Occult microscopic endometriosis: undetectable by laparoscopy in normal peritoneum

Lysine acetyltransferase 14 mediates TGF-β-induced fibrosis in ovarian endometrioma via co-operation with serum response factor

BACKGROUND

Fibrogenesis within ovarian endometrioma (endometrioma), mainly induced by transforming growth factor-β (TGF-β), is characterized by myofibroblast over-activation and excessive extracellular matrix (ECM) deposition, contributing to endometrioma-associated symptoms such as infertility by impairing ovarian reserve and oocyte quality. However, the precise molecular mechanisms that underpin the endometrioma- associated fibrosis progression induced by TGF-β remain poorly understood.

METHODS

The expression level of lysine acetyltransferase 14 (KAT14) was validated in endometrium biopsies from patients with endometrioma and healthy controls, and the transcription level of KAT14 was further confirmed by analyzing a published single-cell transcriptome (scRNA-seq) dataset of endometriosis. We used overexpression, knockout, and knockdown approaches in immortalized human endometrial stromal cells (HESCs) or human primary ectopic endometrial stromal cells (EcESCs) to determine the role of KAT14 in TGF-β-induced fibrosis. Furthermore, an adeno-associated virus (AAV) carrying KAT14-shRNA was used in an endometriosis mice model to assess the role of KAT14 in vivo.

RESULTS

KAT14 was upregulated in ectopic lesions from endometrioma patients and predominantly expressed in activated fibroblasts. In vitro studies showed that KAT14 overexpression significantly promoted a TGF-β-induced profibrotic response in endometrial stromal cells, while KAT14 silencing showed adverse effects that could be rescued by KAT14 re-enhancement. In vivo, Kat14 knockdown ameliorated fibrosis in the ectopic lesions of the endometriosis mouse model. Mechanistically, we showed that KAT14 directly interacted with serum response factor (SRF) to promote the expression of α-smooth muscle actin (α-SMA) by increasing histone H4 acetylation at promoter regions; this is necessary for TGF-β-induced ECM production and myofibroblast differentiation. In addition, the knockdown or pharmacological inhibition of SRF significantly attenuated KAT14-mediating profibrotic effects under TGF-β treatment. Notably, the KAT14/SRF complex was abundant in endometrioma samples and positively correlated with α-SMA expression, further supporting the key role of KAT14/SRF complex in the progression of endometrioma-associated fibrogenesis.

CONCLUSION

Our results shed light on KAT14 as a key effector of TGF-β-induced ECM production and myofibroblast differentiation in EcESCs by promoting histone H4 acetylation via co-operating with SRF, representing a potential therapeutic target for endometrioma-associated fibrosis.

Neonatal uterine bleeding: Risk factors and its association with endometriosis-related symptoms later in life

OBJECTIVE

We examined the prevalence and risk factors in association with neonatal uterine bleeding (NUB) by retrospective search of contemporary and historical medical records and investigated the possible association between the history of NUB at birth and endometriosis-related symptoms later in life who are now young women.

STUDY DESIGN

This was a retrospective case-controlled cohort study and prospective evaluation of web-based questionnaire survey on symptoms related to endometriosis among young women born with and without NUB. Multiple regression analysis was performed incorporating various confounding variables that may influence the occurrence of NUB or the reporting of endometriosis symptoms later in life.

RESULTS

Among the 1093 female neonates born between 1996 and 2000, 105 of them had NUB, yielding with a prevalence of 9.6 %. Of the 807 female babies born between 2013 and 2017, 25 (3.1 %) had NUB. Multiple Logistic regression analysis indicated that younger age of the mother [odds ratio (OR) = 0.92, 95 % confidence interval (CI) = 0.85-1.00, P = 0.048] and longer gestational age of 39 weeks (OR = 3.04, 95 % CI = 1.43-6.45, P = 0.004) and of ≥ 40 weeks (OR = 4.54, 95 % CI = 2.20-9.39, P < 0.0001) of gestation were significantly associated with the occurrence of NUB. While the possibility of recall bias cannot be ruled out, newborn females who had a history of NUB appeared to complain of various endometriosis-related symptoms later in life during adulthood.

CONCLUSIONS

We confirmed the validity of the reported prevalence and risk factors of NUB. NUB indeed occurs with a prevalence of 3-10% during the historical and contemporary period. Longer gestational age and younger maternal age may be considered as high-risk factors for the occurrence of NUB. The clinical relevance of our findings remains to be elucidated. Future prospective studies, preferably with larger sample sizes and the inclusion of NUB cases after discharge from the hospital, may further illuminate some unresolved issues. We also need to confirm the endometriosis-related symptoms in women with and without history of NUB via more definitive diagnosis such as imaging and histology.

New concepts on the etiology of endometriosis

Endometriosis is a serious, chronic disorder where endometrial tissue grows outside the uterus, causing severe pelvic pain and infertility. It affects 11% of women. Endometriosis is a multifactorial disorder of unclear etiology, although retrograde menstruation plays a major role. It has a genetic component with over 40 genetic risk factors mapped, although their mechanism of action is still emerging. New evidence suggests a role for retrograde menstruation of endometrial stem/progenitor cells, now that identifying markers of these cells are available. Recent lineage tracing and tissue clearing microscopy and 3D reconstruction has provided new understanding of endometrial glandular structure, particularly the horizontal orientation and interconnection of basalis glands. New sequencing technologies, particularly whole genome DNA sequencing are revealing somatic mutations, including in cancer driver genes, in normal and eutopic endometrium of patients with endometriosis, as well as ectopic endometriotic lesions. Methylome sequencing is offering insight into the regulation of genes and the role of the environmental factors. Single cell RNA sequencing reveals the transcriptome of individual endometrial cells, shedding new light on the diversity and range of cellular subpopulations of the major cell types present in the endometrium and in endometriotic lesions. New endometrial epithelial organoid cultures replicating glandular epithelium are providing tractable models for studying endometriosis. Organoids derived from menstrual fluid offer a non-invasive source of endometrial tissue and a new avenue for testing drugs and developing personalized medicine for treating endometriosis. These new approaches are rapidly advancing our understanding of endometriosis etiology.

Association Between Laparoscopic Appearance of Superficial Endometriosis, Positive Histology, and Systemic Hormone Use

STUDY OBJECTIVE

To assess the association between laparoscopic appearance of superficial endometriosis lesions, histopathology, and systemic hormone use.

DESIGN

Retrospective study.

SETTING

Tertiary care academic medical center.

PATIENTS

We identified 266 women who underwent laparoscopic surgery at an endometriosis center with excision of lesions consistent with possible superficial endometriosis between September 2015 and November 2018.

INTERVENTIONS

Appearance of the peritoneal lesions was confirmed with review of surgical videos and correlated with each pathology specimen. Lesions were dichotomized on positive or negative pathology assessment. All pathology-positive lesions were further dichotomized by hormone use within 1 month of surgery.

MEASUREMENTS AND MAIN RESULTS

A total of 841 lesions were biopsied from included subjects during the study period. Of those, 251 biopsies were negative, and 590 were positive for endometriosis on pathology assessment. Lesions had significantly higher odds of positive histology when they were red (odds ratio [OR], 1.70; 95% confidence interval [CI], 1.17-2.48), white (OR, 1.99; 95% CI, 1.47-2.70), blue/black (OR, 2.98; 95% CI, 2.00-4.44), or puckering (OR, 9.78; 95% CI, 2.46-38.91) in appearance. The following combined characteristics had significantly higher odds of positive histology: white and blue (OR, 5.98; 95% CI, 2.97-12.02), red and white (OR, 2.22; 95% CI, 1.38-3.56), red and blue (OR, 4.11; 95% CI, 1.83-9.24), and clear and white (OR, 8.77; 95% CI, 1.17-66.02). Among positive biopsies, those with hormone exposure were more likely to have clear lesions than those without hormone use (OR, 3.36; 95% CI, 1.54-7.34) and were 2.89 times more likely to have clear and white lesions (95% CI, 1.07-7.85).

CONCLUSION

Although lesions suspicious for endometriosis may have differing rates of positive pathology based on appearance, no lesion characteristic was able to exclude the possibility of endometriosis. In addition, hormone use may influence lesion appearance at the time of surgery, with clear lesions more prevalent. These data have implications for appropriate identification of endometriosis at the time of laparoscopy to ensure accurate diagnosis and complete treatment of disease.

Strengths and limitations of diagnostic tools for endometriosis and relevance in diagnostic test accuracy research

Endometriosis is a chronic systemic disease that can cause pain, infertility and reduced quality of life. Diagnosing endometriosis remains challenging, which yields diagnostic delays for patients. Research on diagnostic test accuracy in endometriosis can be difficult due to verification bias, as not all patients with endometriosis undergo definitive diagnostic testing. The purpose of this State-of-the-Art Review is to provide a comprehensive update on the strengths and limitations of the diagnostic modalities used in endometriosis and discuss the relevance of diagnostic test accuracy research pertaining to each. We performed a comprehensive literature review of the following methods: clinical assessment including history and physical examination, biomarkers, diagnostic imaging, surgical diagnosis and histopathology. Our review suggests that, although non-invasive diagnostic methods, such as clinical assessment, ultrasound and magnetic resonance imaging, do not yet qualify formally as replacement tests for surgery in diagnosing all subtypes of endometriosis, they are likely to be appropriate for advanced stages of endometriosis. We also demonstrate in our review that all methods have strengths and limitations, leading to our conclusion that there should not be a single gold-standard diagnostic method for endometriosis, but rather, multiple accepted diagnostic methods appropriate for different circumstances. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Pathogenesis of Human Adenomyosis: Current Understanding and Its Association with Infertility

The aim of this review article was to summarize our current understanding on the etiologies and pathogenesis of human adenomyosis and to clarify the relative association between adenomyosis and infertility. The exact pathogenesis of adenomyosis is still elusive. Among different reported concepts, direction invagination of gland cells from the basalis endometrium deep into myometrium is the most widely accepted opinion on the development of adenomyosis. According to this concept, endometrial epithelial cells and changed fibroblasts, abnormally found in the myometrium in response to repeated tissue injury and/or disruption at the endometrium-myometrium interface (EMI), elicit hyperplasia and hypertrophy of the surrounding smooth muscle cells. In this review, a comprehensive review was performed with a literature search using PubMed for all publications in English and Japanese (abstract in English), related to adenomyosis and infertility, from inception to April 2021. As an estrogen-regulated factor, hepatocyte growth factor (HGF) exhibits multiple functions in endometriosis, a disease commonly believed to arise from the functionalis endometrium. As a mechanistic basis of gland invagination, we investigated the role of HGF, either alone or in combination with estrogen, in the occurrence of epithelial-mesenchymal transition (EMT) in adenomyosis. Aside from microtrauma at the EMI, metaplasia of displaced Müllerian remnants, differentiation of endometrial stem/progenitor cells within the myometrium and somatic mutation of some target genes have been put forward to explain how adenomyosis develops. In addition, the possible role of microRNAs in adenomyosis is also discussed. Besides our knowledge on the conventional classification (focal and diffuse), two recently proposed classifications (intrinsic and extrinsic) of adenomyosis and the biological differences between them have been described. Although the mechanistic basis is unclear, the influence of adenomyosis on fertility outcome is important, especially considering the recent tendency to delay pregnancy among women. Besides other proposed mechanisms, a recent transmission election microscopic (TEM) study indicated that microvilli damage and an axonemal alteration in the apical endometria of human adenomyosis, in response to endometrial inflammation, may be involved in negative fertility outcomes. We present a critical analysis of the literature data concerning the mechanistic basis of infertility in women with adenomyosis and its impact on fertility outcome.

Thai Interest Group for Endometriosis (TIGE) consensus statement on endometriosis-associated pain

This consensus statement has been developed by the Thai Interest Group for Endometriosis (TIGE) for use by Thai clinicians in the diagnosis and management of endometriosis. TIGE is a group of clinical and academic gynaecologists with a particular interest in endometriosis. Endometriosis is an oestrogen-dependent inflammatory disease which causes chronic symptoms such as dysmenorrhoea, chronic pelvic pain, dyspareunia and subfertility, and it is common in reproductive-age women. There is limited overall data on its prevalence in different clinical settings in Thailand, but it is clear that the disease causes significant problems for patients in terms of their working lives, fertility, and quality of life, as well as placing a great burden on national healthcare resources. Decisions about selecting the appropriate treatment for women with endometriosis depend on many factors including the age of the patient, the extent and severity of disease, concomitant conditions, economic status, patient preference, access to medication, and fertility need. Several hormonal treatments are available but no consensus has been reached about the best option for long-term prevention of recurrence. Bearing in mind differences in environment, genetics, and access to the healthcare system, this treatment guideline has been tailored to the particular circumstances of Thai women.

A Revised Stem Cell Theory for the Pathogenesis of Endometriosis

During the past decade, a stem cell-based hypothesis has emerged (among many others) to explain the pathogenesis of endometriosis. The initial hypothesis proposed that endometriosis arose from a single or a few specific cells with stem cell properties, including self-renewal and multi-lineage cell differentiation. The origins of the endometriosis-initiating stem cells were thought to be the bone marrow, uterine endometrium, and other tissues. Based on the implantation or metastatic theory in combination with the initial stem cell theory, one or a few multipotent stem/progenitor cells present in the eutopic endometrium or bone marrow translocate to ectopic sites via fallopian tubes during menstruation, vasculolymphatic routes, or through direct migration and invasion. Subsequently, they give rise to endometriotic lesions followed by differentiation into various cell components of endometriosis, including glandular and stromal cells. Recent somatic mutation analyses of deep infiltrating endometriosis, endometrioma, and eutopic normal endometrium using next-generation sequencing techniques have redefined the stem cell theory. It is now proposed that stem/progenitor cells of at least two different origins—epithelium and stroma—sequentially, differentially, but coordinately contribute to the genesis of endometriosis. The dual stem cell theory on how two (or more) stem/progenitor cells differentially and coordinately participate in the establishment of endometriotic lesions remains to be elucidated. Furthermore, the stem/progenitor cells involved in this theory also remain to be identified. Given that the origin of endometriosis is eutopic endometrium, the candidate cells for endometriotic epithelium-initiating cells are likely to be endometrial epithelial cells positive for either N-cadherin or SSEA-1 or both. The candidate cells for endometriotic stroma-initiating cells may be endometrial mesenchymal stem cells positive for SUSD2. Endometrial side population cells are also a possible candidate because they contain unipotent or multipotent cells capable of behaving as endometrial epithelial and stromal stem/progenitor cells.

Near-Infrared Imaging With Indocyanine Green for the Treatment of Endometriosis: Results From the Gre-Endo Trial

Introduction

A current challenge for endometriosis surgery is to correctly identify the localizations of disease, especially when small or hidden (occult endometriosis), and to exactly define their real extension. The use of near-infrared radiation imaging (NIR) after injection of indocyanine green (ICG) represents one of the most encouraging method. The aim of this study is to assess the diagnostic value of NIR-ICG imaging in the surgical treatment of endometriosis compared with the standard of treatment.

Material and Methods

The Gre-Endo trial is a prospective, single-arm study (NCT03332004). After exploring the operatory field using the white light (WL) mode, patients were injected with ICG and then observed in NIR mode. All suspected areas were classified and chronicled according to lesions visualized only in WL, NIR-ICG, or in the combination of both. Lesion not visualized in WL was considered as suspect occult lesion (s-OcL). In addition, a random control biopsy from an apparent negative peritoneum visualized in WL and NIR-ICG imaging was taken for all patients (control cases). All lesions removed were considered “suspect endometriosis” until pathology.

Results

Fifty-one patients were enrolled between January 2016 and October 2019. A total of 240 suspected lesions have been identified with both methods (WL + NIR-ICG). Two hundred and seven (86.2%) lesions out of the overall 240 were visualized with WL imaging, and 200 were confirmed to be pathologic (true positive for WL). The remaining 33/240 (13.75%) (false negative for WL) lesions were identified only with NIR-ICG imaging and collected as s-OcL. All 33 s-OcLs removed were confirmed to be pathologic (c-OcL = 100%). NIR-ICG vision showed PPV of 98.5%, NPV of 87.1%, Se of 87%, and Sp of 98.5%, confirming that this kind of imaging is an excellent diagnostic and screening test (p = 0.001 and p = 0.835, according to McNemar’s and Cohen’s kappa tests, respectively).

Conclusions

The use of NIR-ICG vision alone and combined with WL showed good results in intraoperative detection rate and fluorescence-guided surgery of endometriosis. Furthermore, NIR-ICG allowed surgeons to remove occult lesions that otherwise would remain, leading to possible greater postoperative pain and a higher risk of persistence and relapse.

Environmental Factors and Endometriosis

Endometriosis is a common disease, affecting up to 60-80% of women, with pelvic pain or/and infertility. Despite years of studies, its pathogenesis still remains enigmatic. Genetic, hormonal, environmental, and lifestyle-related factors may be involved in its pathogenesis. Thus, the design of the review was to discuss the possible role of environmental factors in the development of endometriosis. The results of individual studies greatly differ, making it very difficult to draw any definite conclusions. There is no reasonable consistency in the role of environmental factors in endometriosis etiopathogenesis.

Levofloxacin or gonadotropin releasing hormone agonist treatment decreases intrauterine microbial colonization in human endometriosis

OBJECTIVE

We examined the hypothesis that antibiotic treatment with or without gonadotropin releasing hormone agonist (GnRHa) may decrease intrauterine infection with consequent decrease in tissue inflammation, cell proliferation and angiogenesis in human endometriosis.

STUDY DESIGN

This is a prospective non-randomized observational study. Endometrial/endometriotic samples were collected during surgery from 53 women with endometriosis and 47 control women who were treated with levofloxacin (LVFX, 500 mg, once per os) or GnRHa (1.88 mg/IM for 3 months) before surgery. Endometrial samples were analyzed by broad-range polymerase-chain reaction (PCR) amplification of bacteria targeting V5-V6 region of 16S rRNA gene. Immunohistochemical analysis was performed using antibodies against CD138 (Syndecan-1, a marker of plasma cells), CD68 (marker of macrophages), Ki-67 (cell proliferation marker), and CD31 (vascular cells marker).

RESULTS

16S rDNA metagenome assay indicated that treatment with either of LVFX or GnRHa + LVFX significantly decreased some components of major bacterial genera comparing to untreated group. In women with endometriosis, treatment with either of LVFX or GnRHa + LVFX significantly decreased Gardnerella, Prevotella, Acidibactor, Atopobium, Megasphaera, and Bradyrhizobium (p < 0.05 for each) comparing to untreated group. Cochran-Mantel-Haenszel test indicated that occurrence rate of chronic endometritis was significantly decreased after GnRHa + LVFX treatment comparing to GnRHa treatment group (p = 0.041). These findings were coincided with significantly decreased CD68-stained macrophage infiltration, Ki-67- stained cell proliferation and CD31-stained micro-vessel density in endometria and endometriotic lesions with histology proven improvement in the morphological appearance of ovarian endometrioma.

CONCLUSIONS

These findings suggest that clinical administration of a broad-spectrum antibiotic with or without GnRHa may be effective in improving uterine infection with decrease of tissue inflammation, cell proliferation, and angiogenesis in human endometriosis.

A systematic review of toll-like receptors in endometriosis

INTRODUCTION

The pathogen-associated molecular patterns and the danger-associated molecular patterns are possibly responsible for the activation of the inflammatory process in endometriosis through the activation of toll-like receptors (TLRs).

OBJECTIVE

The aim of this systematic review was to critically analyze the findings of published articles on TLRs in endometriosis.

METHODS

The keywords used were "endometriosis" and "toll-like" and the search was performed in Pubmed, Scielo and Lilacs databases. This study followed the PRISMA guidelines and the risk of bias of articles was conducted by Newcastle-Ottawa scale (NOS).

RESULTS

Overall, the studies analyzed in this review point toward an increased expression of TLRs two, four and nine in women with endometriosis. Among all TLRs, TLR4 was the most cited receptor.

CONCLUSION

Despite the evidence demonstrating elevated TLR levels in endometriosis, the relationship with the disease is still unclear and needs to be clarified in further studies about innate immune response.

Cancer-associated mutations in endometriosis: shedding light on the pathogenesis and pathophysiology

BACKGROUND

Endometriosis is a benign gynaecological disease. Thus, it came as a complete surprise when it was reported recently that the majority of deep endometriosis lesions harbour somatic mutations and a sizeable portion of them contain known cancer-associated mutations (CAMs). Four more studies have since been published, all demonstrating the existence of CAMs in different subtypes of endometriosis. While the field is still evolving, the confirmation of CAMs has raised many questions that were previously overlooked.

OBJECTIVE AND RATIONALE

A comprehensive overview of CAMs in endometriosis has been produced. In addition, with the recently emerged understanding of the natural history of endometriotic lesions as well as CAMs in normal and apparently healthy tissues, this review attempts to address the following questions: Why has there been such a wild discrepancy in reported mutation frequencies? Why does ectopic endometrium have a higher mutation rate than that of eutopic endometrium? Would the presence of CAMs in endometriotic lesions increase the risk of cancer to the bearers? Why do endometriotic epithelial cells have much higher mutation frequencies than their stromal counterpart? What clinical implications, if any, do the CAMs have for the bearers? Do these CAMs tell us anything about the pathogenesis and/or pathophysiology of endometriosis?

SEARCH METHODS

The PubMed database was searched, from its inception to September 2019, for all papers in English using the term 'endometriosis and CAM', 'endometriosis and cancer-driver mutation', 'somatic mutations', 'fibrosis', 'fibrosis and epigenetic', 'CAMs and tumorigenesis', 'somatic mutation and normal tissues', 'oestrogen receptor and fibrosis', 'oxidative stress and fibrosis', 'ARID1A mutation', and 'Kirsten rat sarcoma mutation and therapeutics'. All retrieved papers were read and, when relevant, incorporated into the review results.

OUTCOMES

Seven papers that identified CAMs in endometriosis using various sequencing methods were retrieved, and their results were somewhat different. Yet, it is apparent that those using microdissection techniques and more accurate sequencing methods found more CAMs, echoing recent discoveries that apparently healthy tissues also harbour CAMs as a result of the replicative aging process. Hence endometriotic lesions, irrespective of subtype, if left intact, would generate CAMs as part of replicative aging, oxidative stress and perhaps other factors yet to be identified and, in some rare cases, develop cancer. The published data still are unable to paint a clear picture on pathogenesis of endometriosis. However, since endometriotic epithelial cells have a higher turnover than their stromal counterpart due to cyclic bleeding, and since the endometriotic stromal component can be formed by refresh influx of mesenchymal cells through epithelial-mesenchymal transition, endothelial-mesenchymal transition, mesothelial-mesenchymal transition and other processes as well as recruitment of bone-marrow-derived stem cells and outflow due to smooth muscle metaplasia, endometriotic epithelial cells have much higher mutation frequencies than their stromal counterpart. The epithelial and stromal cellular components develop in a dependent and co-evolving manner. Genes involved in CAMs are likely to be active players in lesional fibrogenesis, and hyperestrogenism and oxidative stress are likely drivers of both CAMs and fibrogenesis. Finally, endometriotic lesions harbouring CAMs would conceivably be more refractory to medical treatment, due, in no small part, to their high fibrotic content and reduced vascularity and cellularity.

WIDER IMPLICATIONS

The accumulating data on CAMs in endometriosis have shed new light on the pathogenesis and pathophysiology of endometriosis. They also suggest new challenges in management. The distinct yet co-evolving developmental trajectories of endometriotic stroma and epithelium underscore the importance of the lesional microenvironment and ever-changing cellular identity. Mutational profiling of normal endometrium from women of different ages and reproductive history is needed in order to gain a deeper understanding of the pathogenesis. Moreover, one area that has conspicuously received scant attention is the epigenetic landscape of ectopic, eutopic and normal endometrium.

The epidemiology of endometriosis is poorly known as the pathophysiology and diagnosis are unclear

As the diagnosis requires a laparoscopy, we only have data in women with pain and/or infertility. Endometriosis has been considered to be a single disease defined as 'endometrium like glands and stroma outside the uterus'. However, subtle, typical, cystic ovarian and deep endometriosis lesions should be considered to be different pathologies which occur in all combinations and with different severities. All large datasets, especially those based on hospital discharge records, consider endometriosis to be a single disease without taking into account severity. In particular, the variable prevalence and recognition of subtle lesions is problematic. Reliable surgical data are small series not permitting multivariate analysis. Endometriosis is a hereditary disease. The oxidative stress of heavy menstrual bleeding with retrograde menstruation and an altered pelvic microbiome are probably associated with increasingly severe endometriosis. Whether the prevalence is increasing, or whether endometriosis is associated with fat intake or an increased risk of cardiovascular disease is unclear.

Prevalence of occult microscopic endometriosis in clinically negative peritoneum during laparoscopy for chronic pelvic pain

OBJECTIVE

 To determine the prevalence of occult microscopic endometriosis in patients with chronic pelvic pain and negative laparoscopy.

METHODS

A retrospective cross-sectional study included women who underwent laparoscopic evaluation for chronic pelvic pain by three fellowship-trained gynecologic surgeons at a community hospital from January 2011 to December 2016. The aim was to evaluate the prevalence of microscopic endometriosis in this population.

RESULTS

 In 142 patients with clinically negative peritoneum on laparoscopy, 39% had occult microscopic endometriosis. Cramping pain score during menses was found to be lower in the positive biopsy group (6.9 vs 8.0, P=0.046). No differences were appreciated in age of menarche, pain during various parts of the menstrual cycle, or duration of symptoms. The biopsy-positive group had a younger age at time of evaluation, although not statistically significant (P=0.179). Current use of hormones affected neither biopsy results nor menstrual or pain characteristics. Detection was similar between robotic and laparoscopic cases and operative morbidity was minimal.

CONCLUSION

Occult microscopic endometriosis may be present in approximately 39% of patients with clinically negative appearing peritoneum undergoing laparoscopy for chronic pelvic pain. Given this, biopsies should be performed in patients undergoing laparoscopy who do not have visible lesions.

Evidence in Support for the Progressive Nature of Ovarian Endometriomas

CONTEXT

Whether endometriosis is a progressive disease is a highly contentious issue. While progression is reported to be unlikely in asymptomatic deep endometriosis, progression in symptomatic deep endometriosis has recently been reported, especially in menstruating women. However, pathophysiological reasons for these differences are unclear.

OBJECTIVE

This study was designed to investigate whether ovarian endometrioma (OE) is progressive or not.

SETTING, DESIGN, PATIENTS, INTERVENTION AND MAIN OUTCOME MEASURES

Thirty adolescent patients, aged 15 to 19 years, and 32 adult patients, aged 35 to 39 years, all laparoscopically and histologically diagnosed with OE, were recruited into this study after informed consent. Their demographic and clinical information were collected. Their OE tissue samples were collected and subjected to immunohistochemical analysis for E-cadherin, α-smooth muscle actin (α-SMA), desmin, and adrenergic receptor β2 (ADRB2), as well as quantification of lesional fibrosis by Masson trichrome staining.

RESULTS

OE lesions from the adolescent and adult patients are markedly different, with the latter exhibiting more extensive and thorough progression and more extensive fibrosis, suggesting that lesions in adults progressed to a more advanced stage. Adult lesions and higher staining level of α-SMA and ADRB2 are positively associated with the extent of lesional fibrosis, while the lesion size and the E-cadherin staining are negatively associated.

CONCLUSIONS

Our data provide a more definitive piece of evidence suggesting that OE is a progressive disease, since the adult lesions have had a longer time to progress. In addition, the pace of progression depends on lesional age as well as the severity of endometriosis-associated dysmenorrhea, if any.

Peritoneal Retraction Pocket Defects and Their Important Relationship with Pelvic Pain and Endometriosis

OBJECTIVE

The objective of this video is to demonstrate different clinical presentations of peritoneal defects (peritoneal retraction pockets) and their anatomic relationships with the pelvic innervation, justifying the occurrence of some neurologic symptoms in association with these diseases.

DESIGN

Surgical demonstration of complete excision of different types of peritoneal retraction pockets and a comparison with a laparoscopic retroperitoneal cadaveric dissection of the pelvic innervation.

SETTING

Private hospital in Curitiba, Paraná, Brazil.

INTERVENTIONS

A pelvic peritoneal pocket is a retraction defect in the surface of the peritoneum of variable size and shapes [1]. The origin of defects in the pelvic peritoneum is still unknown [2]. It has been postulated that it is the result of peritoneal irritation or invasion by endometriosis, with resultant scarring and retraction of the peritoneum [3,4]. It has also been suggested that a retraction pocket may be a cause of endometriosis, where the disease presumably settles in a previously altered peritoneal surface [5]. These defects are shown in many studies to be associated with pelvic pain, dyspareunia, and secondary dysmenorrhea [1-4]. Some studies have shown that the excision of these peritoneal defect improves pain symptoms and quality of life [5]. It is important to recognize peritoneal pockets as a potential manifestation of endometriosis because in some cases, the only evidence of endometriosis may be the presence of these peritoneal defects [6]. In this video, we demonstrate different types of peritoneal pockets and their close relationship with pelvic anatomic structures. Case 1 is a 29-year-old woman, gravida 0, with severe dysmenorrhea and catamenial bowel symptoms (bowel distension and diarrhea/constipation) that were unresponsive to medical treatment. Imaging studies were reported as normal, and a laparoscopy showed a posterior cul-de-sac peritoneal pocket infiltrating the pararectal fossa, with extension to the lateral border of the rectum. Case 2 is a cadaveric dissection of a posterior cul-de-sac peritoneal pocket infiltrating the pararectal fossa, with extension to the pelvic sidewall. After dissection of the obturator fossa, we can observe that the pocket is close to the sacrospinous ligament, pudendal nerve, and some sacral roots. Case 3 is a 31-year-old woman, gravida 1, para 1, with severe dysmenorrhea that was unresponsive to medical treatment and catamenial bowel symptoms (catamenial bowel distention and diarrhea). Imaging studies were reported as normal and a laparoscopy showed left uterosacral peritoneal pocket infiltrating the pararectal fossa in close proximity to the rectal wall. Case 4 is a cadaveric dissection of the ovarian fossa and the obturator fossa showing the proximity between these structures. Case 5 is a 35-year-old woman, gravida 0, with severe dysmenorrhea that was unresponsive to medical treatment, referring difficulty, and pain when walking only during menstruation. A neurologic physical examination revealed weakness in thigh adduction, and the magnetic resonance imaging showed no signs of endometriosis. During laparoscopy, we found a peritoneal pocket infiltrating the ovarian fossa, with involvement in the area between the umbilical ligament and the uterine artery. This type of pocket can easily reach the obturator nerve. Because the obturator nerve and its branches supply the muscle and skin of the medial thigh [7,8], patients may present with thigh adduction weakness or difficulty ambulating [9,10]. Case 6 is a cadaveric dissection of the sacrospinous ligament and the pudendal nerve from a medial approach, between the umbilical artery and the iliac vessels. Case 7 is a 34-year-old woman, gravida 1, para 1, with severe dysmenorrhea and catamenial bowel symptoms as well as deep dyspareunia. The transvaginal ultrasound showed focal adenomyosis and a 2-cm nodule, 9-cm apart from the anal verge, affecting 30% of the bowel circumference. In the laparoscopy, we found a posterior cul-de-sac retraction pocket associated with a large deep endometriosis nodule affecting the vagina and the rectum. In all cases, endometriosis was confirmed by histopathology, and in a 6-month follow-up, all patients showed improvement of bowel, pain, and neurologic symptoms.

CONCLUSION

Peritoneal pockets can have different clinical presentations. Depending on the topography and deepness of infiltration, they can be the cause of some neurologic symptoms associated with endometriosis pain. With this video, we try to encourage surgeons to totally excise these lesions and raise awareness about the adjacent key anatomic structures that can be affected.

Endometriosis and nuclear receptors

BACKGROUND

Endometriosis is recognized as a steroid-dependent disorder; however, the precise roles of nuclear receptors (NRs) in steroid responsiveness and other signaling pathways are not well understood.

OBJECTIVE AND RATIONALE

Over the past several years, a number of paradigm-shifting breakthroughs have occurred in the area of NRs in endometriosis. We review and clarify new information regarding the mechanisms responsible for: (i) excessive estrogen biosynthesis, (ii) estrogen-dependent inflammation, (iii) defective differentiation due to progesterone resistance and (iv) enhanced survival due to deficient retinoid production and action in endometriosis. We emphasize the roles of the relevant NRs critical for these pathological processes in endometriosis.

SEARCH METHODS

We conducted a comprehensive search using PubMed for human, animal and cellular studies published until 2018 in the following areas: endometriosis; the steroid and orphan NRs, estrogen receptors alpha (ESR1) and beta (ESR2), progesterone receptor (PGR), steroidogenic factor-1 (NR5A1) and chicken ovalbumin upstream promoter-transcription factor II (NR2F2); and retinoids.

OUTCOMES

Four distinct abnormalities in the intracavitary endometrium and extra-uterine endometriotic tissue underlie endometriosis progression: dysregulated differentiation of endometrial mesenchymal cells, abnormal epigenetic marks, inflammation activated by excess estrogen and the development of progesterone resistance. Endometriotic stromal cells compose the bulk of the lesions and demonstrate widespread epigenetic abnormalities. Endometriotic stromal cells also display a wide range of abnormal NR expression. The orphan NRs NR5A1 and NR2F2 compete to regulate steroid-synthesizing genes in endometriotic stromal cells; NR5A1 dominance gives rise to excessive estrogen formation. Endometriotic stromal cells show an abnormally low ESR1:ESR2 ratio due to excessive levels of ESR2, which mediates an estrogen-driven inflammatory process and prostaglandin formation. These cells are also deficient in PGR, leading to progesterone resistance and defective retinoid synthesis. The pattern of NR expression, involving low ESR1 and PGR and high ESR2, is reminiscent of uterine leiomyoma stem cells. This led us to speculate that endometriotic stromal cells may display stem cell characteristics found in other uterine tissues. The biologic consequences of these abnormalities in endometriotic tissue include intense inflammation, defective differentiation and enhanced survival.

WIDER IMPLICATIONS

Steroid- and other NR-related abnormalities exert genome-wide biologic effects via interaction with defective epigenetic programming and enhance inflammation in endometriotic stromal cells. New synthetic ligands, targeting PGR, retinoic acid receptors and ESR2, may offer novel treatment options.

Endometriosis

Pelvic endometriosis is a complex syndrome characterized by an estrogen-dependent chronic inflammatory process that affects primarily pelvic tissues, including the ovaries. It is caused when shed endometrial tissue travels retrograde into the lower abdominal cavity. Endometriosis is the most common cause of chronic pelvic pain in women and is associated with infertility. The underlying pathologic mechanisms in the intracavitary endometrium and extrauterine endometriotic tissue involve defectively programmed endometrial mesenchymal progenitor/stem cells. Although endometriotic stromal cells, which compose the bulk of endometriotic lesions, do not carry somatic mutations, they demonstrate specific epigenetic abnormalities that alter expression of key transcription factors. For example, GATA-binding factor-6 overexpression transforms an endometrial stromal cell to an endometriotic phenotype, and steroidogenic factor-1 overexpression causes excessive production of estrogen, which drives inflammation via pathologically high levels of estrogen receptor-β. Progesterone receptor deficiency causes progesterone resistance. Populations of endometrial and endometriotic epithelial cells also harbor multiple cancer driver mutations, such as KRAS, which may be associated with the establishment of pelvic endometriosis or ovarian cancer. It is not known how interactions between epigenomically defective stromal cells and the mutated genes in epithelial cells contribute to the pathogenesis of endometriosis. Endometriosis-associated pelvic pain is managed by suppression of ovulatory menses and estrogen production, cyclooxygenase inhibitors, and surgical removal of pelvic lesions, and in vitro fertilization is frequently used to overcome infertility. Although novel targeted treatments are becoming available, as endometriosis pathophysiology is better understood, preventive approaches such as long-term ovulation suppression may play a critical role in the future.

Metabolomic profile as a noninvasive adjunct tool for the diagnosis of Grades III and IV endometriosis-related infertility

The aim of the present case-control study was to develop a noninvasive adjuvant tool for the diagnosis of endometriosis. Serum samples from 100 patients undergoing intracytoplasmic sperm injection were split into two groups according to the cause of infertility: an endometriosis group (n = 50), consisting of samples derived from patients with Grade III and IV endometriosis, and a control group (n = 50), comprising samples derived from patients with isolated male factor infertility. The metabolomic profile of each sample was obtained, through mass spectrometry. Partial least squares discriminant analysis was able to clearly classify the endometriosis and control groups. Ten potential biomarkers were selected based on their importance for model prediction. These ions were used to build the receiver-operating characteristic curve, which presented an area under the curve of 0.904 (95% confidence interval: 0.796-0.985). To validate the model, 30 other samples from infertile women without any evidence of endometriosis were tested. Considering these ions as possible biomarkers, the model was able to correctly classify 84% of the patients. Finally, a similar prediction potential was observed in the model validated set, when samples from the disease-free group were tested. Serum metabolomics may be useful as a noninvasive adjunct tool for the selection of patients who must undergo laparoscopy for definitive endometriosis diagnosis.

Contralateral ovarian endometrioma recurrence after unilateral salpingo-oophorectomy

Background

The recurrence rate after unilateral salpingo-oophorectomy (USO) for unilateral endometrioma has not been reported. We evaluated the rate of and risk factors for endometrioma recurrence after USO.

Methods

In this retrospective observational study, we enrolled 110 women (age, 35–45 years) who underwent laparoscopic USO (n = 50) or cystectomy (n = 60) for unilateral ovarian endometrioma from January 2010 through December 2012. We compared patients’ characteristics between patients who underwent USO and those who underwent cystectomy. We also compared patients with and without an endometrioma recurrence after USO using univariate and multivariate stepwise logistic regression models to identify recurrence risk factors. Endometrioma recurrence was defined as an ovarian cyst (> 2 cm) with features typical of an endometrioma identified by postoperative transvaginal sonography.

Results

Endometrioma recurred in 8 (16%) patients after USO (mean follow-up, 46.0 ± 12.9 months [range, 15–73]). The post-USO cumulative recurrence rates at 12, 24, 36, and 60 months were 8.0, 10.2, 12.7, and 24.7%, respectively (Kaplan-Meier analysis). In logistic regression analysis, a contralateral side adhesion score ≥ 4 was an independent risk factor for endometrioma recurrence after USO (odds ratio, 19.48, 95% confidence interval, 1.59–237.72). The post-USO cumulative recurrence rates at 12, 24, 36, and 57 months were 19.5, 24.1, 31.0, and 54.0%, respectively, in cases with contralateral side adhesion scores ≥4, and 0.0, 0.0, 0.0, and 5.9%, respectively, in cases with scores < 4 (log-rank test, P = 0.0023).

Conclusions

To our knowledge, this is the first report on the recurrence rate and risk factors associated with recurrence after USO. Endometrioma recurrence rates were 24.7% during the first 5 years after USO. The post-USO recurrence rate increased significantly in cases with contralateral side adhesions. Our findings could improve the planning of USO and patient selection for postoperative hormonal therapy.

MRI versus laparoscopy to diagnose the main causes of chronic pelvic pain in women: a test-accuracy study and economic evaluation

BACKGROUND

Chronic pelvic pain (CPP) symptoms in women are variable and non-specific; establishing a differential diagnosis can be hard. A diagnostic laparoscopy is often performed, although a prior magnetic resonance imaging (MRI) scan may beneficial.

OBJECTIVES

To estimate the accuracy and added value of MRI in making diagnoses of (1) idiopathic CPP and (2) the main gynaecological causes of CPP. To quantify the impact MRI can have on decision-making with respect to triaging for therapeutic laparoscopy and to conduct an economic evaluation.

DESIGN

Comparative test-accuracy study with cost-effectiveness modelling.

SETTING

Twenty-six UK-based hospitals.

PARTICIPANTS

A total of 291 women with CPP.

METHODS

Pre-index information concerning the patient's medical history, previous pelvic examinations and ultrasound scans was collected. Women reported symptoms and quality of life at baseline and 6 months. MRI scans and diagnostic laparoscopy (undertaken and interpreted blind to each other) were the index tests. For each potential cause of CPP, gynaecologists indicated their level of certainty that the condition was causing the pelvic pain. The analysis considered both diagnostic laparoscopy as a reference standard for observing structural gynaecological causes and consensus from a two-stage expert independent panel for ascertaining the cause of CPP. The stage 1 consensus was based on pre-index, laparoscopy and follow-up data; for stage 2, the MRI scan report was also provided. The primary analysis involved calculations of sensitivity and specificity for the presence or absence of each structural gynaecological cause of pain. A decision-analytic model was developed, with a 6-month time horizon. Two strategies, laparoscopy or MRI, were considered and populated with study data.

RESULTS

Using reference standards of laparoscopic and expert panel diagnoses, MRI scans had high specificity but poor sensitivity for observing deep-infiltrating endometriosis, endometrioma, adhesions and ovarian cysts. MRI scans correctly identified 56% [95% confidence interval (CI) 48% to 64%] of women judged to have idiopathic CPP, but missed 46% (95% CI 37% to 55%) of those considered to have a gynaecological structural cause of CPP. MRI added significant value, over and above the pre-index information, in identifying deep-infiltrating endometriosis (p = 0.006) and endometrioma (p = 0.02) as the cause of pain, but not for other gynaecological structural causes or for identifying idiopathic CPP (p = 0.08). Laparoscopy was significantly more accurate than MRI in diagnosing idiopathic CPP (p < 0.0001), superficial peritoneal endometriosis (p < 0.0001), deep-infiltrating endometriosis (p < 0.0001) and endometrioma of the ovary (p = 0.02) as the cause of pelvic pain. The accuracy of laparoscopy appeared to be able to rule in these diagnoses. Using MRI to identify women who require therapeutic laparoscopy would lead to 369 women in a cohort of 1000 receiving laparoscopy unnecessarily, and 136 women who required laparoscopy not receiving it. The economic analysis highlighted the importance of the time horizon, the prevalence of CPP and the cut-off values to inform the sensitivity and specificity of MRI and laparoscopy on the model results. MRI was not found to be a cost-effective diagnostic approach in any scenario.

CONCLUSIONS

MRI was dominated by laparoscopy in differential diagnosis of women presenting to gynaecology clinics with CPP. It did not add value to information already gained from history, examination and ultrasound about idiopathic CPP and various gynaecological conditions.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN13028601.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 22, No. 40. See the NIHR Journals Library website for further project information.

Biological differences between intrinsic and extrinsic adenomyosis with coexisting deep infiltrating endometriosis

RESEARCH QUESTION

Is there a biological difference between intrinsic and extrinsic adenomyosis with coexisting deep infiltrating endometriosis (DIE)?

DESIGN

In this prospective controlled study, biopsy specimens were collected after surgery from 23 women with intrinsic adenomyosis and 10 women with extrinsic adenomyosis with coexisting DIE lesions. Histological evaluation was carried out by immunoreaction to Ber-EP4 (epithelial cell marker) and CD10 (stromal cell marker). Tissue expression of oestrogen and progesterone receptors was analysed by immunohistochemistry. Tissue fibrosis was examined by Masson's trichrome staining with computer-based image analysis of fibrosis in respective samples.

RESULTS

The detection rate of coexistent DIE was significantly higher in women with extrinsic adenomyosis (9/10 [90.0%]) than in women with intrinsic adenomyosis (3/23 [13.0%]; P < 0.001). The pattern of Ber-EP4-stained glands and CD10-stained stromal cells of extrinsic adenomyosis was similar to that of coexistent DIE lesions. In contrast, the pattern of gland and stromal cells was similar to the endometrium in the cases with intrinsic adenomyosis. Unlike extrinsic adenomyosis, progesterone receptor expression was significantly decreased in both gland cells (P < 0.05) and stromal cells (P < 0.05) of intrinsic adenomyosis. Although relatively more fibrosis was seen in biopsy samples of extrinsic adenomyosis and coexistent DIE than in intrinsic adenomyosis and their coexistent DIE, no significant difference was found.

CONCLUSIONS

Extrinsic adenomyosis may be considered as adenomyosis externa based on a close histological and biological relationship between extrinsic adenomyosis and coexistent DIE. Our findings may contribute to the understanding of a possible biological origin of two newly classified intrinsic and extrinsic adenomyosis.

Correlation of LOX‑5 and COX‑2 expression with inflammatory pathology and clinical features of adenomyosis

Adenomyosis is a common benign disease of women of childbearing age. The typical clinical features are prolonged menstruation, menorrhagia and ingravescent dysmenorrhea. In the present study, the severity of dysmenorrhea was assessed using the visual analogue scale system as follows: 0, No pain; 1‑3, minimal pain; 4‑6, moderate pain; and 7‑10, severe pain. Menstrual blood loss was evaluated using the pictorial blood loss assessment chart (PBAC). Menorrhagia was defined as excessive menstrual blood loss >80 ml (PBAC >100) per period. Specimens of eutopic endometrium (EU) and ectopic endometrium (EC) were collected from 20 patients with adenomyosis to evaluate the association between lipoxygenase‑5 (LOX‑5) and cyclooxygenase 2 (COX‑2) and inflammatory pathology and clinical features of adenomyosis. For that purpose, the expression levels of LOX‑5, COX‑2, interleukin (IL)‑6 and IL‑8 in the EU and EC of patients with adenomyosis were determined, and clinical data including dysmenorrhea and menstruation were analyzed. Differences in expression levels of LOX‑5 and COX‑2 were detected, and the correlations between LOX‑5, COX‑2, IL‑6 and IL‑8 in different groups were analyzed. In addition, the correlations between LOX‑5, COX‑2 and clinical features of adenomyosis were investigated. The present study demonstrated that LOX‑5 and COX‑2 are overexpressed in EU and EC, and they have positive correlations with IL‑6 and IL‑8, suggesting that adenomyosis lesions are present in inflammatory pathological conditions. The expression levels of LOX‑5 and COX‑2 exhibited a correlation with dysmenorrhea and menstruation.

Chronic pelvic pain and the role of exploratory laparoscopy as diagnostic and therapeutic tool: a retrospective observational study

Background

Forty percent of exploratory laparoscopies are performed for chronic pelvic pain (CPP). However, a final diagnosis is still unreported in 35% of the patients. We decided to evaluate the identification of pathological lesions and the improvement of painful symptoms in patients with CPP and normal physical examination and imaging and who are scheduled for exploratory laparoscopy. The prospective study was designed in a tertiary referral center for endometriosis. Forty-eight patients complaining of CPP and scheduled for exploratory laparoscopy were included. Pelvic pain intensity was assessed using the visual analogue pain scale (VAS), and at inclusion, negative clinical and imaging assessments were required. During exploratory laparoscopy, the recognized lesions were reported and different surgical treatment options were performed depending on the location of the lesion.

Results

In 98% of the cases, exploratory laparoscopy demonstrated the presence of pelvic anomalies that had not been diagnosed at the time of clinical and imaging examination. After surgery, a significant improvement of CPP has been demonstrated in 24 (59%) patients with VAS < 5 postoperatively.

Conclusions

Exploratory laparoscopy is reasonable in patients complaining of CPP, allowing a final diagnosis in a high percentage of patients and a significant improvement in pain symptom in 59% of the cases. This study was retrospectively registered by our local Ethics Committee on February 7, 2018 (B412201835729).

Near-Infrared Imaging with Indocyanine Green for Detection of Endometriosis Lesions (Gre-Endo Trial): A Pilot Study

STUDY OBJECTIVE

To evaluate near-infrared radiation imaging with intravenous indocyanine green (NIR-ICG) during laparoscopic intervention to identify endometriosis lesions.

DESIGN

A single-center, prospective, single-arm pilot study (Canadian Task Force classification II-2).

SETTING

An academic tertiary care and research center.

PATIENTS

Twenty-seven patients with symptomatic endometriosis were enrolled.

INTERVENTIONS

Patients underwent laparoscopic surgery using a laparoscopic system prototype with NIR-ICG.

MEASUREMENTS AND MAIN RESULTS

A total of 116 suspected endometriosis lesions were removed from 27 patients. One hundred lesions had already been visualized in white light imaging by an expert surgeon; the remaining 16 were detected and removed using NIR-ICG. A total of 111 specimens were positive for endometriosis pathology. Positive predictive value of 95% and 97.8% and negative predictive value of 86.2% and 82.3% were found by white light imaging and NIR-ICG, respectively, with sensitivity of 85.6% and 82% and specificity of 95.2% and 97.9%, respectively.

CONCLUSION

NIR-ICG may be a tool for intraoperative diagnosis, confirmation of visible endometriosis lesions, and a marker for identifying occult endometriosis. Further prospective studies with a larger population sample are warranted to validate these encouraging preliminary results.

Patterns of Bowel Invisible Microscopic Endometriosis Reveal the Goal of Surgery: Removal of Visual Lesions Only

STUDY OBJECTIVE

To document the presence of bowel invisible microscopic endometriosis implants and their relationship with deep endometriosis macronodule infiltrating the bowel.

DESIGN

A series of consecutive patients with deep endometriosis infiltrating the rectum and/or sigmoid colon (Canadian Task Force classification II-2).

SETTINGS

A university referral center.

PATIENTS

Ten patients managed by colorectal resection.

INTERVENTIONS

A microscopic study of endometriotic foci of the bowel involving 3272 microsection slides was established using a unique method of step serial sections using combined transverse and longitudinal macrosection. Two-dimensional reconstruction based on slide scanning highlighted the presence and localization of the deep endometriosis macronodule in contrast with bowel invisible microscopic endometriosis microimplants.

MEASUREMENTS AND MAIN RESULTS

The distance separating the microimplants and the nodule and their histologic characteristics. The mean length of the colorectal specimens was 91 ± 19 mm. The maximum distance between the farthest microimplants was 7.2 cm. The maximum distance from the macroscopic nodule limit to the farthest microimplant was 31 mm. Bowel invisible microscopic endometriosis microimplants presented with similar features independently of the type of spread. They had an active appearance including stroma and glands, were sometimes decidualized, and were free of fibrosis. They were found on the distal/rectal limit of the specimen in 3 patients and on both limits (distal/rectal and proximal/sigmoid colon) in 1 patient.

CONCLUSION

Invisible microscopic endometriosis implants surround the bowel macroscopic endometriosis nodule at variable distances, suggesting that complete surgical microscopic removal may be a challenging goal. These results may help to reconsider the principles and feasibility of the surgical management of bowel endometriosis.

Effect of an 8K ultra-high-definition television system in a case of laparoscopic gynecologic surgery

Various endoscopic devices have been developed for advanced minimally invasive surgery. We recently applied a new 8K ultra-high-definition television system during laparoscopic treatment of endometriosis. The procedure, which is described in detail, stands as the first reported application of an 8K ultra-high-definition system for laparoscopic gynecologic surgery. Comparison is made between depiction of the lesion by the new system and depiction by a full high-definition system. Improved diagnostic accuracy resulted from the increased image resolution, and we believe that this and other advantages will lead to widespread acceptance and further application of 8K ultra-high-definition systems in the field of gynecologic surgery.

Kinase signalling pathways in endometriosis: potential targets for non-hormonal therapeutics

BACKGROUND

Endometriosis, the growth of endometrial tissue outside the uterine cavity, is associated with chronic pelvic pain, subfertility and an increased risk of ovarian cancer. Current treatments include the surgical removal of the lesions or the induction of a hypoestrogenic state. However, a reappearance of the lesion after surgery is common and a hypoestrogenic state is less than optimal for women of reproductive age. Additional approaches are required. Endometriosis lesions exist in a unique microenvironment characterized by increased concentrations of hormones, inflammation, oxidative stress and iron. This environment influences cell survival through the binding of membrane receptors and a subsequent cascading activation of intracellular kinases that stimulate a cellular response. Many of these kinase signalling pathways are constitutively activated in endometriosis. These pathways are being investigated as therapeutic targets in other diseases and thus may also represent a target for endometriosis treatment.

METHODS

To identify relevant English language studies published up to 2015 on kinase signalling pathways in endometriosis, we searched the Pubmed database using the following search terms in various combinations; 'endometriosis', 'inflammation', 'oxidative stress', 'iron', 'kinase', 'NF kappa', 'mTOR', 'MAPK' 'p38', 'JNK', 'ERK' 'estrogen' and progesterone'. Further citing references were identified using the Scopus database and finally current clinical trials were searched on the clinicaltrials.gov trial registry.

RESULTS

The current literature on intracellular kinases activated by the endometriotic environment can be summarized into three main pathways that could be targeted for treatments: the canonical IKKβ/NFκB pathway, the MAPK pathways (ERK1/2, p38 and JNK) and the PI3K/AKT/mTOR pathway. A number of pharmaceutical compounds that target these pathways have been successfully trialled in in vitro and animal models of endometriosis, although they have not yet proceeded to clinical trials. The current generation of kinase inhibitors carry a potential for adverse side effects.

CONCLUSIONS

Kinase signalling pathways represent viable targets for endometriosis treatment. At present, however, further improvements in clinical efficacy and the profile of adverse effects are required before these compounds can be useful for long-term endometriosis treatment. A better understanding of the molecular activity of these kinases, including the specific extracellular compounds that lead to their activation in endometriotic cells specifically should facilitate their improvement and could potentially lead to new, non-hormonal treatments of endometriosis.

Morphologic Features Suggestive of Endometriosis in Nondiagnostic Peritoneal Biopsies

Endometriosis is a common disorder that causes significant morbidity from dysmenorrhea, pelvic pain, and subfertility. Establishment of a definitive diagnosis has important therapeutic implications; however, only approximately 50% of biopsies of laparoscopically suspicious areas provide a diagnosis of endometriosis. Histologic criteria for diagnosis require the presence of endometrial glands or endometrial-type stroma. We hypothesize that other frequently present, but nondiagnostic, histologic features of endometriosis suggest its presence in patients with nondiagnostic peritoneal biopsies. We performed a retrospective clinicopathologic study of morphologic and immunohistochemical features that may improve the histologic diagnosis of endometriosis on laparoscopic peritoneal biopsies. We compared diagnostic (n=88) and nondiagnostic (n=54) peritoneal biopsies from pathologically confirmed endometriosis cases with negative peritoneal biopsies (n=84) from early-stage gynecologic cancer cases. Statistical analysis utilized the Fisher exact test. Multiple morphologic features were significantly increased in nondiagnostic biopsies from patients with endometriosis in comparison with those from negative controls, including foamy macrophages (P=0.0001) and submesothelial stromal clusters (SSCs) (P=0.0008). SSCs ranged from subtle aggregates of spindle cells to nodules of whorled spindle cells with small vessels and extravasated red blood cells resembling stromal endometriosis. Immunohistochemical studies confirmed that ER and CD10-positive SSCs were present in a greater proportion of both nondiagnostic and diagnostic peritoneal biopsies and at a greater number of lesions per biopsy. The overall histologic detection rate of peritoneal biopsies for endometriosis was 62.0%, and inclusion of SSCs with or without foamy macrophages in the diagnostic criteria appreciably increased this rate to between 72.5% and 76.8%. We describe SSCs, which appear to be an early or less developed form of stromal endometriosis, and, when included in the diagnostic criteria, improve the histologic detection rate of endometriosis in peritoneal biopsies.

High-throughput sequencing approach uncovers the miRNome of peritoneal endometriotic lesions and adjacent healthy tissues

Accumulating data have shown the involvement of microRNAs (miRNAs) in endometriosis pathogenesis. In this study, we used a novel approach to determine the endometriotic lesion-specific miRNAs by high-throughput small RNA sequencing of paired samples of peritoneal endometriotic lesions and matched healthy surrounding tissues together with eutopic endometria of the same patients. We found five miRNAs specific to epithelial cells – miR-34c, miR-449a, miR-200a, miR-200b and miR-141 showing significantly higher expression in peritoneal endometriotic lesions compared to healthy peritoneal tissues. We also determined the expression levels of miR-200 family target genes E-cadherin, ZEB1 and ZEB2 and found that the expression level of E-cadherin was significantly higher in endometriotic lesions compared to healthy tissues. Further evaluation verified that studied miRNAs could be used as diagnostic markers for confirming the presence of endometrial cells in endometriotic lesion biopsy samples. Furthermore, we demonstrated that the miRNA profile of peritoneal endometriotic lesion biopsies is largely masked by the surrounding peritoneal tissue, challenging the discovery of an accurate lesion-specific miRNA profile. Taken together, our findings indicate that only particular miRNAs with a significantly higher expression in endometriotic cells can be detected from lesion biopsies, and can serve as diagnostic markers for endometriosis.