been shown to be reliable markers of ovarian reserve. This study aimed to compare baseline serum AMH levels and well-controlled clinical factors between patients with unilateral and bilateral ovarian endometriomas during the menstrual phase.

METHODS

We conducted a retrospective study. We enrolled 136 patients aged 18 to 36 years who were diagnosed with unilateral or bilateral ovarian endometriomas. Serum AMH levels of all patients and their latest two to three menstrual cycles were measured before surgery for ovarian endometriomas. The latest menstrual cycle length ranged from 26 to 30 days. Patients with irregular menstruation, a recent medication history of hormonal drugs other than oral contraceptive pills, a previous history of ovarian surgery, or any medical history influencing ovarian function were excluded.

RESULTS

Of the 136 patients, 76 (55.9%) had unilateral ovarian endometriomas and 60 (44.1%) had bilateral ovarian endometriomas. Serum AMH levels were not significantly different between the two groups in the follicular phase, luteal phase, or at any random time point.

CONCLUSION

Serum AMH levels were not significantly different between unilateral and bilateral ovarian endometriomas in the follicular and luteal phases, or at any random time during the menstrual cycle when various confounding factors were excluded.

Iron deposition in ovarian endometriosis evaluated by magnetic resonance imaging R2* correlates with ovarian function

RESEARCH QUESTION

Does iron overload in patients with endometriosis affect ovarian function? Can a method be developed to visually reflect this?

DESIGN

Magnetic resonance imaging (MRI) R2* was used to evaluate the correlation between iron deposition of ovarian and anti-Müllerian hormone (AMH) in patients with endometriosis. All patients underwent T2* MRI scanning. Serum AMH levels were measured preoperatively. The area of focal iron deposition, iron content of the cystic fluid and AMH levels between the endometriosis and control groups were compared using non-parametric tests. The effects of iron overload on AMH secretion in mouse ovarian granulosa cells were investigated by adding different concentrations of ferric citrate to the medium.

RESULTS

A significant difference was found between endometriosis and control groups in area of iron deposition (P < 0.0001), cystic fluid iron content (P < 0.0001), R2* of lesions (P < 0.0001) and R2* of the cystic fluid (P < 0.0001). Negative correlations were found between serum AMH levels and R2* of cystic lesions in patients with endometriosis aged 18-35 years (rs = -0.6484, P < 0.0001), and between serum AMH levels and R2* of cystic fluid (rs = -0.5074, P = 0.0050). Transcription level (P < 0.0005) and secretion level (P < 0.005) of AMH significantly decreased with the increase in iron exposure.

CONCLUSION

Iron deposits can impair ovarian function, which is reflected in MRI R2*. Serum AMH levels and R2* of cystic lesions or fluid in patients aged 18-35 years had a negative correlation with endometriosis. R2* can be used to reflect the changes of ovarian function caused by iron deposition.

Mismatch repair protein deficiency in endometriosis: Precursor of endometriosis-associated ovarian cancer in women with lynch syndrome

OBJECTIVE

We aimed to elucidate the pathogenesis of ovarian cancer through the loss of mismatch repair (MMR) proteins in women with Lynch syndrome (LS) in this report.

CASE REPORT

Two women with LS underwent surgery for synchronous endometrial cancer and ovarian cancer. In both cases, immunohistochemical examination showed concomitant MMR protein deficiency in endometrial cancer, ovarian cancer, and contiguous ovarian endometriosis. In Case 1, the macroscopically normal ovary included multiple endometrioses with MSH2 and MSH6 expression, and FIGO grade 1 endometrioid carcinoma and contiguous endometriosis without MSH2 and MSH6 expression. In Case 2, all endometriotic cells contiguous with carcinoma in the lumen of the ovarian cyst showed loss of the expression of MSH2 and MSH6.

CONCLUSION

Ovarian endometriosis with MMR protein deficiency may progress to endometriosis-associated ovarian cancer in women with LS. Diagnosing endometriosis in women with LS during surveillance is important.

JARID2 regulates epithelial mesenchymal transition through the PTEN/AKT signalling pathways in ovarian endometriosis

Recently, it has been proposed that epithelial-mesenchymal transition (EMT) plays a key role in the development of endometriosis (EMs). Although EMs is a benign disease, it has the characteristics of malignant tumors, such as invasion and migration. JARID2 (Jumonji, AT rich interaction domain) can induce EMT in cancer cells to increase their invasion and migration abilities. However, whether JARID2 has the same function in EMs is not yet known. In this study, A retrospective immunohistochemistry(IHC) was used to measure the expression of JARID2, E-cadherin, PTEN, and p-AKT in ovarian endometriosis (OE) tissues. JARID2, EMT and PTEN/AKT signaling pathway related indicators were assessed by RT-PCR and western blotting in vitro. Furthermore, functional assays were applied to evaluate the involvement of JARID2 in the invasion and migration of Ishikawa cells. Here,we conclude that JARID2 could be involved in the PTEN/AKT signalling pathway and contribute to the development of ovarian endometriosis. The expression of JARID2 was negatively correlated with PTEN, but positively correlated with p-AKT in the ectopic endometrial tissues of OE cases. JARID2 overexpression increased the expression of N-cadherin, vimentin and AKT, but inhibited the expression of E-cadherin and PTEN. Accordingly, the opposite results were obtainedwhen JARID2 was downregulated. Furthermore, JARID2 promoted the invasion and migration ability of Ishikawa cells.

True Prevalence of Diaphragmatic Endometriosis and Its Association with Severe Endometriosis: A Call for Awareness and Investigation

STUDY OBJECTIVE

To identify characteristics indicating preoperatively the presence of diaphragmatic endometriosis (DE).

DESIGN

Comparison of characteristics of patients with diaphragmatic endometriosis (DE) with characteristics of patients with abdominal endometriosis without diaphragmatic involvement, in a prospective cohort study.

SETTING

Tertiary referral center; endometriosis center.

PATIENTS

A total of 1372 patients with histologically proven endometriosis.

INTERVENTIONS

Surgery performed laparoscopically under general anesthesia. All patients with suspected endometriosis underwent a complete bilateral inspection of the diaphragm.

MEASUREMENTS AND MAIN RESULTS

Demographic and clinical pathologic characteristics were evaluated using basic descriptive statistics (comparison of the groups using the χ2 test and the Mann-Whitney t test). A logistic regression analysis was performed to evaluate the relationship (hazard ratio) between symptoms and the presence of DE. DE was diagnosed in 4.7% of the patients (65 of 1372). There was no significant difference between the 2 groups (patients with abdominal endometriosis with or without DE) with regard to typical endometriosis pain (dysmenorrhea, dyschezia, dysuria, and/or dyspareunia). However, in the DE group, diaphragmatic pain was present significantly more often preoperatively (27.7% vs 1.8%, p <.001). Four DE patients (6.1 %) were asymptomatic (with infertility the indication for surgery). In the DE group, 78.4 % had advanced stages of endometriosis (revised American Fertility Society III° or IV°); the left lower pelvis was affected in more patients (73.8%). In cases of ovarian endometriosis, patients with DE showed a significantly higher prevalence of left ovaries involvement (left 63% vs right 35.7%, p <.001). Patients with DE had a significantly higher rate of infertility (49.2% vs 28.7%, p <.05).

CONCLUSION

Patients with shoulder pain, infertility, and/or endometriosis in the left pelvis have a significant higher risk of DE and therefore need specific preoperative counseling and if indicated surgical treatment.

IGF2BP2 promotes the progression of ovarian endometriosis by regulating m6A-modified MEIS2 and GATA6

BACKGROUND

m6A-RNA modification mediated by the N6-methyladenosine RNA methylation-related molecule methyltransferase-like 3 has been implicated in the progression of endometriosis. However, the functions of other m6A regulators, especially in ovarian endometriosis, remain unknown.

METHODS

Three datasets (GSE7305, GSE7307, and GSE37837) with diagnosed ovarian endometriosis were extracted from the Gene Expression Omnibus database. Using bioinformatics methods such as Weighted Gene Co-expression Network Analysis, Gene Ontology analysis, protein-protein interaction, and correlation, hub genes were identified. Using dot blot and N6-methyladenosine-IP-qPCR, the total and individual N6-methyladenosine gene levels were quantified. On clinical ovarian ectopic and eutopic endometrium tissues, N6-methyladenosine RNA methylation sequencing was performed. To authenticate protein localization and expression level, immunohistochemical staining and western blot were conducted, respectively. The database Connectivity Map was used to predict small molecules with potential therapeutic effects.

RESULTS

In ovarian endometriosis, the N6-methyladenosine "reader" molecule IGF2BP2 and related target genes MEIS2 and GATA6 were highly expressed. IGF2BP2 promoted the proliferation, migration, and invasion of ectopic endometrial stromal cells by stabilizing the mRNA of MEIS2 and GATA6. Synergistically, METTL3 and IGF2BP2 increased the N6-methyladenosine methylation of MEIS2 and GATA6. We developed five molecules (Mercaptopurine, MK-886, CP-863187, Canadine, and Securinine) that could be used to treat ovarian endometriosis based on IGF2BP2.

CONCLUSION

Our findings provided additional support for a systematized understanding of the role of N6-methyladenosine RNA methylation in endometriosis and confirmed for the first time the mechanism of IGF2BP2 in promoting ovarian endometriosis. This provides the molecular foundation for potential future therapies for ovarian endometriosis.

DATA AVAILABILITY

The data used to support the findings of this study are available from the corresponding author upon request.

Potential clinical implications of iron metabolism in ovarian endometriosis

OBJECTIVE

The purpose of this study was to investigate iron metabolism indices in ovarian endometriosis (OEMs) and to demonstrate the potential clinical implications in the initiation and development of OEMs.

METHODS

Three datasets in Gene Expression Omnibus (GEO) database were selected to assess the expression levels of iron metabolites in endometrial tissues from patients with EMs and the health. To evaluate the differential expression of serum iron indices , hospitalized patients with OEMs and health examinees in Jilin University Second Hospital from November 2018 to December 2019 were recruited. Serum samples were obtained from 38 patients with OEMs and 36 health examinees. To compare the iron metabolism between peripheral circulation blood and local ectopic lesion, cyst fluid samples were obtained from 15 patients with ovarian chocolate cyst at the time of surgery. Iron metabolism indices include iron, transferrin (TF), ferritin, and unsaturated iron-binding capacity (UIBC)), which were measured by automatic biochemical analyzer.

RESULTS

The present study indicated the increased levels of the iron storage protein, ferritin, in the endometriotic tissues of patients with EMs. The expression of iron and ferritin in cyst fluid of patients with OEMs showed higher than that in serum, the results of TF and UIBC were opposite (P < 0.05). There was no statistical difference in the content of iron metabolites between patients with OEMs and the healthy examinees(P > 0.05).

CONCLUSION

The ovarian chocolate cyst fluid and endometriotic tissues in patients with OEMs could more directly reflect the pathological changes of local ectopic lesion, which usually manifested as high levels of free iron and/or iron deposits in the ectopic sites. The implications of our work suggest iron metabolites in the serum may have potentially limited value as circulating biomarkers for OEMs. The iron variation in local lesions may be not only regulated by liver that mainly manipulate the systematic iron homeostasis, but also be tuned by the iron regulatory protein (IRP)/ iron responsive element (IRE) system. In summary, the iron metabolites, especially the iron and ferritin in the cyst fluid and endometriotic tissues, are meaningful biomarkers involved in the process of pathophysiology and pathogenesis of OEMs.

The presence of living endometrial cells in ovarian endometriotic cyst fluid may contribute to the recurrence of endometriosis after surgical excision of endometriomas

BACKGROUND

Many factors can affect the recurrence of endometriosis after surgery, however, whether endometriotic cyst fluid contributes to endometriosis recurrence after surgical excision of ovarian endometriomas remains unclear. The objective of this study was to determine the presence of endometrial cells in ovarian endometriosis cyst fluid and the potential differences between these cells and those in the cyst wall.

METHODS

Samples of cyst fluid (n = 39) and drainage fluid (n = 14) were collected from patients with ovarian endometriomas undergoing laparoscopic surgery. Drainage fluid from 14 patients without endometriosis was used as a control. The presence of endometrial cells in cyst fluid and drainage fluid was determined by cell culture in vitro and immunostaining. In addition, cyst fluid endometrial fragments and viscosity were analysed by transcriptome sequencing analysis and apparent diffusion coefficients, respectively. An animal model was used to confirm the ability of endometrial cells in cyst fluid to form new lesions.

RESULTS

We found endometrium-like tissues in 71.8% (28/39) of cyst fluid and 71.4% (10/14) of drainage fluid samples by histopathological examination, and the presence of endometrioid tissue in cyst fluid was related to the viscosity of the cyst fluid. The living endometrial cells in cyst fluid and drainage fluid were confirmed by cell culture in vitro and immunostaining. Moreover, the adhesion ability of endometrial fragments in cyst fluid was significantly higher than that of ectopic tissues in the cyst wall (P < 0.05). In addition, living endometrial cells in the cyst fluid were able to adhere and alive in the animal model.

CONCLUSIONS

The existence of living endometrial cells with high adhesion ability in ovarian endometriotic cyst fluid may contribute to the recurrence of endometriosis after surgical excision of endometriomas due to cyst fluid outflow during the surgical procedure.

Identification of Key Differentially Methylated/Expressed Genes and Pathways for Ovarian Endometriosis by Bioinformatics Analysis

The goal of this study was to identify genes that were differentially methylated and differentially expressed and their related signaling pathways in ovarian endometriosis tissue. First, the DNA methylation and gene expression profiles in the endometrial tissue of patients with ovarian endometriosis were studied using Illumina 450K methylation microarray analysis and the GSE141549 gene expression dataset. Second, differentially methylated and differentially expressed genes, herein referred to as differentially methylated/expressed genes, were identified and protein-protein interaction networks and functional analysis of these genes were determined. Third, qPCR and immunohistochemistry of patient samples was used to confirm the differential expression of a subset of differentially methylated/expressed genes. Finally, the GSE7305 dataset was used confirm the expression profile of differentially methylated/expressed genes and to determine the potential usefulness of these genes for diagnosis of endometriosis. A total of 37 hypermethylated low-expression genes and 66 hypomethylated high-expression genes were identified in ovarian endometriosis patients. Protein-protein interaction and functional analysis highlighted 8 hypermethylated low-expression genes (KRT19, KRT8, ESR1, PRL, SFN, IL20RA, IL2RB, and PAX8) and 4 hypomethylated high-expression genes (CYP11A1, NR5A1, ME1, and GSTM1). Significantly, both of these gene sets had a diagnostic value for patients with ovarian endometriosis. Signaling pathways that were identified included JAK-STAT (involving IL20RA and IL2RB), prolactin (involving PRL and ESR1), Staphylococcus aureus infection (involving KRT19), viral protein interaction with cytokine and cytokine receptor (involving IL20RA and IL2RB), cytokine-cytokine receptor interaction (involving IL20RA and IL2RB), and drug metabolism-cytochrome P450 (involving GSTM1). The differentially methylated/expressed genes and enriched signaling pathways identified in this study are likely to be associated with the process of ovarian endometriosis.

The High Expression of RRM2 Can Predict the Malignant Transformation of Endometriosis

INTRODUCTION

A large number of epidemiological studies have revealed that women with endometriosis (EMS) have a higher risk of developing endometriosis-associated ovarian cancer (EAOC). At present, there are few studies on predicting the malignant transformation of ovarian endometriosis (OE). The purpose of this study is to identify and verify the molecules that may be able to predict the malignant transformation of OE.

METHODS

The gene expression profiles of ovarian cancer and OE were downloaded from Gene Expression Omnibus (GEO), and a common hub gene ribonucleotide reductase M2 (RRM2) was identified. A total of 44 patients with EAOC and 44 with OE were enrolled in this study. Immunohistochemistry (IHC) and quantitative reverse transcription polymerase chain reaction (RT-qPCR) were used to detect the expression of RRM2, while the relationship between RRM2 and Ki-67 was analyzed by IHC co-localization.

RESULTS

Bioinformatics analysis showed that the expression of RRM2 was low in EMS and high in ovarian cancer. RRM2 was obviously positively expressed in eutopic endometrium (EU), ectopic endometrium (EC), and cancer tissues of EAOC patients. The IHC signal and mRNA levels of RRM2 were higher in the EC of EAOC patients compared with OE patients (P < 0.01). In addition, there was a correlation between the expression of RRM2 and Ki-67 in EC of EAOC patients (P < 0.01).

CONCLUSION

The upregulated expression of RRM2 in the EC of OE patients may indicate malignant transformation. High expression of RRM2 promotes abnormal proliferation of histiocytes. RRM2 can be used as a potential marker of malignant transformation of OE.

Frequent DYSF rare variants/mutations in 152 Han Chinese samples with ovarian endometriosis

PURPOSE

Endometriosis is a common chronic gynecological disease greatly affecting women health. Prior studies have implicated that dysferlin (DYSF) aberration might be involved in the pathogenesis of ovarian endometriosis. In the present study, we explore the potential presence of DYSF mutations in a total of 152 Han Chinese samples with ovarian endometriosis.

METHODS

We analyze the potential presence of DYSF mutations by direct DNA sequencing.

RESULTS

A total of seven rare variants/mutations in the DYSF gene in 10 out of 152 samples (6.6%) were identified, including 5 rare variants and 2 novel mutations. For the 5 rare variants, p.R334W and p.G941S existed in 2 samples, p.R865W, p.R1173H and p.G1531S existed in single sample, respectively; for the two novel mutations, p.W352* and p.I1642F, they were identified in three patients. These rare variants/mutations were absent or existed at extremely low frequency either in our 1006 local control women without endometriosis, or in the China Metabolic Analytics Project (ChinaMAP) and Genome Aggregation Database (gnomAD) databases. Evolutionary conservation analysis results suggested that all of these rare variants/mutations were evolutionarily conserved among 11 vertebrate species from Human to Fox. Furthermore, in silico analysis results suggested these rare variants/mutations were disease-causing. Nevertheless, we find no significant association between DYSF rare variants/mutations and the clinical features in our patients. To our knowledge, this is the first report revealing frequent DYSF mutations in ovarian endometriosis.

CONCLUSION

We identified a high frequency of DYSF rare variants/mutations in ovarian endometriosis for the first time. This study suggests a new correlation between DYSF rare variants/mutations and ovarian endometriosis, implicating DYSF rare variants/mutations might be positively involved in the pathogenesis of ovarian endometriosis.

Target identification and drug discovery by data-driven hypothesis and experimental validation in ovarian endometriosis

OBJECTIVE

To identify targets and discover drugs for ovarian endometriosis (OE) DESIGN: A basic study based on a data-driven hypothesis and experimental validation SETTING: Center for Reproductive Medicine PATIENT(S)/ANIMAL(S): Fourteen patients with OE and 7 healthy donors were recruited, and 15 female C57/BL6 mice were involved.

INTERVENTION(S)

Samples of OE lesions and normal endometrium were obtained. The ITPR1-knockdowned ectopic human endometrial stromal cells (HESCs) were subjected to ribonucleic acid (RNA) sequencing, cell-counting kit-8 (CCK-8) assay, 5-ethynyl-2'-deoxyuridine (EdU) staining, and flow cytometry. Camptothecin was administered to HESCs and in an OE mouse model.

MAIN OUTCOME MEASURE(S)

ITPR1 expression in OE lesions and normal endometrium, cell proliferation and apoptosis of HESCs with ITPR1 knockdown or camptothecin treatment, and autograft volume in the OE mouse model RESULT(S): Two significant OE-relevant gene modules were identified and involved the PI3K/Akt and aging-relevant pathways. Fifteen hub genes were identified and confirmed, among which the most significant gene, ITPR1, was robustly elevated in OE lesions. RNA sequencing revealed that ITPR1 was highly relevant to cell proliferation and apoptosis, which was further confirmed by CCK-8 assay, EdU staining, and flow cytometry analysis. ITPR1 knockdown inhibited cell proliferation and induced HESC apoptosis. The candidate drugs targeting these modules were screened, among which camptothecin and irinotecan were identified as promising drugs. Both compounds suppressed HESC proliferation and induced apoptosis; ITPR1 expression was suppressed by camptothecin. The therapeutic effect of camptothecin was also validated in the OE mouse model.

CONCLUSION(S)

This study identified the therapeutic targets and promising drugs for OE and shed light on the use of camptothecin in OE treatment.

Effects of CDKN2B-AS1 on cellular proliferation, invasion and AKT3 expression are attenuated by miR-424-5p in a model of ovarian endometriosis

RESEARCH QUESTION

Endometriosis is a common and complicated gynaecologic disease. Long non-coding RNA CDKN2B-AS1 plays a crucial role in the development and progression of several cancers. Whether CDKN2B-AS1 contributes to endometriosis, however, remains unknown.

DESIGN

Cellular proliferation, invasion and DNA synthesis abilities were assessed by CCK8, transwell and 5-ethynyle-2'-deoxyuridine assays. The expression of epithelial-mesenchymal transition markers and three isoforms of AKT was detected using Western blot. Real-time polymerase chain reaction was used to determine the relative expression levels of CDKN2B-AS1 and candidate miRNAs in ectopic, eutopic endometria and normal endometrial tissues. The relationship between CDKN2B-AS1 and miRNA was determined by luciferase reporter assays.

RESULTS

The relative expression level of CDKN2B-AS1 was up-regulated in eutopic and ectopic endometria. In endometrial stromal cells and Ishikawa cells, CDKN2B-AS1 overexpression promoted cellular proliferation and invasion, and increased the protein expression of vimentin but decreased the expression of E-cadherin. miR-424-5p was confirmed the target of CDKN2B-AS1 through bioinformatics tools and luciferase reporter assays. In addition, the enhanced effect of cellular phenotype of CDKN2B-AS1 overexpression was significantly attenuated by miR-424-5p overexpression. Furthermore, miR-424-5p was able to directly target AKT3 through luciferase reporter assay. Mechanistically, CDKN2B-AS1 acts as a ceRNA by sponging miR-424-5p and targets AKT3.

CONCLUSIONS

The cellular mechanism of CDKN2B-AS1 in endometriosis was confirmed; CDKN2B-AS1 may be a potential target for ovarian endometriosis therapy.

Differential expression of Lumican, Mimecan, Annexin A5 and Serotransferrin in ectopic and matched eutopic endometrium in ovarian endometriosis: a case-control study

AIM

Endometriosis is a debilitating disease marked by recurrent gynecological proliferations. The present study aimed at performing differential proteomic analysis of matched eutopic and ectopic endometrium from women with ovarian endometriosis.

MATERIALS AND METHODS

Proteomes were resolved using nano LC-MS and further identified and quantified using ProteinLynx Global SERVER (PLGS) software. Selected proteins were further chosen for validation by real time-polymerase chain reaction (RT-PCR).

RESULTS

The protein profiles uncovered several differentially expressed proteins in the diseased sample (ectopic endometrium) as compared to the reference sample (eutopic endometrium). The study involved an advanced proteomic approach, nano LC-MS, and validates for the first time the upregulation of Mimecan and Lumican proteins in endometriosis.

CONCLUSIONS

These proteins may hence prove as potentially useful tools in the search for diagnostic markers for early detection of the disease.

Preventive therapeutic options for postoperative recurrence of ovarian endometrioma: gonadotropin-releasing hormone agonist with or without levonorgestrel intrauterine system insertion

PURPOSE

Here, we compared endometrioma recurrence rates in patients who have undergone a laparoscopic cystectomy and treated with a gonadotropin-releasing hormone agonist (GnRHa) alone or a GnRHa combined with a levonogestrel intrauterine system (LND-IUS).

METHODS

We enrolled endometrioma patients who underwent laparoscopic cyst enucleation and divided them into two groups according to postoperative management: GnRHa alone and GnRHa in combination with LND-IUS. We compared preoperative history, perioperative parameters, postoperative endometrioma recurrence, and symptoms between these two groups.

RESULTS

A total of 320 patients were included in the final analysis. With a median 84.6 months of follow-up, we detected significant differences between the two groups with respect to age at surgery (31.6 ± 4.8 vs. 37.6 ± 4.2 years, χ² = 1.978, p < 0.001), gravida (0 vs. 2, χ² = 4.391, p < 0.001), parity (0 vs. 1, χ² = 0.035, p < 0.001), body mass index (21.0 ± 2.5 vs. 21.9 ± 2.4, χ² = 0.0096, p = 0.009), r-AFS score (48 vs. 64, χ² = 4.888, p = 0.001), and operation time (60 vs. 75 min, χ² = 9.119, p = 0.003). Patients treated with both GnRHa and LND-IUS achieved significantly less endometrioma recurrence (23.6 vs. 11.5%, χ² = 5.202, p = 0.023) and higher rates of pain remission (92.1 vs. 100%, χ² = 6.511, p = 0.011), while those with GnRHa alone suffered more recurrent and painful symptoms (χ² = 9.280, p = 0.026). Multivariate analysis using a Cox regression demonstrated that combined GnRHa and LNG-IUS treatment correlated with a decreased endometrioma recurrence rate after laparoscopic cystectomy (RR 0.369, 95% CI 0.182-0.749, p = 0.006).

CONCLUSIONS

Combination treatment of GnRHa and LNG-IUS exhibited superior pain relief and recurrence prevention among endometrioma patients after fertility-sparing surgery. Thus, combination treatment is a preferable long-term option for patients without intent for pregnancy in the near future.

Novel ovarian endometriosis model causes infertility via iron-mediated oxidative stress in mice

Ovarian endometriosis (OE) provides women of reproductive age with not only severe menstrual pain but also infertility and an increased risk for ovarian carcinogenesis. Whereas peritoneal endometriosis models have been developed with syngeneic implantation of minced uterine tissue and oncogenic K-ras allele with conditional Pten deletion within ovarian surface epithelium generated preneoplastic endometrial glandular morphology, followed by endometrioid adenocarcinoma, there has been no mouse model of OE similar to human counterparts, applicable to preclinical studies. Here we for the first time established a murine OE model that reveals infertility, and evaluated the involvement of iron catalyzed oxidative stress in the pathogenesis. Minced uterine tissue from female mice was implanted on ovarian surface of syngeneic mice after bursectomy to induce OE. Ectopic growth of endometrium was observed in association with ovary 4 weeks after implantation in 85.7% (12/14) of the operated mice with our protocol. Endometriotic lesions involved intestine, pancreas and peritoneal wall. Fibrosis around the ovary was prominent and increased time-dependently in the OE group. Iron accumulation was significantly increased in the OE group, leading to oxidative stress in each stage of the follicles as evaluated by 4-hydroxy-2-nonenal-modified proteins and 8-hydroxy-2′-deoxyguanosine. Expression of follicle stimulating hormone receptor in the follicles revealed a significant decrease during pre-antral, antral and pre-ovulatory phases in the OE group. Finally, the number of pups was significantly reduced in the OE group in comparison to the controls. This model affords an opportunity to evaluate agents or procedures to counteract ovarian endometriosis in the preclinical settings.

•

We for the first time established a murine ovarian endometriosis model via bursectomy.

•

Ovarian endometriosis induced iron catalyzed oxidative stress in ovarian follicles.

•

This ovarian endometriosis model reveals infertility and is applicable to preclinical studies.

An integration analysis of mRNAs and miRNAs microarray data to identify key regulators for ovarian endometriosis based on competing endogenous RNAs

This study aimed to uncover effects of non-coding RNA transcripts on ovarian endometriosis (OEM) development. Two transcription datasets (GSE105764 and GSE105765) about OME were downloaded from Gene Expression Omnibus (GEO) database and the differentially expressed mRNAs, lncRNAs and miRNAs (DEmRNAs, DElncRNAs and DEmiRNAs) between OEM cases and controls were identified followed by protein-protein interaction analysis. Then, co-expression analysis was conducted and DEmiRNAs-DEmRNAs as well as DElncRNAs-DEmiRNAs pairs were predicted to construct the ceRNA network followed by sub-ceRNA network associated with OEM extraction. Functional analyses of DEmRNAs in ceRNA and sub-module network and the survival analysis were also performed to evaluate the correlation of key regulators and OV outcomes. Totally, 1910 DEmRNAs, 158 DElncRNAs and 118 DEmiRNAs were screened between OEM cases and controls and the functional analyses of DEmRNAs showed that they were significantly enriched in cell adhesion. Furthermore, there were 505 nodes in PPI network and ceRNA network included 762 interaction pairs among 357 DEmRNAs, 28 DElncRNAs and 24 DEmiRNAs. The KEGG analysis suggested several genes including FOXO1, STAT5A and RUNX1 were predominately associated with pathways in cancer while IL15 was primarily enriched in cytokine-cytokine receptor interaction pathway. Importantly, these two pathways were also found to be implicated with OEM development. Finally, survival analysis implied that overexpression of ZFPM2-AS1 had a good clinical outcome while the under-expression levels of FOXO1, JUP, STAT5A, RUNX1 and PRKG1-AS1 exhibited a better prognosis for OV. FOXO1, STAT5A, RUNX1 and IL15, PRKG1-AS1 and ZFPM2-AS1 were promising diagnostic makers for OME.

A novel non-invasive molecular biomarker in ovarian endometriosis: estrogen-related receptor α

PURPOSE

This study aimed to explore whether estrogen-related receptors α (ERRα) can prognosticate the occurrence and development of ovarian endometriosis (EMs) as a non-invasive biomarker.

METHODS

The ectopic and its' correspond eutopic endometria from 47 patients with ovarian EMs and the control normal endometria from 32 cases were collected and detected the mRNA expression of ERRα by RT-qPCR. The serum protein of ERRα were tested by ELISA. The menstrual cycle, ovarian cyst sizes, relative clinical tumour markers, such as CA125, CA19-9 and HE-4, and other demographic data were also involved into analysis in these patients by SPSS 22.0 (IBM, Chicago, IL, USA).

RESULTS

The ERRα mRNA expression in ectopic endometria were significantly lower than it in eutopic endometria (P < 0.05) and the normal endometria (P < 0.05). Similarly, the serum ERRα levels in patients with EMs were significantly lower than it in control group (P < 0.01). Moreover, the serum ERRα levels were decreasing with the increasing of the pathological stages and ovarian cyst sizes. While, the serum CA125, CA19-9, CA125/ERRα ratio and CA19-9/ERRα ratio in the study group were significantly higher than those in the control group (all P < 0.01).

CONCLUSION

The expression of ERRα is correlated with the development of ovarian EMs pathological stages and ovarian cyst sizes and can be used as a novel and non-invasive biomarker for evaluating the progression of ovarian EMs.

Fertility Outcome after CO2 Laser Vaporization versus Cystectomy in Women with Ovarian Endometrioma: A Comparative Study

STUDY OBJECTIVE

To assess the postoperative likelihood of conception in patients with endometriomas managed by either CO₂ laser vaporization or cystectomy.

DESIGN

A retrospective study with prospective recording of data.

SETTING

University hospital.

PATIENTS

One hundred and forty-two patients with symptomatic endometriomas.

INTERVENTIONS

Patients underwent a standardized laparoscopic stripping technique (Group 1) or cyst vaporization with CO₂ fiber laser (Group 2). Patients wishing to become pregnant were allowed to attempt a spontaneous conception after surgery. If spontaneous conception failed, patients were referred for in vitro fertilization (IVF).

MEASUREMENTS AND MAIN RESULTS

The primary objective was to compare pregnancy rates between the 2 groups. The secondary objective was the identification of independent predictors of pregnancy. Thirty-nine women in Group 1 (53.4%) and 39 women in Group 2 (56.5%) desired to conceive after surgery. Three patients (7.7%) in Group 1 became pregnant following donor-IVF and were excluded. Pregnancies were recorded in 72.2% of patients treated with cystectomy and in 74.3% of those managed with CO₂ fiber laser (p = .83). Twenty patients (55.6%) in Group 1 and 14 patients (35.9%) in Group 2 conceived spontaneously (p = .08). Among patients who failed spontaneous conception, 21 patients (28%) achieved pregnancy through IVF (Group 1: n = 6, 16.7%; Group 2: n = 15, 38.5%; p = .08). Twenty patients (26.7%) never became pregnant. Age at the time of surgery (odds ratio (OR) = 0.86; 95% Confidence intervals (CI): 0.78-0.96, p = .002) and duration of infertility (OR=0.80; 95% CI: 0.69-0.92, p = .006) were identified as independent indicators for pregnancy.

CONCLUSION

CO₂ laser-treated endometrioma is associated with pregnancy rates equal to those observed after cystectomy and favorable IVF outcomes. The one step CO₂ fiber laser technique may represent a viable alternative to cystectomy.

Identification of MicroRNAs as Potential Biomarkers in Ovarian Endometriosis

Endometriosis, as a prevalent gynecological disease, is characterized by the presence of endometrial-like tissue outside the uterus, causing infertility and considerable pain and affecting the quality of life of women. The pathogenic mechanism has not been fully elucidated, and there are no effective biomarkers for endometriosis. In our study, microRNA (miRNA) expression profiling of 10 ectopic endometrial plasma from patients with ovarian endometriosis and 10 normal plasma from healthy controls was analyzed using a microarray. As a result, 114 differentially expressed miRNAs were identified. Among them, 14 miRNAs were significantly downregulated in patients with ovarian endometriosis, which matched the microarray results. The diagnostic value of the 14 downregulated miRNAs in ovarian endometriosis was evaluated by receiver operating characteristic (ROC) curve analysis, and hsa-let-7i-5p showed the highest area under the ROC curve (AUC) with a value of 0.900. The target genes of the 14 miRNAs were predicted by miRWalk2.0, and the genes that were targeted by at least 2 of the 14 miRNAs were analyzed by function enrichment. The target genes were significantly enriched in the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, such as microRNAs in cancer, bladder cancer, and endocrine resistance pathways, and the Gene Ontology (GO) terms such as nucleobase-containing compound metabolic process, cellular nitrogen compound biosynthetic process, and heterocycle metabolic process. The identified 14 differentially expressed miRNAs could be potential biomarkers and therapeutic targets for the diagnosis and treatment of endometriosis.

Clinical characteristics difference between early and late recurrence of ovarian endometriosis after laparoscopic cystectomy

BACKGROUND

Ovarian endometriosis is the most frequent type of endometriosis. Despite the use of surgery and medication, many patients suffer from recurrence within near future. Currently, there are no effective clinical characteristics available to predict the time to recurrence in ovarian endometriosis patients.

PURPOSE

To identify the effective clinical indicators for early and late endometrioma recurrence, we compared the clinical characteristics of early and late recurrence after treatment.

METHODS

We collected 358 patients with ovarian endometriosis who had a minimum of 5 years of postoperative follow-up after undergoing a laparoscopic excision of ovarian endometrioma performed at Peking Union Medical College Hospital from January 2009 to April 2013.

RESULTS

A total of 358 patients were recruited in the validation set, with a median follow-up time of 83 months (60-120 months). Till the last follow-up, 68 patients exhibited recurrence. Three-year and 5-year recurrence rates were 9.2% and 15.4%, respectively. Univariate analysis in our study showed that patient with endometrioma surgery history had higher incidence of recurrence in 3 years after re-surgery (OR: 5.594, P = 0.029). Univariate and multivariate analyses using the logistic regression showed that the presence of tenesmus before surgery affected the incidence of early recurrence with a ratio of 57.9% (11/19) and 89.5% (17/19) in 3 years and 5 years after surgery, respectively.

CONCLUSIONS

Presence of tenesmus before surgery may be linked to the early recurrence of endometrioma.

Ezrin T567 phosphorylation regulates migration and invasion of ectopic endometrial stromal cells by changing actin cytoskeleton

AIMS

The enhanced ability of endometrial cell migration and invasion is the foundation for formation of ectopic lesions in endometriosis. Ezrin has been reported to regulate cell motility by remodeling the cytoskeleton. However, little is known about the mechanisms through which ezrin remodels the cytoskeleton and cell structure to promote cell motility in endometriosis.

METHODS

In our study, expression and distribution of ezrin, and Rho pathway were detected through immunohistochemical analysis. The effects of inhibiting ezrin T567 phosphorylation on Rho signaling pathway and cytoskeleton were investigated through western blot, transmission electron microscopy and immunofluorescence analysis.

KEY FINDINGS

We found that the expression of ezrin and Rho pathway was higher in ectopic endometrium. NSC305787 inhibited the phosphorylation of ezrin T567, resulting in decreased expression of Rho pathway and reduced filopodia formation in ectopic endometrial stromal cells.

SIGNIFICANCE

Taken together, our study suggested that ezrin T567 phosphorylation modulated migration and invasion of ectopic ESCs through actin reconstructions, which may serve as a novel therapeutic target in ovarian endometriosis.

Fertility Outcomes After Laparoscopic Cystectomy in Infertile Patients with Stage III-IV Endometriosis: a Cohort with 6-10 years of Follow-up

INTRODUCTION

Ovarian endometriosis is the most common type of endometriosis (EM), affecting more than 40% of women with EM. Currently, surgical intervention is still controversial in infertile patients with ovarian endometriosis, especially in those with stage III-IV EM. Very few studies have been done to analyze long-term pregnancy results in patients with endometrioma more than 5 years after surgery. Therefore, the aim of this study was to explore the pregnancy outcomes and the related factors in patients with endometrioma and stage III-IV endometriosis during a long-term follow-up postoperatively.

METHODS

We collected 347 patients with ovarian endometriosis, which included 59 infertile patients with stage III-IV endometriosis who had a minimum of 5 years of postoperative follow-up after undergoing laparoscopic excision of ovarian endometriomas performed by a single doctor at the Peking Union Medical College Hospital from January 2009 to April 2013.

RESULTS

A total of 59 infertile patients were recruited. The mean age was 31.8 ± 3.6 years. The mean size of the endometriomas was 6.8 ± 3.3 cm. Before surgery, dysmenorrhea was present in 88.1% (52/59) of the cases, while chronic pelvic pain was reported in nine cases (15.3%). A total of 20.3% (12/59) of cases were concurrent with leiomyoma, 52.5% (31/59) with deep infiltrating endometriosis (DIE), and 39.0% (23/59) with adenomyosis. During laparoscopy, 21 cases were diagnosed as stage III (35.6%) and 38 as stage IV (64.4%) EM according to the revised American Fertility Society (AFS) classification. After laparoscopic cystectomy, 38 (64.4%) patients became successfully pregnant by the 5th year. All the patients were divided into two groups according to the postoperative pregnancy outcomes. In univariate analysis, the higher mean age and concurrent diagnosis of adenomyosis were seen to be related to poor postoperative pregnancy outcomes (p < 0.05). In multivariate analysis, however, the mean age, chronic pelvic pain (CPP), and adenomyosis were independent risk factors of pregnancy outcomes between the two groups (p < 0.05). With a minimum follow-up of 6 years, 23.7% (14/59) of recurrence was observed in the entire study cohort.

CONCLUSION

Infertile patients with endometrioma and stage III-IV EM may have lower pregnancy rates after laparoscopic cystectomy if they are older and present with CPP and adenomyosis. Our data showed a lower rate of recurrence but a higher rate of pregnancy after surgery.

Comparative analysis of abdominal fluid cytokine levels in ovarian hyperstimulation syndrome (OHSS)

BACKGROUND

Ovarian hyperstimulation syndrome (OHSS) is a rare, yet severe, iatrogenic complication of ovulation induction therapy during assisted reproductive procedures. Our group previously detected atypical cells in the ascitic fluid of OHSS patients, although no malignancy developed during follow up. Here, the aim was to perform a comparative analysis of the cytokines present in the abdominal fluid of patients affected by OHSS versus patients with advanced ovarian cancer, a benign adnexal mass, or ovarian endometriosis.

METHODS

This prospective, non-randomized study was conducted at the Clinical Center of the University of Pecs Department of Obstetrics and Gynecology/Reproductive Center between October 2016 and March 2018. Abdominal fluid samples were obtained from 76 patients and subjected to Luminex analysis. The samples were collected from patients with OHSS (OHSS; n = 16), advanced ovarian cancer (OC; n = 22), a benign adnexal mass (BAM; n = 21), or ovarian endometriosis (EM; n = 17). Data were subjected to the non-parametric Kruskal-Wallis test and Spearman's rank correlation coefficient to identify statistical differences between the four study groups.

RESULTS

Leukocytosis and hemoconcentration were detected in the peripheral blood of OHSS patients. Abdominal fluid analysis further revealed significantly higher levels of interleukin (IL)-6, IL-8, IL-10, and transforming growth factor (TGF)-β in both the OHSS and OC groups compared to the BAM and EM groups. The highest concentration of vascular endothelial growth factor (VEGF) was detected in the OC group, while a significantly lower level was detected in the OHSS group. Moreover, VEGF levels in OC and OHSS groups were significantly elevated compared to the levels in the BAM and EM groups.

CONCLUSIONS

Vasoactive and hematogenic cytokines were present at higher levels in both the OHSS and OC abdominal fluid samples compared to the fluid samples obtained from the peritoneal cavity of the BAM patients. It is possible that these cytokines play an important role in the formation of ascites.

The relationship between ovarian endometriosis and clinical pregnancy and abortion rate based on logistic regression model

In order to study the relationship between ovarian endometriosis and clinical pregnancy, explore the correlation between endometriosis (EMT) and abortion rate and its mechanism, and provide a new theoretical basis for clinical diagnosis as well as treatment of endometriosis, in this study, pelvic endometriosis under 40 years old and have in vitro fertilization-embryo transfer (IVF-ET) operation will be selected as subjects of study. SPSS20.0 statistical software is used to analyze the data. When the measurement data between groups are compared, it is necessary to use t-test. It is necessary to use mean ± standard deviation (x¯±s) to expressed the results. When the counting data between groups is compared, it is necessary to use Chi-square test. Finally, the binomial classification logistic regression model is established by stepwise regression method to screen out the significant factors. The results show that the infertility duration of ovarian endometriosis cyst is (3.1 ± 1.9). The infertility years of other pelvic endometriosis are (3.9 ± 2.2). The infertility years of ovarian endometriosis cyst group are shorter than those of other pelvic endometriosis groups. Significant difference cannot be seen in follicle stimulating hormone (FSH) between the two groups of patients, and the basal FSH of other pelvic endometriosis groups is obviously lower in the two groups between the ages of 29 and 40 years. In the ovarian endometriotic cyst group, the significant difference can be seen (P < 0.05). Moreover, in the comparison of ovulation induction, the Gn dosage of fresh-cycle ovarian endometriosis patients is obviously higher than that of patients with ovarian endometriosis during the freezing cycle. The fertilization rate of patients with fresh cycle ovarian endometriosis is higher than that of patients with ovarian endometriosis during the freezing cycle. The two groups of patients with the factor of ovarian endometriosis after fresh embryo transplantation and the factor of fallopian tube are compared, and the abortion rate of the ovarian endometriosis group is lower than that of the fallopian tube group. Therefore, controlling the development of ovarian endometriosis can help to improve the pregnancy rate, reduce the abortion rate and improve the pregnancy outcome of patients with ovarian endometriosis.

Diagnostic value of serum D-dimer, CA125, and neutrophil-to-lymphocyte ratio in differentiating ovarian cancer and endometriosis

OBJECTIVE

To assess the utility of hematologic, inflammatory, and immunologic biomarkers for differentiating between ovarian cancer and endometriosis.

METHODS

Data were retrospectively reviewed from women diagnosed with ovarian cancer and endometriosis after ovarian cyst surgery in Zhejiang, China, 2014-2016. Serologic and hematologic biomarkers, including white blood cell count, lymphocyte count, neutrophil count, red blood cell count, hemoglobin, platelets, and D-dimer, albumin, globulin, cancer antigen 125 (CA125) and CA199 serum levels recorded pre-operatively were assessed by ROC curve and logistic regression analysis.

RESULTS

Overall, 49 women were diagnosed with ovarian cancer and 192 with endometriosis. For predicting ovarian cancer, the area under the curve (AUC) was 0.96 (95% confidence interval [CI], 0.94-0.99); sensitivity, 93.2%; specificity, 87.5%) for log(D-dimer), 0.95 (95% CI, 0.91-0.98; sensitivity, 81.3%; specificity, 96.3%) for log(CA125), and 0.92 (95% CI, 0.86-0.98; sensitivity, 92.6%; specificity, 79.2%) for neutrophil-to-lymphocyte ratio (NLR). The AUC for the combination of D-dimer, NLR, and CA125 was 0.96 (95% CI, 0.94-0.99; sensitivity, 91.6%; specificity, 89.6%).

CONCLUSION

Serum D-dimer, NLR, and CA125 were found to be potential diagnostic factors for ovarian cancer. Combined measurement of D-dimer, NLR, and CA125 might offer a convenient screening method.

Expressions of natural cytotoxicity receptor, NKG2D and NKG2D ligands in endometriosis

Pathogenesis of endometriosis is still unknown, and the relationship between NK cell activating receptors and endometriosis remains to be explored. We investigated the expression of NCRs and NKG2D in NK cells in peripheral blood (PB) and peritoneal fluid (PF) as well as expression of NKG2D ligands in endometrial cells, and illuminated their relationship with ovarian endometriosis. 20 patients with ovarian endometriosis and 13 subjects for control group were recruited. Flow cytometry was used for examining expressions of NCRs and NKG2D on NK cells. In PF with endometriosis, the expressions of NKp30 (P = 0. 006) and NKG2D (P = 0. 010) on CD56⁺NK cells were decreased, whereas the expression of NKp46 (P = 0. 040) on CD16⁺NK cells was higher than that of control. Real time PCR and Western blotting were used for detecting expression of NKG2D ligands. mRNA level of NKG2D ligands on endometrial cells showed no noticeable difference. As for protein expression, the ULBP-2 expression on eutopic endometrial cells with pelvic endometriosis was lower than that on ectopic endometrial cells and eutopic endometrial cells without endometriosis (P < 0.05), and the ULBP-3 expression on ectopic endometrial cells was lower than that on eutopic endometrial cells with or without endometriosis (P < 0.05). These findings indicate that change of NKp30, NKp46 and NKG2D on NK cells in PF and ULBP-2, 3 on endometrial cells may relate to the pathogenesis of pelvic endometriosis. Especially, change of NK cell activating receptors in PF implies that pelvic endometriosis is probably due to local immune changes.

Factors associated with ovarian endometriosis malignancy and its recurrence in Chinese women

In this study, the risk factors for ovarian endometriosis (OE) malignancy and its recurrence were explored in Chinese women. For OE malignancy occurrence, the age of marriage, abortion times, course of OE, body mass index (BMI), other benign uterine complications, and shorter parturition times were identified as risk factors using univariate analyses. Among them, age at marriage, course of OE, BMI, and decreased parturition times were identified as risk factors using multivariate analyses. For OE malignancy recurrence, the risk factors included clinical staging, histological classification, and chemotherapy by univariate analysis; and clinical stage, clear-cell carcinoma, and fewer chemotherapy cycles by multivariate analyses. In summary, we concluded that higher ages at marriage, longer courses of ovarian endometriosis, shorter parturition times, and additional benign uterine complications may increase the risk of OE malignancy. Advanced clinical stages, clear-cell carcinomas, and fewer chemotherapy cycles may promote OE malignancy recurrence. Impact statement What is already known on this subject? Endometriosis is one of the most common gynaecological diseases. Although endometriosis is not a malignant disease, endometriosis cells have characteristics similar to cancer cells. The risk of malignant transformation rates of ovarian endometriosis is said to be 1:18. However, epidemiological evidence based on large population research in ovarian endometriosis malignancy is lacking. In addition, there were few studies focussing on the long-term prognosis of ovarian endometriosis malignancies. What do the results of this study add? This study revealed the possible occurrence and recurrence risk factors of ovarian endometriosis malignancy using univariate and multivariate statistics analyses. What are the implications of these findings for clinical practice and/or further research? A clinical retrospective study with a longer follow-up period is suggested for assessing the occurrence and recurrence risk factors for ovarian endometriosis malignancies.

Mitochondria and oxidative stress in ovarian endometriosis

Endometriosis is associated with inflammatory reaction, and reactive oxidative species (ROS) are highly pro-inflammatory factors. Mitochondria are responsible for the production of ROS and energy. However, little is known about how mitochondria regulate ROS generation and energy metabolism in endometriosis. In our study, we investigated mitochondrial structure and function of ectopic endometrial stromal cells (ESCs) in ovarian endometriosis. We found mitochondria in ectopic ESCs generated more ROS and energy than controlled groups. Mitochondrial superoxide dismutase (SOD2), as an antioxidant enzyme, was found highly expressed in ectopic endometrium compared with normal endometrium. Due to its antioxidant role, SOD2 promoted the development of endometriosis by maintaining functional mitochondria to support high energetic metabolism of ectopic ESCs. We also showed that SOD2 promoted cell proliferation and migration in ovarian endometriosis. Inhibiting SOD2 expression reduced proliferation and migration of ectopic ESCS, and increased cell apoptosis. Therefore, understanding the role of mitochondrial dysfunction and SOD2 in ovarian endometriosis may provide new strategies to treat this disease.

Aberrant expression of CHL1 gene and long non-coding RNA CHL1-AS1, CHL1-AS2 in ovarian endometriosis

OBJECTIVE(S)

CHL1 (close homologue of L1 or cell adhesion molecule L1 like), also referred as CALL, is a member of the L1 gene family of neural cell adhesion molecules and belongs to immunoglobulin superfamily. This study aims to investigate the potential correlation of the CHL1 gene and the long non-coding RNAs (lncRNAs), i.e., CHL1-AS1 and CHL1-AS2, and to validate the expression patterns of CHL1 and CHL1-AS2 in ovarian endometriosis (EM).

STUDY DESIGN

Our previous microarray analyses (GSE86534) of 4 patients with ovarian EM indicated that CHL1 was the most upregulated mRNA in ectopic endometrium (EC) compared with eutopic endometrium (EU) tissues, and that its two antisense lncRNAs CHL1-AS1 and CHL1-AS2, exhibited the same expression pattern. We used a bioinformatics-based strategy to calculate the correlation among CHL1, CHL1-AS1 and CHL1-AS2. Gene set enrichment analysis (GSEA) was performed to analyze commonly enriched gene sets for CHL1-AS1 and CHL1-AS2. Using quantitative real-time polymerase chain reaction (qPCR), we examined the expression levels of CHL1 mRNA and lncRNA CHL1-AS2 in paired tissues of EC and EU from 30 EM patients and normal endometrium (NE) tissues from 27 controls using quantitative real-time polymerase chain reaction (qPCR). We also examined the expression of CHL1 protein in EC, EU and NE tissues using western blotting and immunohistochemistry (IHC).

RESULTS

CHL1, CHL1-AS1 and CHL1-AS2 were significantly correlated with each other given that the Pearson correlation values were > 0.9 using bioinformatic calculation. GSEA revealed that CHL1-AS1 and CHL1-AS2 were negatively associated with the same gene set "WAMUNYOKOLI_OVARIAN_CANCER_LMP". qPCR confirmed that the CHL1 and CHL1-AS2 expression levels were significantly higher in EC tissues than in EU and NE tissues, while they were not significantly different in EU compared with NE tissues. The relative expression levels of CHL1 and CHL1-AS2 in EC compared with EU tissues were positively significantly correlated (Pearson correlation coefficient = 0.421 and P value = 0.02). Elevated expression of CHL1 protein in EC tissues was detected by western blotting. IHC revealed that CHL1 protein expression levels enhanced in ectopic endometrial glands and stroma.

CONCLUSION(S)

Our results indicate a significant correlation among CHL1, CHL1-AS1 and CHL1-AS2, which might be involved in the development of ovarian EM and serve as novel targets for future research.

Mutation analysis of ZP1, ZP2, ZP3 and ZP4 genes in 152 Han Chinese samples with ovarian endometriosis

Endometriosis is characterized by the ectopic implant of endometrial tissue outside the uterine cavity and found in ˜35-50% of subfertile women. Previous studies have found that endometriosis had frequent defects in zona pellucida (ZP), and mutations in ZP genes could lead to ZP defects, raising the possibility that mutations in ZP genes might exist in endometriosis. We analyzed a total of 152 Han Chinese samples with ovarian endometriosis for the presence of mutations in the ZP1, ZP2, ZP3 and ZP4 genes. Two novel nonsynonymous ZP4 mutations were identified in three out of 152 (2.0%) samples: a p.M1?/(c.3 G > C) mutation in a 27- and 35-year-old sample, respectively, and a p.A433 V (c.1298C > T) mutation in a 31-year-old patient. No mutations were detected in ZP1, ZP2 or ZP3 genes; furthermore, no mutations in ZP genes were identified in 85 female control samples without endometriosis. The p.M1?/(c.3 G > C) mutation could lead to the usage of a downstream translation initiation site, while the evolutionary conservation and protein structural modeling analyses suggested that the p.A433 V mutation might be functionally important. However, there were strikingly different fertility outcomes among the three samples with ZP4 mutations: the p.A433V-mutated sample had no problem in fertility; while the p.M1?-mutated samples presented with paradoxical effects on fertility: the 35-year-old patient had a child while the 27-year-old patient was infertile, who underwent two spontaneous abortions and an implantation failure after IVF treatment. These results suggested that the potential role of ZP4 mutations on human fertility might be more complex than we thought, and other genetic and environment factors might play a role. In conclusion, we identified two novel mutations in the ZP4 gene in 2.0% of Han Chinese patients with ovarian endometriosis for the first time, our results suggested that mutations in ZP4, but not ZP1, ZP2 and ZP3, might play active roles in the pathogenesis of ovarian endometriosis, despite the mutation-carriers present with complex fertility outcomes.

Live Birth Rate after Surgical and Expectant Management of Endometriomas after In Vitro Fertilization: A Systematic Review, Meta-Analysis, and Critical Appraisal of Current Guidelines and Previous Meta-Analyses

Controversy exists regarding surgical management of endometriomas in infertile women before in vitro fertilization (IVF) because growing evidence indicates that surgery may impair the ovarian response. The objective of the present systematic review and meta-analysis was to compare surgical and expectant management of endometriomas regarding IVF outcomes. Prospective and retrospective controlled studies were found via the Cochrane Library, Embase, and MEDLINE databases. Thirteen studies (1 randomized controlled trial and 12 observational studies, N = 2878) were pooled, and similar live birth rates were observed in the surgically and expectantly managed groups (odds ratio = 0.83; 95% confidence interval [CI], 0.56-1.22; p = .98). The clinical pregnancy rates (odds ratio = 0.83; 95% CI, 0.66-1.05; p = .86), the number of mature oocytes retrieved, and the miscarriage rates were not statistically different between study groups. However, the total number of oocytes retrieved was lower in the surgery group (mean difference = -1.51; 95% CI, -2.60 to -0.43; p = .02). Findings suggest that surgical management of endometriomas before IVF therapy yields similar live birth rates as expectant management. However, future properly designed randomized controlled trials are warranted.

A functional promoter polymorphism in interleukin 12B gene is associated with an increased risk of ovarian endometriosis

OBJECTIVE

To explore the role of functional genetic variant of IL12B in the pathogenesis of ovarian endometriosis.

STUDY DESIGN

This study included 815 patients with ovarian endometriosis and 788 women in the control group. Two polymorphisms were genotyped by a method of polymerase chain reaction and ligase detection reaction. To assess the biological significance of polymorphisms, we detected the level of IL12p40 protein expression in patients' eutopic endometrial tissues using quantitative real-time polymerase chain reaction (qRT-PCR).

RESULT(S)

Compared with the CTCTAA/CTCTAA genotype, the GC/GC and GC/CTCTAA genotypes of rs17860508 could significantly increase the risk of ovarian endometriosis development (OR = 1.58, 95% CI = 1.19-2.09; OR = 1.37, 95% CI = 1.08-1.74, respectively). Moreover, the IL12B mRNA was expressed at significantly higher levels in the eutopic endometrial tissue of patients with the GC/GC genotype than in patients with the CTCTAA/CTCTAA genotype. However, the rs3212227 polymorphism may not be associated with a risk of ovarian endometriosis.

CONCLUSION(S)

The rs17860508 polymorphism in the IL12B promoter region may influence the risk of developing ovarian endometriosis by altering the endometrial expression of IL12B of in Northern Chinese women.

Comparison of Outcomes of Different Postoperative Hormone Therapy in the Treatment of Ovarian Endometriosis: A Brief Report

INTRODUCTION

Hormone therapy is widely used in the treatment of patients with ovarian endometriosis after surgery, and progestin and gonadotropin-releasing hormone (GnRH) are two of the most widely used hormones. This study aimed to compare the outcomes of progestin and GnRH in the treatment of ovarian endometriosis after surgery.

METHODS

A total of 399 patients with ovarian endometriosis were included and divided into four groups to receive different treatments. Group A received no postoperative hormone therapy; patients in group B1 and B2 were treated with different doses of norethindrone (progestin, 1.2 and 5 mg/day, respectively); patients in group C were treated with GnRH (2.0 mg every 2 weeks). Treatment outcomes including menstrual bleeding profiles, cumulative recurrence rate, incidence of complications, and endometrioma diameter in the case of recurrence were recorded and compared between groups.

RESULTS

Compared with group A, group B1, B2 and C showed significantly improved menstrual bleeding profiles and reduced cumulative recurrence rate and endometrioma diameter after recurrence. In addition, compared with group C, menstrual bleeding profiles were significantly improved and cumulative recurrence rate and endometrioma diameter were significantly reduced in group B1 and B2. No significant differences in incidence of complications during treatment were found among groups. After treatment, recurrence rate and endometrioma diameter were significantly increased in group B1, B2, and C.

CONCLUSION

Both progestin and GnRH can significantly improve the conditions of patients with ovarian endometriosis after surgery, but progestin may be a better choice. Both therapies are challenged by the increased recurrence rate and endometrioma diameter after treatment.

Short-term histopathological effects of dienogest therapy on ovarian endometriomas: in vivo, nonrandomized, controlled trial

Ovarian endometriosis is a common gynecological disorder. To date, progestins are recommended as the first-line medical treatment for symptomatic ovarian endometriosis. The aim of this study was to evaluate the main histopathological effects of short-term dienogest therapy in patients with ovarian endometriomas scheduled for surgery. A prospective, nonrandomized controlled trial, including 70 symptomatic women with single ovarian endometriotic cyst (diameter between 30-50 mm) was conducted. Women scheduled for surgery were divided into two groups, depending on the treatment established at enrollment: 36 women received progestin therapy with dienogest (P group) and 34 women received no therapy (C group). At histopathological examination necrosis, inflammation, decidualization, glandular atrophy and angiogenesis were blindly evaluated. At tissue level, decidualization was significantly more frequent in P group compared to C group (p = .001). A nonsignificant tendency (p = .29) towards a slight decreased inflammation in P group was found. No significant differences were observed between the two groups in terms of necrosis, glandular atrophy and angiogenesis. The study suggests that high decidualization rate and the tendency to reduced inflammatory reaction in the short-term administration of dienogest might contribute to its therapeutic efficacy.

Ten Principles for Safe Surgical Treatment of Ovarian Endometriosis

STUDY OBJECTIVE

To show a step-by-step laparoscopic approach for excision of an ovarian endometrioma following surgical principles for safety and maximal preservation of ovarian function.

DESIGN

Video. Medical management of ovarian endometriomas is not recommended. Operative laparoscopy is the treatment of choice. Although considered a simple procedure, ovarian cystectomy requires a precise and correct technique in order to preserve ovarian function.

SETTING

A private hospital.

PATIENT

An asymptomatic, 27-year-old woman with ultrasound imaging suggesting a 6.2 × 5.4 cm left endometrioma. Additional findings of endometriotic implants were noted in the posterior aspect of the left broad ligament, retrocervical region, Douglas pouch, and left round ligament.

INTERVENTIONS

After trocar insertion, standard inspection of the pelvic cavity with identification of endometriosis lesions and adhesions was performed. The endometrioma was drained with direct trocar puncture to avoid spillage of the endometriotic contents. Cyst aspiration and saline cleaning were executed. After drainage, a cold cut was performed at the puncture site for better identification of the cyst capsule. Through gentle traction and countertraction, the capsule was peeled from the ovarian cortex, preserving as much ovarian tissue as possible followed by careful hemostasis with a bipolar instrument. The ovary is fixed, anatomy re-established, and concomitant pelvic endometriosis resected. We aim for complete surgical excision in order to avoid leaving disease behind. The ovarian edges were reapproximated using simple interrupted stitches.

MEASUREMENTS AND MAIN RESULTS

The total procedure time was 40 minutes.

CONCLUSION

Laparoscopic endometrioma stripping offers an effective option for ovarian endometriosis treatment, reducing recurrence and being reproducible by gynecologic surgeons after proper training.

Clinical analyses of endometriosis after conservative surgery

OBJECTIVE

To assess the remission rate and outcome of pregnancy of patients who had moderate and severe ovarian endometriosis after conservative surgery. We also wished to analyze the associated factors of recurrence.

METHODS

Weconducted retrospective analyses of 199 cases with stage II-IV ovarian endometriosis who had preserved fertility under laparoscopic surgical treatment. Postoperatively, the 199 patients were divided into three groups: 43 cases underwent surgical treatment alone (group A); 47 were given a gonadotropin-releasing hormone agonist (GnRH-α) (group B), and 109 were given mifepristone (group C). Ten cases in group A were infertile, 26 cases in group B, and 38 cases in group C. All patients were followed up for 3 years. This study was approved by the Ethics Committee of Yangpu District Central Hospital.

RESULTS

In groups A, B and C, the remission rate was 58.13%, 70.21% and 60.55% and the difference not significant (P=0.384); Recurrence rates were 27.90%, 12.76% and 24.77%, and the difference between them significant (P<0.05). The recurrence rate in group B was the lowest. The natural pregnancy rate after surgery in the three study groups (untreated, GnRH-α and mifepristone) was 30%, 34.61% and 28.94% but this difference was not significant.

CONCLUSION

Surgery can improve the symptom remission rate and fertility of patients. Postoperative drug therapy does not improve the chance of pregnancy.

Ovarian endometriosis-associated stromal cells reveal persistently high affinity for iron

Ovarian endometriosis is a recognized risk for infertility and epithelial ovarian cancer, presumably due to iron overload resulting from repeated hemorrhage. To find a clue for early detection and prevention of ovarian endometriosis-associated cancer, it is mandatory to evaluate catalytic (labile) ferrous iron (catalytic Fe(II)) and to study iron manipulation in ovarian endometriotic lesions. By the use of tissues from women of ovarian endometriosis as well as endometrial tissue from women with and without endometriosis, we for the first time performed histological analysis and cellular detection of catalytic Fe(II) with a specific fluorescent probe (HMRhoNox-M), and further evaluated iron transport proteins in the human specimens and in co-culture experiments using immortalized human eutopic/ectopic endometrial stromal cells (ESCs) in the presence or absence of epithelial cells (EpCs). The amounts of catalytic Fe(II) were higher in ectopic endometrial stromal cells (ecESCs) than in normal eutopic endometrial stromal cells (n-euESCs) both in the tissues and in the corresponding immortalized ESCs. ecESCs exhibited higher transferrin receptor 1 expression both in vivo and in vitro and lower ferroportin expression in vivo than n-euESCs, leading to sustained iron uptake. In co-culture experiments of ESCs with iron-loaded EpCs, ecESCs received catalytic ferrous iron from EpCs, but n-euESCs did not. These data suggest that ecESC play a protective role for cancer-target epithelial cells by collecting excess iron, and that these characteristics are retained in the immortalized ecESCs.

The co-expression of GPER and Gankyrin in ovarian endometriosis and its correlation with the rASRM stages

OBJECTIVE

The aim of this study was to examine the expression of G protein-coupled estrogen receptor (GPER) and Gankyrin in ovarian endometriosis, analyze their clinicopathological significance, and investigate their correlation.

METHODS

Quantitative real-time polymerase chain reaction and Western blot were performed to testify mRNA and protein expression of GPER and Gankyrin in ovarian endometriosis. Immunohistochemical staining (streptavidin-peroxidase method) was conducted to determine the expression and distribution of GPER and Gankyrin protein in matched ectopic and eutopic endometrium of endometriosis and normal endometrium. We also investigated their associations with rASRM stages and the correlation between the two proteins.

RESULTS

GPER and Gankyrin were found overexpressed in ectopic endometrium of endometriosis compared with either its eutopic counterpart or endometrium from normal patients. The immunohistochemical analysis also revealed that higher expression was observed in eutopic endometrium with or without endometriosis during proliferative phase in comparison to secretory phase. These two proteins were positively correlated with the stages of endometriosis. Moreover, a significant positive correlation was found between GPER and Gankyrin both in ectopic and eutopic endometrium of the ovarian endometriosis.

CONCLUSION

GPER and Gankyrin might be implicated in the hormonal regulation of endometriosis and be associated with the severity of endometriosis. In addition, GPER and Gankyrin were found to be positively correlated, which could possibly serve as novel therapeutic targets for this disease.

Ovarian endometrioma in the adolescent: a plea for early-stage diagnosis and full surgical treatment

The incidence and severity of endometriosis in adolescent are comparable with the incidence in adult women. The mean delay between the onset of symptoms and the final diagnosis varies between 6.4 and 11.7 years. The longer the diagnosis is delayed, the more the endometriosis can progress to a more severe stage certainly in the group of patients with pelvic pain. The evolution of endometriosis and its progressivity are not predictable, and the severity of the disease is not directly related to the degree of pain. Endometriotic cysts have a detrimental effect on the ovarian reserve by the evolution in time and the surgical excision technique. Already, in small endometriotic cysts (<4 cm), loss of follicular reserve is present together with the formation of fibrosis in the cortex of the ovary. Early diagnosis of endometriosis in the adolescent deserves our full attention. Non-invasive imaging techniques like 2-D and 3-D ultrasound are helpful in the early diagnosis. Early ablative surgery is recommendable. Although laparoscopy is traditionally recommended, transvaginal laparoscopy has been shown to be most effective in ablating endometriomas with a maximum diameter of 3 cm. Early detection and intervention will contribute to a better quality of life in these adolescents and also to a lower damage of the ovarian tissue by a less invasive ablative surgery.

Transvaginal endoscopy and small ovarian endometriomas: unravelling the missing link?

The incidence of endometriosis in the infertile female is estimated to be between 20 and 50 %. Although the causal relationship between endometriosis and infertility has not been proven, it is generally accepted that the disease impairs reproductive outcome. Indirect imaging techniques and transvaginal laparoscopy now offer the possibility of an early stage diagnosis. Although it remains debated whether the disease is progressive, treatment in an early stage is recommendable as it carries less risk for ovarian damage, hence premature ovarian failure. Under water, inspection with the technique of transvaginal hydrolaparoscopy (THL) accurately shows the invagination of the ovarian cortex as minimal superficial lesions but with the presence of well-differentiated endometrial like tissue at the base, the lateral walls and especially the inner edges of the small endometrioma. An inflammatory environment is responsible for the formation of connecting adhesions with the broad ligament and lateral wall with invasion of endometrial-like tissue and formation of adenomyotic lesions. In around 50 % of the small endometriomas, adhesiolysis is necessary at the site of invagination with opening of the cyst, to free the chocolate content and hereby recognize the underlying endometrioma. The detailed inspection of these early-stage endometriotic lesions at THL reunites the hypothesis of Sampson with the observation of Hughesdon.