The pathophysiology of uterine adenomyosis: an update

Does adenomyosis influence tumor characteristics and survival in endometrioid-type endometrial cancer??

BACKGROUND

The coexistence of adenomyosis and cancer of the endometrium has attracted heightened scrutiny, leading to inquiries regarding their possible interactions and clinical ramifications. This study sought to assess the influence of adenomyosis on tumor features and survival outcomes in patients with endometrioid-type endometrial carcinoma.

MATERIALS AND METHODS

A retrospective cohort analysis was performed on 422 patients who underwent surgical intervention for endometrioid-type endometrial carcinoma. The cohort was categorized into two groups according to the presence or absence of adenomyosis. Clinical and pathological data were gathered and evaluated to compare tumor features and survival outcomes between the two cohorts.

RESULTS

Adenomyosis was present in 144 (34.1%) patients. Patients in the adenomyosis group demonstrated significantly higher gravidity and parity compared to those without adenomyosis. Lymphovascular space invasion was detected in 8.3% of the adenomyosis group compared to 17.6% in the non-adenomyosis group (a 53% reduction, p = 0.010). Similarly, rates of myometrial invasion (81.3% vs. 65.5%, p = 0.001), cervical stromal invasion (9.0% vs. 14.1%, p = 0.005), and lymph node metastasis (4.2% vs. 14.4%, p = 0.001) were significantly lower in patients with adenomyosis. The five-year overall survival rate was 90.8% in the adenomyosis group and 87.1% in the non-adenomyosis group, although this difference was not statistically significant (p = 0.689).

CONCLUSIONS

This study demonstrates that adenomyosis is associated with a significant reduction in aggressive tumor characteristics such as myometrial invasion, lymphovascular space involvement, and lymph node metastasis in patients with endometrioid-type endometrial cancer. These findings emphasize that adenomyosis may be a potential protective factor in endometrial cancer prognosis and should be considered in clinical risk assessment. Prospective studies with larger cohorts are needed to confirm the long-term effects of adenomyosis on survival.

The Involvement of Mitochondrial Dysfunction during the Development of Adenomyosis

The etiology of adenomyosis remains unclear. The association between epithelial-mesenchymal transition (EMT) and mitochondrial dysfunction is involved in fibrotic diseases. Adenomyosis is defined as the existence of endometrial glands and stroma in the myometrium with EMT and ultimate fibrosis. This study was designed to investigate the involvement of mitochondrial dysfunction in fibrotic adenomyosis. Mitochondrial integrity was examined in mouse and human adenomyotic tissues. Control and tamoxifen-treated mice were treated with 3-nitropropionic acid (a mitochondrial dysfunction inducer) and NG-nitro-L-arginine methyl ester (a mitochondrial dysfunction inhibitor), respectively, at postnatal day 21, followed by an evaluation of adenomyosis, EMT, and fibrosis as well as the expression of mitophagy, oxidative stress, and transforming growth factor-β1 (TGF-β1). The gene profiles of adenomyotic uteri were examined at postnatal day 42. Adenomyotic mice exhibited increased development of EMT and fibrosis. Adenomyotic tissues showed consistent mitochondrial destruction with increased fission, mitophagosomes, and lysosomes. Besides, mitophagy, oxidative stress, and TGF-β1 levels were consistently increased. The mitochondrial dysfunction, the development of mitophagy and fibrosis, and TGF-β1 expression were induced by 3-nitropropionic acid in control uteri. In contrast, NG-nitro-L-arginine methyl ester attenuated mitochondrial dysfunction, mitophagy, fibrosis, and TGF-β1 in adenomyotic uteri. Gene profiling demonstrated increased expression of mitochondrial dysfunction-related genes in adenomyotic uteri. This indicates that mitochondrial dysfunction-induced TGF-β1 dysregulation and fibrosis are associated with the development of adenomyosis.

Adenomyosis Patterns on Transvaginal Sonography Could Predict the Obstetrical Outcomes of Fertility-sparing Surgeries: A Retrospective Cohort Study

STUDY OBJECTIVE

To explore the associations between adenomyosis patterns on transvaginal sonography (TVS) and surgical outcomes.

DESIGN

A retrospective cohort study.

SETTING

Peking Union Medical College Hospital, Beijing, China.

PATIENTS

The medical records of 322 patients diagnosed with adenomyosis who underwent open or laparoscopic fertility-sparing surgeries from March 1 to December 31, 2018, were reviewed. Patients were divided into localized (221 patients) and diffuse (101 patients) adenomyosis groups on the basis of TVS findings.

INTERVENTIONS

Detailed epidemiological information, imaging evaluations, surgical reports, and pathological findings were retrospectively collected.

MEASUREMENTS AND MAIN RESULTS

The median postsurgical follow-up period was 52.8 months (range 6-88 months), with 24 patients (7.4%) lost to follow-up by July 1, 2019. The localized and diffuse adenomyosis groups had similar symptom relief and recurrent uterine lesions. Among the 104 patients who attempted pregnancy, 75 patients (72.1%) conceived, with 35 miscarriages (46.7%) and 59 live births (78.7%). For the whole cohort and the localized adenomyosis and diffuse adenomyosis groups, the cumulative 5-year conception rates were 75%, 83% and 60%, respectively; the cumulative 5-year live birth rates were 63%, 79% and 37%, respectively. The adenomyosis patterns found during sonography were the only independent risk factors related to clinical pregnancy and live birth in the Cox regression model. Patients with diffuse adenomyosis had significantly lower rates of conception (HR 0.5, 95% CI 0.3-1.0) and live birth (HR 0.4, 95% CI 0.2-0.8).

CONCLUSION

Adenomyosis patterns (localized versus diffuse) in pretreatment TVS could predict obstetrical outcomes, irrespective of surgical type and uterine size.

CLINICAL REGISTRY

The clinical trial registry name is the Cooperative Adenomyosis Network (CAN); the registration number is NCT03230994 (https://clinicaltrials.gov). This study started on June 30, 2017, and was completed on December 30, 2020.

Decreased expression of Syndecan- 1 (CD138) in the endometrium of adenomyosis patients suggests a potential pathogenetic role

INTRODUCTION

Adenomyosis is a special subtype of endometriosis, affecting the myometrium, affecting about 20% of women in the reproductive age period. Clinical symptoms and intensity are diverse and can vary from heavy menstrual bleeding and dysmenorrhea to infertility and repeated pregnancy losses. Thus, patients often present with a long history of illness pending presumptive clinical or surgical diagnosis. A definitive diagnosis of adenomyosis is made upon histopathological examination verifying ectopic endometrial tissue (endometrial glands and/or stroma) within the myometrium, surrounded by hyperplastic and hypertrophic smooth muscles. However, nowadays ultrasonographic and/or MRI signs can precisely detect it as well. The precise etiology and pathogenesis remain unclear. One theory assumes that adenomyosis occurs through metaplastic transformation or migration of stem cell-like cells.

MATERIAL AND METHODS

Our study examined the immunohistochemical expression of the transmembrane proteoglycan Syndecan-1 (CD 138), a multifunctional matrix receptor and signaling co-receptor, in the endometrium of 35 patients (n = 21 with adenomyosis and n = 14 as a control group) in the period 2016-2017.

RESULTS

As a pilot study, we concluded that Syndecan-1 is downregulated in adenomyosis patients compared to the control group, supporting its potential role in the development of adenomyosis. Our study did not find a correlation between the immune-expression of Syndecan-1 and the menstrual cycle phase.

CONCLUSIONS

For clinical significance in relation to our results, the investigated data showed that the downregulation of Syndecan-1 in adenomyotic patients in our study may suggest a role in promoting the invasiveness of endometriotic islands within the myometrium. However, further studies are still needed to understand the mechanistic contribution of Syndecan-1 to the pathogenesis of adenomyosis.

Critical appraisal and narrative review of the literature in IVF/ICSI patients with adenomyosis and endometriosis

Endometriosis and adenomyosis are prevalent causes of infertility, often coexisting in a significant proportion of patients. Although endometriosis typically does not negatively impact assisted reproductive technology (ART) outcomes, the presence of coexisting adenomyosis, mainly non-severe external forms, may slightly influence IVF/ICSI success rates. However, this impact is often minimal and may result in insignificant changes in statistical analyses. Recent studies underscore the critical role of accurate diagnostic techniques, such as ultrasound or MRI, in identifying severe adenomyosis characteristics, including diffuse involvement with junctional zone participation. This precise delineation is reassuring, as it is essential for tailoring assisted reproductive technology (ART) strategies to enhance success rates and reduce the confounding effects of adenomyosis, particularly when it coexists with endometriosis. Strategic approaches, such as ultralong GnRH agonist protocols or freeze-all strategies, may provide advantages in these scenarios. However, the need for extensive research is vital to understanding the complex interactions between endometriosis, adenomyosis, and ART outcomes. This ongoing exploration is particularly important in cases where coexisting adenomyosis might not significantly influence statistical results.

Effects of pretreatment strategies on fertility outcomes in patients with adenomyosis

Adenomyosis is a commonly encountered pathology in women of reproductive age and frequently coexists with infertility. The effect of adenomyosis on fertility, particularly on in vitro fertilisation and intracytoplasmic sperm injection outcomes, is not well understood. Various pretreatment modalities have been used to improve pregnancy rates and live birth outcomes; however, because of a lack of high-quality evidence, there is no clear consensus on the best pretreatment option. This review was conducted through a PubMed search aiming to highlight the relationship between pretreatment and fertility in women with adenomyosis. Medical, ablative surgical, and non-surgical therapies were reviewed. According to the current literature, gonadotropin-releasing hormone agonist therapy and placement of a levonorgestrel intrauterine system are two suitable medical pretreatment strategies that can improve the clinical pregnancy rates of patients with adenomyosis. Surgical ablation of adenomyosis can also be beneficial, although surgical management can be challenging. Non-surgical thermal techniques, including high-intensity focused ultrasound ablation, percutaneous microwave ablation, and radiofrequency ablation, are much less invasive techniques that have shown effectiveness in improving fertility. Although evidence remains limited, all these procedures have demonstrated a favourable safety profile. Further studies are needed to better develop these techniques and demonstrate their effectiveness.

The matrix stiffness is increased in the eutopic endometrium of adenomyosis patients: a study based on atomic force microscopy and histochemistry

Previous ultrasound studies suggest that patients with adenomyosis (AM) exhibit increased uterine cavity stiffness, although direct evidence regarding extracellular matrix (ECM) content and its specific impact on endometrial stiffness remains limited. This study utilized atomic force microscopy to directly measure endometrial stiffness and collagen morphology, enabling a detailed analysis of the endometrium's mechanical properties: through this approach, we established direct evidence of increased endometrial stiffness and fibrosis in patients with AM. Endometrial specimens were also stained with Picrosirius red or Masson's trichrome to quantify fibrosis, and additional analyses assessed α-SMA and Ki-67 expression. Studies indicate that pathological conditions significantly influence the mechanical properties of endometrial tissue. Specifically, adenomyotic endometrial tissue demonstrates increased stiffness, associated with elevated ECM and fibrosis content, whereas normal endometrial samples are softer with lower ECM content. AM appears to alter both the mechanical and histological characteristics of the eutopic endometrium. Higher ECM content may significantly impact endometrial mechanical properties, potentially contributing to AM-associated decidualization defects and fertility challenges.

Eutopic and Ectopic Endometrial Interleukin-17 and Interleukin-17 Receptor Expression at the Endometrial-Myometrial Interface in Women with Adenomyosis: Possible Pathophysiology Implications

Adenomyosis involves the infiltration of endometrial glands and stroma deep into the uterine tissue, causing disruption to the endometrial-myometrial interface (EMI). The role of interleukin-17 (IL-17) has been extensively studied in endometriosis, but its involvement in adenomyosis remains unclear. This study aimed to investigate the expression of IL-17 in eutopic and ectopic endometrium (adenomyosis) of individuals with adenomyosis at the level of EMI. Paired tissues of eutopic endometrium and adenomyoma were collected from 16 premenopausal women undergoing hysterectomy due to adenomyosis. The IL-17 system was demonstrated in paired tissue samples at the level of EMI by the immunochemistry study. Gene expression levels of IL-17A and IL-17 receptor (IL-17R) were assessed through quantitative real-time reverse transcription polymerase chain reaction (RT-PCR). Comparative gene transcript amounts were calculated using the delta-delta Ct method. By immunohistochemical staining, CD4, IL-17A, and IL-17R proteins were detected in both eutopic endometrium and adenomyosis at the level of EMI. IL-17A and IL-17R were expressed mainly in the glandular cells, and the expression of both IL-17A and IL-17R was found to be stronger in adenomyosis than in endometrium. 3-Diaminobenzidine (DAB) staining revealed greater IL-17A expression in adenomyosis compared to eutopic endometrium. Quantitative RT-PCR showed 7.28-fold change of IL-17A and 1.99-fold change of IL-17R, and the fold change level of both IL-17A and IL-17R is significantly higher in adenomyosis (IL-17A: p = 0.047, IL-17R: p = 0.027) versus eutopic endometrium. We found significantly higher IL-17 levels in adenomyosis compared to eutopic endometrium at the level of EMI. The results showed that the IL-17 system may play a role in adenomyosis.

Prevalence, incidence, and treatment trends of adenomyosis in South Korean women for 15 years: A national population-based study

OBJECTIVE

Adenomyosis is associated with female infertility worldwide. With improvements in imaging methods, such as pelvic magnetic resonance imaging, the diagnosis and treatment of adenomyosis have changed. This study aimed to evaluate the overall prevalence, incidence, and treatment trends of adenomyosis in South Korea using data from the Korean National Health Insurance Service Database (NHIS).

METHODS

Data were collected from the Korean NHIS, a population-based complete enumeration database. A total of 678 641 women aged 11-55 years diagnosed with adenomyosis (N80.0 ICD-10 code) from the database from 2002 to 2016 were enrolled. After applying a one-year look-back method, 629 592 patients were analyzed to estimate the prevalence, incidence, and treatment trends of adenomyosis.

RESULTS

The overall prevalence during the study period was 3.86 per 1000 people. The prevalence of adenomyosis has increased from 1.42 per 1000 individuals in 2002 to 7.50 per 1000 individuals in 2016. The crude annual incidence rate of adenomyosis was 1.62 per 1000 people in 2003, which increased to 4.12 per 1000 people in 2016. In addition, the proportion of uterus-preserving surgeries in adenomyosis treatments has increased from 7.51% to 21.29% over 15 years.

CONCLUSION

The prevalence and incidence of adenomyosis in South Korea increased between 2002 and 2016. Furthermore, the proportion of uterus-preserving surgeries and progestin prescriptions for adenomyosis treatment has increased. We expect that our findings will raise awareness of the necessity for fertility preservation through earlier diagnosis and proper management of patients with adenomyosis.

Reduced fertility in an adenomyosis mouse model is associated with an altered immune profile in the uterus during the implantation period

STUDY QUESTION

Does a reduction in fertility and/or systemic immune cell change occur during the early implantation period in a mouse model of adenomyosis?

SUMMARY ANSWER

A reduction in fertility was observed in mice with adenomyosis, coinciding with local and systemic immune changes observed during the implantation period.

WHAT IS KNOWN ALREADY

Adenomyosis is a pathology responsible for impaired fertility in humans, with a still unclear pathophysiology. One hypothesis is that changes in immune cells observed in adenomyosis-affected uteri may alter fertility, notably the physiological immune environment necessary for successful implantation and a healthy pregnancy.

STUDY DESIGN, SIZE, DURATION

Randomly selected CD-1 female neonatal pups were orally dosed by administration of tamoxifen to induce adenomyosis (TAM group), while others received solvent only (control group). From 6 weeks of life, CD-1 mice of both groups were mated to study impaired fertility and related local and/or systemic immune cell changes during the early implantation period.

PARTICIPANTS/MATERIALS, SETTINGS, METHODS

To evaluate fertility and pregnancy outcomes, ultrasound imaging was performed at E (embryonic day) 7.5 and E11.5 to count the number of gestational sacs and the number of resorptions in eight mice of the TAM group and 16 mice of the control group. The mice were sacrificed at E18.5, and morphometric, functional (quantitative reverse transcription PCR; RT-qPCR), and histological analyses were performed on the placentas. To identify local and/or systemic immune changes during the early implantation period, 8 mice of the TAM group and 12 mice of the control group were sacrificed at E4.5. Uterine horns and spleens were collected for flow cytometry and RT-qPCR analyses to study the immune cell populations. To investigate the profile of the cytokines secreted during the early implantation period at the systemic level, supernatants from stimulated spleen cells were analyzed by multiplex immunoassay analysis.

MAIN RESULTS AND THE ROLE OF CHANCE

By ultrasound imaging, we observed a lower number of implantation sites (P < 0.005) and a higher number of resorptions (P < 0.001) in the TAM group, leading to smaller litters (average number of fetuses per litter: 1.00 [0.00; 5.25] in the TAM group versus 12.00 [9.50; 13.75] in the control group (P < 0.001). Histological and morphometric analyses of the placentas at E18.5 showed a higher junctional/labyrinthine area ratio in the TAM group (P = 0.005). The expression levels of genes that play a role in vascularization and placental growth (Vegf (P < 0.001), Plgf (P < 0.005), Pecam (P < 0.0001), and Igf2 (P = 0.002)) were reduced in the TAM group. In the TAM group, the percentages of macrophages, natural killer (NK) cells, and dendritic cells (DC) were significantly decreased in the uterus around the implantation period. However, the number of M1 macrophages was increased. Both macrophages and DC had an increased activation profile (higher expression of MCHII, P = 0.012; CD80, P = 0.015; CCR7, P = 0.043 for macrophages, and higher expression of CD206, P = 0.018; CXCR4, P = 0.010; CCR7, P = 0.006, MCHII, P = 0.010; and CD80, P = 0.012 for DC). In spleen, an increase in the activation of macrophages (CCR7, P = 0.002; MCHII, P = 0.001; and CD80, P = 0.034) and DC was observed in the TAM group (CCR7, P = 0.001; MCHII, P = 0.001; Ly6C, P = 0.015). In the uteri and the spleen, we observed increased percentages of CD4+ T lymphocytes (P = 0.0237 and P = 0.0136, respectively) in the TAM group and, in the uteri, an increased number of regulatory T cells (P = 0.036) compared with the controls.

LARGE SCALE DATA

Not applicable.

LIMITATIONS, REASONS FOR CAUTION

This study is limited by the use of an animal model and the lack of intervention.

WIDER IMPLICATIONS OF THE FINDINGS

These data support involvement of innate and adaptive immune cells in the implantation failure and the increased rate of resorption observed in the mouse model of adenomyosis. This substantiates the need for additional research in this domain, with the goal of addressing fertility challenges in women affected by this condition.

STUDY FUNDING/COMPETING INTEREST(S)

None.

Are Adenomyosis and Endometriosis Phenotypes of the Same Disease Process?

In recent literature reviews, we concluded that the possibility that endometrial molecular aberrations are the sole or a necessary determinant of endometriosis and the Tissue Injury and Repair (TIAR) theory are yet to be convincingly proven. Here, we critically examine the theory that adenomyosis and endometriosis represent different phenotypes of a single disease. A common etiopathology for adenomyosis and endometriosis has been suggested because both conditions entail the presence of endometrial tissue at locations other than the lining of the uterus. There are wide differences in reported disease incidence and prevalence and, consequently, in estimates of the coexistence of both conditions. There are some similarities but also differences in their clinical features and predisposing factors. Each condition has a range of subtypes. These differences alone pose the question of whether subtypes of endometriosis and adenomyosis have different etiopathologies, and, in turn, this raises the question of whether they all share a common etiology. It is debatable whether the recognized differences between the eutopic endometrium in adenomyosis and endometriosis compared to those in unaffected women are the cause or the effect of the disease. The finding of common mutations, particularly of KRAS, lend support to the notion of shared predisposing factors, but this alone is insufficient evidence of causation.

Junctional zone thickening: an endo-myometrial unit disorder

Adenomyosis is a disease defined by histopathology, mostly of hysterectomy specimens, and classification is challenged by the disagreement of the histologic definition. With the introduction of Magnetic Resonance Imaging (MRI) and two- and three-dimensional ultrasound, the diagnosis of adenomyosis became a clinical entity. In MRI and US, adenomyosis ranges from thickening of the inner myometrium or junctional zone to nodular, cystic, or diffuse lesions involving the entire uterine wall, up to a well-circumscribed adenomyoma or a polypoid adenomyoma. The absence of an accepted classification and the vague and inconsistent terminology hamper basic and clinical research. The sub-endometrial halo seen at US and MRI is a distinct entity, differing from the outer myometrium by its increased nuclear density and vascular structure. The endometrium and the sub-endometrial muscularis or archimetra are of Müllarian origin, while the outer myometrium is non-Mullerian mesenchymal. The junctional zone (JZ) is important for uterine contractions, conception, implantation, and placentation. Thickening of the JZ can be considered inner myometrium adenomyosis, with or without endometrial invasion. Changes in the JZ should be considered a different entity than myometrial clinically associated with impaired conception, implantation, abnormal uterine bleeding, pelvic pain and obstetrical outcome. Pathology of the basal endometrium and JZ is a separate entity and should be identified as an endo-myometrial unit disorder (EMUD).

Effect of coexisting adenomyosis on tumour characteristics and prognosis of endometrial cancer: A systematic review and meta-analysis

To compare clinicopathological features and survival outcomes in patients with endometrial cancer, with and without associated adenomyosis. PubMed, Embase and Scopus databases were systematically searched for relevant observational studies. The pooled effect sizes were reported as either hazards ratio (HR) for survival-related outcomes or as odds ratio (OR) for other categorical outcomes. Weighted mean difference (WMD) was reported for continuous outcomes. All the analyses used the random effects model. A total of 21 studies (N = 46,420) were included. Compared to endometrial cancer patients without adenomyosis, patients with associated adenomyosis had improved overall 5-year survival (OS) (HR 0.62, 95% CI: 0.50, 0.79) and disease-free survival (DFS) (HR 0.60, 95% CI: 0.44, 0.82). Disease-specific survival was statistically similar in patients with and without adenomyosis (HR 0.60, 95% CI: 0.35, 1.05). Among patients with adenomyosis, the risk of having an advanced tumour grade (Grade 2 or 3) was lower (OR 0.51, 95% CI: 0.42, 0.62) and a risk of having International Federation of Gynaecology and Obstetrics (FIGO) stage I or II was higher (OR 2.23, 95% CI: 1.65, 3.01). Patients with adenomyosis had lower risk of tumour invasion of adnexa, cervical stromal invasion, deep myometrial involvement (DMI), lympho-vascular space invasion (LVSI) and peritoneal invasion. Presence of adenomyosis in patients with endometrial cancer is associated with favourable tumour characteristics and may improve the survival.

Single-Cell Profiling Uncovers the Roles of Endometrial Fibrosis and Microenvironmental Changes in Adenomyosis

Purpose

Adenomyosis (AM) is a common benign uterine disorder that has deleterious effects on women's health. However, the pathogenesis of AM is not clearly understood. We aimed to investigate the pathophysiological changes and molecular mechanism in AM.

Methods

Single-cell RNA sequencing (scRNA-seq) was employed to construct a transcriptomic atlas of various cell subsets from the ectopic endometrium (EC) and eutopic endometrium (EM) of one AM patient and evaluate differential expression. The Cell Ranger software pipeline (version 4.0.0) was applied to conduct sample demultiplexing, barcode processing and mapping reads to the reference genome (human GRCh38). Different cell types were classified with markers with the "FindAllMarkers" function, and differential gene expression analysis was performed with Seurat software in R. The findings were confirmed by Reverse Transcription Real-Time PCR using samples from three AM patients.

Results

We identified nine cell types: endothelial cells, epithelial cells, myoepithelial cells, smooth muscle cells, fibroblasts, lymphocytes, mast cells, macrophages and unknown cells. A number of differentially expressed genes, including CLO4A1, MMP1, TPM2 and CXCL8, were identified from all cell types. Functional enrichment showed that aberrant gene expression in fibroblasts and immune cells was related to fibrosis-associated terms, such as extracellular matrix dysregulation, focal adhesion and the PI3K-Akt signaling pathway. We also identified fibroblast subtypes and determined a potential developmental trajectory related to AM. In addition, we identified increased cell-cell communication patterns in EC, highlighting the imbalanced microenvironment in AM progression.

Conclusion

Our results support the theory of endometrial-myometrial interface disruption for AM, and repeated tissue injury and repair could lead to increased fibrosis in the endometrium. Therefore, the present study reveals the association between fibrosis, the microenvironment, and AM pathogenesis. This study provides insight into the molecular mechanisms regulating AM progression.

Adenomyosis: single-cell transcriptomic analysis reveals a paracrine mesenchymal-epithelial interaction involving the WNT/SFRP pathway

OBJECTIVE

To assess the cellular and molecular landscape of adenomyosis.

DESIGN

Single-cell analysis of genome-wide messenger RNA (mRNA) expression (single-cell RNA sequencing) of matched tissues of endometrium, adenomyosis, and myometrium using relatively large numbers of viable cells.

SETTING

Not applicable.

PATIENT(S)

Patients (n = 3, age range 40-44 years) undergoing hysterectomy for diffuse adenomyosis.

MAIN OUTCOME MEASURE(S)

Definition of the molecular landscape of matched adenomyotic, endometrial and myometrial tissues from the same uterus using single-cell RNA sequencing and comparison of distinct cell types in these tissues to identify disease-specific cell populations, abnormal gene expression and pathway activation, and mesenchymal-epithelial interactions.

RESULT(S)

The largest cell population in the endometrium was composed of closely clustered fibroblast groups, which comprise 36% of all cells and seem to originate from pericyte progenitors differentiating to estrogen/progesterone receptor-expressing endometrial stromal- cells. In contrast, the entire fibroblast population in adenomyosis comprised a larger (50%) portion of all cells and was not linked to any pericyte progenitors. Adenomyotic fibroblasts eventually differentiate into extracellular matrix protein-expressing fibroblasts and smooth muscle cells. Hierarchical clustering of mRNA expression revealed a unique adenomyotic fibroblast population that clustered transcriptomically with endometrial fibroblasts, suggestive of an endometrial stromal cell population serving as progenitors of adenomyosis. Four other adenomyotic fibroblast clusters with disease-specific transcriptomes were distinct from those of endometrial or myometrial fibroblasts. The mRNA levels of the natural WNT inhibitors, named, secreted frizzled-related proteins 1, 2, and 4, were higher in these 4 adenomyotic fibroblast clusters than in endometrial fibroblast clusters. Moreover, we found that multiple WNTs, which originate from fibroblasts and target ciliated and unciliated epithelial cells and endothelial cells, constitute a critical paracrine signaling network in adenomyotic tissue. Compared with endometrial tissue, unciliated and ciliated epithelial cells in adenomyosis comprised a significantly smaller portion of this tissue and exhibited molecular evidence of progesterone resistance and diminished regulation of estrogen signaling.

CONCLUSION(S)

We found a high degree of heterogeneity in fibroblast-like cells in the adenomyotic uterus. The WNT signaling involving differential expression of secreted frizzled-related proteins, which act as decoy receptors for WNTs, in adenomyotic fibroblasts may have a key role in the pathophysiology of this disease.

Comparison of the treatment efficacies of HIFU, HIFU combined with GnRH-a, and HIFU combined with GnRH-a and LNG-IUS for adenomyosis: A systematic review and meta-analysis

To compare the treatment efficacies of high-intensity focused ultrasound (HIFU), HIFU combined with gonadotrophin-releasing hormone agonist (GnRH-a), and HIFU combined with GnRH-a and levonorgestrel-releasing intrauterine system (LNG-IUS) for adenomyosis. We conducted a literature search in SCIENCE DIRECT, COCHRANE LIBRARY, WILLEY ONLINE LIBRARY, PUBMED, and TAYLOR FRANCIS. A total of 471 articles identified, 12 were included in a systematic review, and 11 of them deemed quantitively eligible included in the meta-analysis. The efficacies of the three treatment regimens were assessed using the dysmenorrhea and menstrual scores at 3, 6, 12, 24 months. Of the three regimens, HIFU combined with GnRH-a and LNG-IUS provides the best outcome. On dysmenorrhea score at 6 months there was significantly different higher heterogeneity with P < 0.00001 (I² = 100% WMD 21.44 [6.34, 36.53]) with statistical significance P = 0.005. At 12 months there was significantly different higher heterogeneity P < 0.00001 (I² = 100% WMD 23.47 [6.00, 40.94]) with statistically significant P < 0.008. At 24 months there was significantly different higher heterogeneity P < 0.0005 (I² = 92% WMD 6.05 [4.81, 7.30]) with statistical significance P < 0.00001. HIFU combined with GnRH-a and LNG-IUS on menstrual score at 3 months was significantly different higher heterogeneity with P < 0.00001 (I² = 100% WMD 56.23 [16.01, 96.45]) with statistical significance P = 0.006. At 6 months there was significantly different higher heterogeneity P < 0.00001 (I² = 99% WMD 93.86 [64.15, 123.57]) with statistical significance P < 0.00001. At 12 months there was significantly different higher heterogeneity P < 0.00001 (I² = 99% WMD 97.13 [67.81, 126.46]) with statistical significance P < 0.00001 compared to treatments with only HIFU and HIFU combined with GnRH-a. HIFU combined with GnRH-a and LNG-IUS treatment is more effective than only HIFU monotherapy and HIFU combined with GnRH-a.

MRI of Adenomyosis: Where Are We Today?

Purpose of Review: The purpose of this review is to (i) summarize the current literature regarding the role of magnetic resonance imaging (MRI) in diagnosing adenomyosis, (ii) examine how to integrate MRI phenotypes with clinical symptomatology and histological findings, (iii) review recent advances including proposed MRI classifications, (iv) discuss challenges and pitfalls of diagnosing adenomyosis, and (v) outline the future role of MRI in promoting a better understanding of the pathogenesis, diagnosis, and treatment options for patients with uterine adenomyosis. Recent Findings: Recent advances and the widespread use of MRI have provided new insights into adenomyosis and the range of imaging phenotypes encountered in this disorder. Summary: Direct and indirect MRI features allow for accurate non-invasive diagnosis of adenomyosis. Adenomyosis is a complex and poorly understood disorder with variable MRI phenotypes that may be correlated with different pathogeneses, clinical presentations, and patient outcomes. MRI is useful for the assessment of the extent of findings, to evaluate for concomitant gynecological conditions, and potentially can help with the selection and implementation of therapeutic options. Nevertheless, important gaps in knowledge remain. This is in part due to the lack of standardized criteria for reporting resulting in heterogeneous and conflicting data in the literature. Thus, there is an urgent need for a unified MRI reporting system incorporating standardized terminology for diagnosing adenomyosis and defining the various phenotypes.

Altered Expression of Interleukin-18 System mRNA at the Level of Endometrial Myometrial Interface in Women with Adenomyosis

Adenomyosis is a uterine pathology characterized by a deep invasion of endometrial glands and stroma, disrupting the endometrial−myometrial interface (EMI). Interleukin-18 (IL-18) system is a dominant cytokine involved in the menstrual cycle of human endometrium. IL-18 may play a defensive role against maternal immune response in the uterine cavity. The present study was designed to determine IL-18-mediated immune response at the level of EMI. We uncovered that mRNA of IL-18 system, including IL-18, IL-18 receptor (IL-18R), and its antagonist, IL-18 binding protein (IL-18BP), expressed in eutopic, ectopic endometrium, and corresponding myometrium in patients with adenomyosis. IL-18 system was demonstrated in paired tissue samples by immunochemistry and immunofluorescence study. According to RT-PCR with CT value quantification and 2−∆∆Ct method, a significant down-regulation of IL-18BP in corresponding myometrium in comparison to eutopic endometrium (p < 0.05) indicates that the IL-18 system acts as a local immune modulator at the level of EMI and regulating cytokine networks in the pathogenesis of adenomyosis. Furthermore, an increased IL-18 antagonist to agonist ratio was noted in ectopic endometrium compared with corresponding myometrium. We suggest that altered IL-18 system expression contributes to immunological dysfunction and junctional zone disturbance in women with adenomyosis.

Cracking the enigma of adenomyosis: an update on its pathogenesis and pathophysiology

In brief

Traditionally viewed as enigmatic and elusive, adenomyosis is a fairly common gynecological disease but is under-recognized and under-researched. This review summarizes the latest development on the pathogenesis and pathophysiology of adenomyosis, which have important implications for imaging diagnosis of the disease and for the development of non-hormonal therapeutics.

Abstract

Traditionally considered as an enigmatic disease, adenomyosis is a uterine disease that affects many women of reproductive age and is a contributing factor for pelvic pain, heavy menstrual bleeding (HMB), and subfertility. In this review, the new development in the pathogenesis and pathophysiology of adenomyosis has been summarized, along with their clinical implications. After reviewing the progress in our understanding of the pathogenesis and describing the prevailing theories, in conjunction with their deficiencies, a new hypothesis, called endometrial-myometrial interface disruption (EMID), which is backed by extensive epidemiologic data and demonstrated by a mouse model, is reviewed, along with recent data implicating the role of Schwann cells in the EMI area in the genesis of adenomyosis. Additionally, the natural history of adenomyotic lesions is elaborated and underscores that, in essence, adenomyotic lesions are fundamentally wounds undergoing repeated tissue injury and repair (ReTIAR), which progress to fibrosis through epithelial-mesenchymal transition, fibroblast-to-myofibroblast transdifferentiation, and smooth muscle metaplasia. Increasing lesional fibrosis propagates into the neighboring EMI and endometrium. The increased endometrial fibrosis, with ensuing greater tissue stiffness, results in attenuated prostaglandin E2, hypoxia signaling and glycolysis, impairing endometrial repair and causing HMB. Compared with adenomyosis-associated HMB, the mechanisms underlying adenomyosis-associated pain are less understood but presumably involve increased uterine contractility, hyperinnervation, increased lesional production of pain mediators, and central sensitization. Viewed through the prism of ReTIAR, a new imaging technique can be used to diagnose adenomyosis more accurately and informatively and possibly help to choose the best treatment modality.

The Effect of Uterine Adenomyosis on IVF Outcomes: a Systematic Review and Meta-analysis

To investigate the impact of uterine adenomyosis on in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) clinical outcomes and also to evaluate the impact of gonadotropin-releasing hormone agonist (GnRHa) and surgical treatments. Infertile women with adenomyosis undergoing conventional IVF or ICSI were compared with women without adenomyosis. Fertility outcomes were evaluated in two patients with adenomyosis untreated and treated surgically or medically therapy. The review protocol was registered in PROSPERO (CRD42020214586). We consider the live birth rate (LBR) as the primary outcome. The analysis showed that women with adenomyosis had lower LBR (OR 0.59, 95% CI 0.37-0.92, p = 0.02), clinical pregnancy rate (OR 0.66, 95% CI 0.48-0.90), and ongoing pregnancy rate (OR 0.43, 95% CI 0.21-0.88) compared to those without adenomyosis, and miscarriage rate was higher in women with adenomyosis (OR 2.11, 95% CI 1.33-3.33). Surgical treatment increases natural conception in women with adenomyosis although the paucity of data (only two studies), and conversely, treatment with GnRHa does not increase the IVF outcomes. Women with adenomyosis have decreased IVF clinical outcomes. Pretreatment with the use of long-term GnRHa could not be beneficial, even though only three studies were included in the meta-analysis. The major part of the studies has not divided focal and diffuse adenomyosis, and this represents a relevant source of bias: studies conducted with standardized diagnostic criteria for adenomyosis are still needed to determine if the different clinical presentations of such condition could compromise IVF outcomes.

Transcriptomic analysis supports collective endometrial cell migration in the pathogenesis of adenomyosis

RESEARCH QUESTION

Adenomyosis is a common uterine disorder of uncertain causes. Can transcriptomic analyses of the endometrium and myometrium reveal potential mechanisms underlying adenomyosis pathogenesis?

DESIGN

Transcriptomic profiles of eutopic endometrium and myometrium from women with and without diffuse adenomyosis and with symptomatic FIGO type 2-5 fibroids in the proliferative phase of the menstrual cycle were assessed using RNA sequencing and bioinformatic analysis. Differentially expressed genes (DEG) and potential pathways were validated by quantitative reverse transcription polymerase chain reaction, immunoblotting and Masson staining, using additional clinical samples.

RESULTS

Top biological processes in the endometrium of women with versus without adenomyosis, enriched from DEG, comprised inflammation, extracellular matrix (ECM) organization, collagen degradation and hyaluronan synthesis, which are key in cell migration and cell movement. Top biological processes enriched from DEG in the myometrium of women with versus without adenomyosis revealed ECM organization dysfunction, abnormal sensory pain perception and gamma aminobutyric acid (GABA) synaptic transmission. Dysregulation of prolactin signalling was also enriched in eutopic endometrium and in the myometrium of women with adenomyosis.

CONCLUSIONS

Overall, our results support the invasive endometrium theory in the pathogenesis of adenomyosis, in which inflammation induces ECM remodelling resulting in a track for subsequent endometrial collective cell migration and onset of adenomyosis. Moreover, abnormal myometrial GABA synaptic transmission may contribute to dysmenorrhoea in women with adenomyosis and is a possible target for novel therapeutic development. Prolactin signalling abnormalities may serve as another opportunity for therapeutic intervention.

Increased Angiogenesis and Lymphangiogenesis in Adenomyosis Visualized by Multiplex Immunohistochemistry

There is evidence for increased angiogenesis in the (ectopic) endometrium of adenomyosis patients under the influence of vascular endothelial growth factor (VEGF). VEGF stimulates both angiogenesis and lymph-angiogenesis. However, information on lymph vessels in the (ectopic) endometrium of adenomyosis patients is lacking. In this retrospective matched case-control study, multiplex immunohistochemistry was performed on thirty-eight paraffin embedded specimens from premenopausal women who had undergone a hysterectomy at the Amsterdam UMC between 2001 and 2018 to investigate the evidence for (lymph) angiogenesis in the (ectopic) endometrium or myometrium of patients with adenomyosis versus controls with unrelated pathologies. Baseline characteristics of both groups were comparable. In the proliferative phase, the blood and lymph vessel densities were, respectively, higher in the ectopic and eutopic endometrium of patients with adenomyosis than in the endometrium of controls. The relative number of blood vessels without α-smooth muscle actinin (α SMA) was higher in the eutopic and ectopic endometrium of adenomyosis patients versus controls. The level of VEGF staining intensity was highest in the myometrium but did not differ between patients with adenomyosis or controls. The results indicate increased angiogenesis and lymphangiogenesis in the (ectopic) endometrium affected by adenomyosis. The clinical relevance of our findings should be confirmed in prospective clinical studies.

Estrogen-increased SGK1 Promotes Endometrial Stromal Cell Invasion in Adenomyosis by Regulating with LPAR2

Adenomyosis is an estrogen-dependent gynecological disorder. The abnormal migration and invasion of the eutopic endometrium is thought to be the primary role in the pathogenesis of adenomyosis. However, the exact underlying mechanism remains unclear. This study investigated involvement of serum and glucocorticoid-regulated kinase 1 (SGK1) in the pathogenesis of adenomyosis. The SGK1 expression level was higher in the eutopic endometrium of adenomyosis. Upregulation of SGK1 can promote the migration, invasion of human stromal endometrial cells (HESC). Through RNA sequencing and other technical methods, we found that SGK1 regulates the expression of the important downstream molecule Lysophosphatidic acid receptor 2 (LPAR2), and ultimately regulates the expression level of functional proteins such as matrix metalloproteinase 2 and matrix metalloproteinase 9, which are related to migration and invasion. Then, we found that 17β-estradiol (E₂) upregulated the expression of SGK1 in endometrial cells in a dose-dependent manner. Furthermore, SGK1 shRNA significantly suppressed the migration and invasion induced by E₂ in endometrial cells, as well as the related factors. Our study revealed the possible role of SGK1 in the migration and invasion in the development of adenomyosis.

Uterine bleeding: how understanding endometrial physiology underpins menstrual health

Menstruation is a physiological process that is typically uncomplicated. However, up to one third of women globally will be affected by abnormal uterine bleeding (AUB) at some point in their reproductive years. Menstruation (that is, endometrial shedding) is a fine balance between proliferation, decidualization, inflammation, hypoxia, apoptosis, haemostasis, vasoconstriction and, finally, repair and regeneration. An imbalance in any one of these processes can lead to the abnormal endometrial phenotype of AUB. Poor menstrual health has a negative impact on a person's physical, mental, social, emotional and financial well-being. On a global scale, iron deficiency and iron deficiency anaemia are closely linked with AUB, and are often under-reported and under-recognized. The International Federation of Gynecology and Obstetrics have produced standardized terminology and a classification system for the causes of AUB. This standardization will facilitate future research endeavours, diagnosis and clinical management. In a field where no new medications have been developed for over 20 years, emerging technologies are paving the way for a deeper understanding of the biology of the endometrium in health and disease, as well as opening up novel diagnostic and management avenues.

Evaluation of high intensity focused ultrasound treatment for different types of adenomyosis based on magnetic resonance imaging classification

OBJECTIVE

To evaluate the mid-term symptom improvement of patients with different types of adenomyosis based on magnetic resonance imaging (MRI) classification after ultrasound-guided high intensity focused ultrasound (USgHIFU) treatment.

MATERIALS AND METHODS

A total of 321 patients with adenomyosis who underwent HIFU and completed 18-month follow-up were retrospectively reviewed. Based on the relationship between the adenomyotic lesion and the uterine structural components on T2-weighted imaging (T2WI), adenomyotic lesions were classified as internal, external, full thickness and intramural adenomyosis. Based on the extent of the myometrial involvement, these lesions were further subclassified as asymmetric and symmetric adenomyosis.

RESULTS

All patients completed HIFU ablation in one session. The range of median menstrual pain score in patients with asymmetric internal, symmetric internal, asymmetric external, asymmetric full thickness, symmetric full thickness, and intramural adenomyosis was between 6 and 8 points before HIFU, the median menstrual pain score decreased to 2-4 points 18-month post-HIFU (p < .005). The menstrual pain relief rate was 68.3%, 62.1%, 54.7%, 64.1%, 60%, and 100%, respectively. The median menstrual blood volume score range was between 2 and 4 points in the different groups of patients before HIFU, it decreased to 1-3 points 18-month after HIFU with a relief rate of 68.3%, 51.6%, 51.0%, 55.5%, 57.2%, and 100%, respectively. No serious complication occurred in any of these patients.

CONCLUSIONS

Based on our results, USgHIFU is safe and effective in the treatment of patients with different subtypes of adenomyosis with mid-term sustained improvement in symptoms of menstrual pain and menstrual blood volume.

Association between the occurrence of adenomyosis and the clinical outcomes of vaginal repair of cesarean section scar defects: an observational study

Background

To examine the correlation between the occurrence of adenomyosis and the outcome of vaginal repair of cesarean section scar defects (CSDs).

Methods

A total of 278 women with CSD were enrolled in this retrospective observational cohort study at the Shanghai First Maternity & Infant Hospital between January 2013 and August 2017. Patients were divided into two groups according to preoperative magnetic resonance imaging (MRI) findings: the adenomyosis group and the non-adenomyosis group. They all underwent vaginal excision and suturing of CSDs and were required to undergo examinations 3 and 6 months after surgery. Preoperative and postoperative clinical information was collected. Optimal healing was defined as a duration of menstruation of no more than 7 days and a thickness of the residual myometrium (TRM) of no less than 5.8 mm after vaginal repair.

Results

Before vaginal repair, for patients in the adenomyosis group, the mean duration of menstruation was longer and TRM was significantly thinner than those in patients in the non-adenomyosis group (p < 0.05). The TRM and duration of menstruation 3 and 6 months after surgery were significantly improved in both groups (p < 0.05). There were more patients with optimal healing in the non-adenomyosis group than in the adenomyosis group (44.7% vs. 30.0%; p < 0.05). Furthermore, 59.3% (32/54) of the women tried to conceive after vaginal repair. The pregnancy rates of women with and without adenomyosis were 66.7% (8/12) and 61.9% (26/42), respectively. The duration of menstruation decreased significantly from 13.4 ± 3.3 days before vaginal repair to 7.6 ± 2.3 days after vaginal repair in 25 patients (p < 0.001). The TRM increased significantly from 2.3 ± 0.8 mm before vaginal repair to 7.6 ± 2.9 mm after vaginal repair (p < 0.001).

Conclusions

Vaginal repair reduced postmenstrual spotting and may have improved fertility in patients with CSDs. Patients with adenomyosis are more likely to have suboptimal menstruation and suboptimal healing of CSDs. Adenomyosis might be an adverse factor in the repair of uterine incisions.

Adenomyosis in a uterine horn of a patient with Mayer-Rokitansky-Kuster-Hauser syndrome

A 37-year-old woman with a previous diagnosis of Mayer-Rokitansky-Kuster-Hauser syndrome at 18 years of age was referred from a primary healthcare physician to a gynaecology appointment in our centre. She presented with a 2-year worsening pelvic pain and dyspareunia, symptoms that were previously absent and, at the time, with inadequate relief with oral analgesia. Physical examination showed absent uterine cervix and hypoplastic superior vagina. Transvaginal ultrasound and MRI suggested the presence of an hypoplasic uterus in left rotation. Laparoscopically, two asymmetric rudimentary horns were found, united by a fibrous central band, with an enlarged and congestive left horn. The three structures were removed as a whole. Histopathological examination reported the presence of multiple adenomyotic foci along the full thickness of the left rudimentary horn. The patient had an uneventful postoperative recovery and full remission of her symptoms.

Mouse Cre drivers: tools for studying disorders of the human female neuroendocrine-reproductive axis†

Benign disorders of the human female reproductive system, such primary ovarian insufficiency and polycystic ovary syndrome are associated with infertility and recurrent miscarriage, as well as increased risk of adverse health outcomes, including cardiovascular disease and type 2 diabetes. For many of these conditions, the contributing molecular and cellular processes are poorly understood. The overarching similarities between mice and humans have rendered mouse models irreplaceable in understanding normal physiology and elucidating pathological processes that underlie disorders of the female reproductive system. The utilization of Cre-LoxP recombination technology, which allows for spatial and temporal control of gene expression, has identified the role of numerous genes in development of the female reproductive system and in processes, such as ovulation and endometrial decidualization, that are required for the establishment and maintenance of pregnancy in mammals. In this comprehensive review, we provide a detailed overview of Cre drivers with activity in the neuroendocrine-reproductive axis that have been used to study disruptions in key intracellular signaling pathways. We first summarize normal development of the hypothalamus, pituitary, ovary, and uterus, highlighting similarities and differences between mice and humans. We then describe human conditions resulting from abnormal development and/or function of the organ. Finally, we describe loss-of-function models for each Cre driver that elegantly recapitulate some key features of the human condition and are associated with impaired fertility. The examples we provide illustrate use of each Cre driver as a tool for elucidating genetic and molecular underpinnings of reproductive dysfunction.

Classifying Adenomyosis: Progress and Challenges

Classically, the diagnosis of adenomyosis relied on histological examination of uteri following hysterectomy and classifications focused on the depth of endometrial invasion within the myometrium. There remain uncertainties around the cut-off point for the histological diagnosis. Imaging-based diagnosis enables recognition of the condition in women not undergoing surgery and facilitates the assessment of the extent of adenomyosis within the whole uterus, as well as of affections of the uterovesical pouch and of the pouch of Douglas. In this article, we explore the diagnostic uncertainties, the need to produce a classification of the condition and the challenges towards that goal. A distinction should be drawn between disease mapping and a classification that may link histological or image-based features with clinical characteristics, or with pathophysiology. An agreed system for reporting adenomyotic lesions may enable comparisons of research studies and thus contribute towards an informed classification. To this aim, we outline the features of the condition and explore the characteristics that are considered when producing a taxonomy. These include the latest proposal for subdivision of adenomyosis into an internal and an external variant. We also explore the uncertainties linked to classifying involvement of the uterovesical pouch, the pouch of Douglas and lesions in the outer myometrium. The limitations of currently available evidence suggest that agreement on a hypothesis to underpin a classification is unlikely at present. Therefore, current efforts will probably remain focused on disease mapping.

Comparison of Clinical and Reproductive Outcomes between Adenomyomectomy and Myomectomy

STUDY OBJECTIVE

Women with adenomyosis may show a lower pregnancy rate and a higher miscarriage rate than healthy women. There is also a general agreement that leiomyomas, either submucosal or intramural, negatively affect fertility, when compared with women without myomas. Some of these women may benefit from adenomyomectomy, however this cytoreductive procedure is considered invasive and technically challenging especially in severe diffuse cases. The study aimed to compare the clinical and reproductive outcomes of patients who underwent adenomyomectomy with those of patients who underwent intramural myomectomy.

DESIGN

A retrospective study.

SETTING

Department of Obstetrics & Gynecology, Center of Gynecological Endoscopy and Minimally Invasive surgery, First Faculty of Medicine, General University Hospital in Prague.

PATIENTS

A total of 55 women who underwent surgical resection of uterine adenomyosis and 55 patients who underwent myomectomy for intramural uterine myomas were included in this study. All study participants wished to retain and possibly improve their reproductive potential.

INTERVENTIONS

Between 2004 and 2019, 110 women underwent laparoscopic or open uterus-sparing surgery for clinically significant uterine adenomyosis (group A) or myomas (group B), respectively.

MEASUREMENTS AND MAIN RESULTS

Two groups of women who underwent different fertility-saving procedures were compared. Although all women entering the study had declared their wish to conceive, only 28 patients in group A (group A1) and 24 women in group B (group B1) finally aimed toward pregnancy. The mean age and follow-up period was 35.0 years and 76.81 months, respectively, in group A and 34.8 years and 72.5 months, respectively, in group B. The pregnancy and delivery rates were 75.0% and 46.4%, respectively, in group A1 vs 96.0% and 70.8%, respectively, in group B1, with no significant differences between the 2 groups. The open surgical approach was significantly more frequently employed in group A (47.3% vs 16.4%; p <.01).

CONCLUSION

In this study, women who underwent surgery involving the uterine muscularity, including myomectomy or adenomyomectomy, had comparable reproductive outcomes, with no significant differences.

[Adenomyosis pathophysiology: An unresolved enigma]

Adenomyosis is a chronic benign uterine disease characterized by the presence of endometrial glands and stroma within the myometrium. It is a heterogeneous disease, presenting various clinical forms, depending on the location of the ectopic lesions within the myometrium. Adenomyosis can be responsible for several symptoms such as dysmenorrhea, abnormal uterine bleeding and/or infertility. Its pathophysiology is a real conundrum and several theories have been proposed: development of adenomyosis lesion could initiate de novo from Mullerian rests or from stem cells. Moreover, multiple factors could be involved in initiating lesions, including specific hormonal, immune and/or genetic changes. The objective of this review is to provide an update on adenomyosis pathophysiology, in particular on the various theories proposed concerning the invasion of the myometrium by endometrial cells and the inducing mechanisms, and to study the link between the physiopathology, the symptoms and the medical treatments.

Adenomyosis: An update regarding its diagnosis and clinical features

Adenomyosis is a common gynecologic disease characterized by invasion of endometrial glands and stroma within the myometrium. Clinically, it can result in abnormal uterine bleeding, pelvic pain, and infertility. Adenomyosis has historically been diagnosed by histology of hysterectomy specimens. As a result of the development of imaging techniques, the diagnosis is nowadays possible by means of transvaginal pelvic ultrasound or pelvic magnetic resonance imaging. The use of pelvic imaging has demonstrated the existence of different forms of adenomyosis, notably allowing distinction between lesions of the external myometrium and those of the internal myometrium. The epidemiological and clinical characteristics may depend on the anatomical location of the adenomyosis lesions. In order to provide the best management for women with adenomyosis, the objective of this review is to provide an update regarding the diagnosis of adenomyosis and its clinical features according to the different adenomyosis phenotypes.

The Role of Abnormal Uterine Junction Zone in the Occurrence and Development of Adenomyosis

Adenomyosis is a benign disease with a malignant behavior, bothering a lot of women at reproductive age who suffer from increased menstruation, prolonged menstruation, progressive dysmenorrhea, and infertility. At present, there is no effective treatment for adenomyosis. It seriously affects the life quality of these patients. However, the pathogenesis of adenomyosis is not yet clear. Recently, uterus junctional zone, defined as the inner 1/3 of myometrium between endometrium and myometrium, has gained broad attention. As is reported, the structure and function disorder of uterus junctional zone may play an important part in the occurrence and development of adenomyosis. In this issue, the present study generally reviews the role of uterine junction zone and the related mechanisms involved in adenomyosis, such as the local micro-damage, the formation of inflammatory and hypoxic microenvironment, changes of cytokines, and abnormalities of miRNA as well as signal pathways. It will provide new insights and potential therapeutic target strategies for clinical strategies in the management of adenomyosis.

Clinicopathological features of different subtypes in adenomyosis: Focus on early lesions

BACKGROUND

The aim of this study is to investigate the clinicopathological features of intrinsic and extrinsic subtypes in adenomyosis. In particular, we focused on the early lesions of adenomyosis.

METHODS

This is a single-center, prospective study of women who elected surgery for adenomyosis at the Department of Gynecology, Nara Medical University Hospital, Kashihara, Japan, from April 2008 to March 2018. Adenomyosis was histologically classified as intrinsic, extrinsic, and others, depending on the type of intramural growth. Adenomyosis that occurs at the inner and outer myometrium was defined as an intrinsic and extrinsic type, respectively.

RESULTS

One hundred eighty-nine patients with histologically confirmed adenomyosis were classified into three different types, 74 intrinsic type, 78 extrinsic type, and 37 other type. Compared to the intrinsic type, the extrinsic type was more likely to have endometriosis, including ovarian endometrioma (OMA), superficial peritoneal endometriosis (SUP), or deep infiltrating endometriosis (DIE). To further identify the clinicopathological features of early-stage adenomyosis, we focused only on patients with intrinsic and extrinsic types of adenomyosis with less than one-third of muscular layer infiltration. Patients with early-stage intrinsic adenomyosis were more likely to experience induced abortions. Patients with early-stage extrinsic adenomyosis were more likely to have endometriosis. The coexistence of endometriosis and the lack of induced abortion were independent predictors of extrinsic adenomyosis. Multivariate logistic regression analysis identified coexistence of endometriosis as independent predictors of the early stage extrinsic adenomyosis.

CONCLUSION

The study suggests that there are at least two types of adenomyosis, where the intrinsic type is closely associated with a history of induced abortion, while the extrinsic type is strongly associated with endometriosis. Adenomyosis might be a gynecological disorder with complex pathogenesis implicating both traumatic and endometriotic factors.

Activation of the cGAS-STING signaling pathway in adenomyosis patients

Objective

Adenomyosis is characterized by the presence of endometrium or endometrium‐like glands and stroma within the myometrium. In this study, we aimed to investigate whether the cGAS–STING pathway was activated and correlated with clinical outcomes in adenomyosis patients.

Materials and Methods

Twenty patients diagnosed with adenomyosis and 10 patients diagnosed with cervical intraepithelial neoplasia grade 3 (CIN‐3) but no adenomyosis were enrolled in this study. Specimens were collected during surgery from August 2017 to December 2017 at Third Xiangya Hospital. The messenger RNA (mRNA) and protein levels of key cGAS–STING pathway factors in uterine tissue were detected by real‐time reverse‐transcription polymerase chain reaction and immunohistochemistry, respectively. The correlations of gene expression and clinical outcomes, including dysmenorrhea and uterine volume, were analyzed.

Results

The cGAS, STING, TANK‐binding kinase 1 (TBK‐1), interferon‐α (IFN‐α), IFN‐β, and tumor necrosis factor‐α (TNF‐α) mRNA and protein levels in the ectopic endometrial tissue from adenomyosis patients were significantly higher compared with that from the controls in endometrium (p < .05). cGAS and STING gene expression were correlated with TBK‐1, IFN‐β, and TNF‐α expression (p < .05). Importantly, TBK‐1 and TNF‐α expression were correlated with the clinical outcome of dysmenorrhea (p < .05).

Conclusion

Our study reveals that the cGAS–STING pathway is activated in adenomyosis patients and its activation is subsequently correlated with clinical outcomes, which suggests that the cGAS–STING pathway may contribute to adenomyosis pathogenesis.

Relationship between magnetic resonance imaging-based classification of adenomyosis and disease severity

AIMS

The purpose of this study is to first investigate the correlation between image features and histological findings and the clinical severity of adenomyosis; second, search for imaging features to assess the type and locoregional extension of the disease; and finally, discuss the notation of image-based classification.

METHODS

This paper combines a review of the literature on adenomyosis with a series of cases who underwent surgery at Nara Medical University Hospital.

RESULTS

Currently, there has been a lack of clear, clinically relevant, and internationally acceptable definition and histological classification due to its diverse phenotype. A number of researchers have attempted to standardize the magnetic resonance imaging (MRI) features of adenomyosis. Some researchers have begun studies that relate the subtype classification using MRI to disease severity. There is evidence suggesting that diffuse adenomyosis and intrinsic adenomyosis are correlated with menstrual bleeding, while extrinsic adenomyosis and coexistence of deep infiltrating endometriosis (DIE) are related to pelvic pain. MRI-based classifications that are simple for use in the clinical setting are beginning to be proposed. However, the reliability and validity of these classifications have not yet been verified. A simplified notation is required to discuss the association between the classification and severity of adenomyosis. We introduce case reports using the notation of four items necessary for classification of adenomyosis.

CONCLUSION

There is an urgent need to determine the definitions of terms used in subtype classification and to create and validate a globally unified notation that can predict the severity of adenomyosis symptoms.

The Multifaceted Role of Autophagy in Endometrium Homeostasis and Disease

Autophagy is a conserved fundamental cellular process with a primary function of catabolizing harmful or surplus cellular contents such as protein aggregates, dysfunctional/long-lived organelles, intracellular pathogens, and storage nutrients. An increasing body of evidence reveals that basal autophagy is essential for maintaining endometrial homeostasis and mediating endometrial-specific functions, including menstrual cycle, embryo implantation, and decidualization. However, perturbed levels of autophagy can lead to severe endometrial pathologies, including endometriosis, endometrial hyperplasia, endometrial cancer, adenomyosis, and leiomyoma. This review highlights the most recent findings on the activity, regulation, and function of autophagy in endometrium physiology and pathology. Understanding the mechanistic roles of autophagy in endometrium homeostasis and disease is key to developing novel therapeutic strategies for endometrium-related infertility and malignancies.

Adenomyosis-derived extracellular vesicles endow endometrial epithelial cells with an invasive phenotype through epithelial-mesenchymal transition

Extracellular vesicles from highly metastatic tumor cells have been shown to mediate epithelial-mesenchymal transition (EMT)-related events in recipient cells. In endometrial epithelial cells, EMT processes are known to be involved in the development of adenomyosis. We aimed to investigate whether adenomyosis-derived extracellular vesicles (AMEVs) are able to induce an EMT process in endometrial epithelial cells. In this study, AMEVs were isolated from patients with adenomyosis and characterized by transmission electron microscopy, Western blot, and nanoparticle tracking. Primary endometrial epithelial cells (EECs) were derived from normal endometrium tissues from patients with leiomyoma and co-cultured with AMEVs in vitro. AMEV uptake was examined by fluorescence confocal microscopy. The invasion of EECs was confirmed by Transwell assay. Immunohistochemistry, Western blot, and qRT-PCR were performed on EECs to illustrate the expression levels of cytokeratin 19, E-cadherin, vimentin, and zinc finger E-box-binding homeobox 1 (ZEB1). The results indicated that the cellular fluorescence intensity gradually increased after 48 h of co-culture, but decreased after 72 h. After co-culturing with AMEVs for 72 h, EECs expressed significantly lower levels of cytokeratin 19 and E-cadherin, and significantly higher levels of vimentin and ZEB1. Together these results demonstrated that AMEVs induce an EMT process and enhance the invasion of EECs. These changes may contribute to the pathogenesis and progression of adenomyosis.

Physiomimetic Models of Adenomyosis

Adenomyosis remains an enigmatic disease in the clinical and research communities. The high prevalence, diversity of morphological and symptomatic presentations, array of potential etiological explanations, and variable response to existing interventions suggest that different subgroups of patients with distinguishable mechanistic drivers of disease may exist. These factors, combined with the weak links to genetic predisposition, make the entire spectrum of the human condition challenging to model in animals. Here, after an overview of current approaches, a vision for applying physiomimetic modeling to adenomyosis is presented. Physiomimetics combines a system's biology analysis of patient populations to generate hypotheses about mechanistic bases for stratification with in vitro patient avatars to test these hypotheses. A substantial foundation for three-dimensional (3D) tissue engineering of adenomyosis lesions exists in several disparate areas: epithelial organoid technology; synthetic biomaterials matrices for epithelial–stromal coculture; smooth muscle 3D tissue engineering; and microvascular tissue engineering. These approaches can potentially be combined with microfluidic platform technologies to model the lesion microenvironment and can potentially be coupled to other microorgan systems to examine systemic effects. In vitro patient-derived models are constructed to answer specific questions leading to target identification and validation in a manner that informs preclinical research and ultimately clinical trial design.

Immunological changes associated with adenomyosis: a systematic review

BACKGROUND

Adenomyosis is a benign gynecological disorder associated with subfertility, pelvic pain and abnormal uterine bleeding that have significant consequences for the health and quality of life of women. Histologically, it is defined as the presence of ectopic endometrial islets within the myometrium. Its pathogenesis has not yet been elucidated and several pieces of the puzzle are still missing. One process involved in the development of adenomyosis is the increased capacity of some endometrial cells to infiltrate the myometrium. Moreover, the local and systemic immune systems are associated with the onset of the disease and with maintaining it. Numerous observations have highlighted the activation of immune cells and the release of immune soluble factors in adenomyosis. The contribution of immunity occurs in conjunction with hormonal aberrations and activation of the epithelial to mesenchymal transition (EMT) pathway, which promotes migration of endometrial cells. Here, we review current knowledge on the immunological changes in adenomyosis, with the aim of further elucidation of the pathogenesis of this disease.

OBJECTIVE AND RATIONALE

The objective was to systematically review the literature regarding the role of the immune system in development of adenomyosis in the inner and the outer myometrium, in humans.

SEARCH METHODS

A systematic review of published human studies was performed in MEDLINE, EMBASE and Cochrane Library databases from 1970 to February 2019 using the combination of Medical Subject Headings (MeSH): Adenomyosis AND ('Immune System' OR 'Gonadal Steroid Hormones'), and free-text terms for the following search terms (and their variants): Adenomyosis AND (immunity OR immune OR macrophage OR 'natural killer cell' OR lymphocyte* OR leucocyte* OR HLA OR inflammation OR 'sex steroid' OR 'epithelial to mesenchymal transition' OR 'EMT'). Studies in which no comparison was made with control patients, without adenomyosis (systemic sample and/or eutopic endometrium), were excluded.

OUTCOMES

A total of 42 articles were included in our systematic review. Changes in innate and adaptive immune cell numbers were described in the eutopic and/or ectopic endometrium of women with adenomyosis compared to disease-free counterparts. They mostly described an increase in lymphocyte and macrophage cell populations in adenomyosis eutopic endometrium compared to controls. These observations underscore the immune contributions to the disease pathogenesis. Thirty-one cytokines and other markers involved in immune pathways were studied in the included articles. Pro-inflammatory cytokines (interleukin (IL) 6, IL1β, interferon (IFN) α, tumor necrosis factor α, IFNγ) as well as anti-inflammatory or regulatory mediators (IL10, transforming growth factor β…) were found to be elevated in the eutopic endometrium and/or in the ectopic endometrium of the myometrium in women with adenomyosis compared to controls. Moreover, in women affected by adenomyosis, immunity was reported to be directly or indirectly linked to sex steroid hormone aberrations (notably changes in progesterone receptor in eutopic and ectopic endometrium) in three studies and to EMT in four studies.

WIDER IMPLICATIONS

The available literature clearly depicts immunological changes that are associated with adenomyosis. Both systemic and local immune changes have been described in women affected by adenomyosis, with the coexistence of changes in inflammatory as well as anti-inflammatory signals. It is likely that these immune changes, through an EMT mechanism, stimulate the migration of endometrial cells into the myometrium that, together with an endocrine imbalance, promote this inflammatory process. In light of the considerable impact of adenomyosis on women's health, a better understanding of the role played by the immune system in adenomyosis is likely to yield new research opportunities to better understand its pathogenesis.

Focal adenomyosis is associated with primary infertility

OBJECTIVE

To study the association between adenomyosis and infertility, according to the adenomyosis phenotype as diagnosed by magnetic resonance imaging (MRI).

DESIGN

A single-center, cross-sectional study.

SETTING

University hospital-based research center.

PATIENT(S)

Patients between 18 and 42 years of age who were surgically explored for benign gynecological conditions at our institution between May 2005 and May 2018. Only women with uterine MRIs performed by a senior radiologist were retained for this study.

INTERVENTION(S)

Primary and secondary infertile women were compared with women without infertility. In addition, the women were diagnosed according to the MRI findings as having adenomyosis (focal adenomyosis of the outer myometrium [FAOM] and/or diffuse adenomyosis phenotypes) or no adenomyosis.

MAIN OUTCOME MEASURE(S)

Primary and secondary infertility-associated factors.

RESULT(S)

A total of 496 women were included in the study population. Three groups were compared: a no infertility group (n = 361), a primary infertility group (n = 84), and a secondary infertility group (n = 51). Among them, 248 women did not present adenomyosis lesions and 248 women had a radiological diagnosis of adenomyosis. The presence of FAOM was significantly associated with primary infertility. Diffuse adenomyosis was not found to be associated with infertility. The distribution of endometriosis or leiomyomas was not significantly different between the groups. After a multinomial regression model including the women's age and associated endometriosis or leiomyoma, the presence of FAOM was identified as an independent associated factor of primary infertility (adjusted odds ratio 1.9; 95% confidence interval 1.1-3.3).

CONCLUSION(S)

The presence of FAOM was associated with primary infertility. This study opens the door to future clinical and basic studies aimed at better characterization of FAOM and its infertility-related physiopathology.

The effect of adenomyosis on IVF after long or ultra-long GnRH agonist treatment

RESEARCH QUESTION

Does adenomyosis affect IVF independent of decreased ovarian reserve, and what are the characteristics and IVF outcome of the ultra-long gonadotrophin-releasing hormone (GnRH) agonist protocol in adenomyosis?

DESIGN

Observational cohort study of three groups of patients undergoing first cycle of IVF treatment with normal ovarian reserve: (A) 362 patients with adenomyosis using the ultra-long GnRH agonist protocol; (B) 127 patients with adenomyosis using the long GnRH agonist protocol; (C) 3471 patients with tubal infertility using the long GnRH agonist protocol.

RESULTS

Compared with groups B and C, the number of oocytes retrieved in group A decreased, and the gonadotrophin dosage and duration in group A were higher (P < 0.001). In long GnRH agonist treatment, clinical pregnancy rate (OR 0.492, 95% CI 0.327 to 0.742, P < 0.001), implantation rate (OR 0.527, 95% CI 0.350 to 0.794, P = 0.002) and live birth rate (OR 0.442, 95% CI 0.291 to 0.673, P < 0.001) decreased and miscarriage rate (OR 3.078, 95% CI 1.593 to 5.948, P < 0.001) increased in adenomyosis patients compared with tubal infertility. For adenomyosis patients, clinical pregnancy rate (OR 1.925, 95% CI 1.137 to 3.250, P = 0.015), implantation rate (OR 1.694, 95% CI 1.006 to 2.854, P = 0.047) and live birth rate (OR 1.704, 95% CI 1.012 to 2.859, P = 0.044) increased in the ultra-long GnRH agonist treatment compared with long GnRH agonist treatments.

CONCLUSION

Adenomyosis could negatively affect IVF outcomes independent of ovarian reserve after long GnRH agonist protocol. Patients with adenomyosis following the ultra-long GnRH agonist protocol could have a better pregnancy outcome than those following the long GnRH agonist protocol.

m6A RNA Methylation Regulators Contribute to Eutopic Endometrium and Myometrium Dysfunction in Adenomyosis

Adenomyosis is a prevalent, estrogen-dependent uterine disorder wherein endometrial cells are abnormally present in the myometrium and are surrounded by hyperplastic/hypertrophic smooth muscle. Its etiology is unclear, although endometrial cell invasion into the myometrium has been postulated. RNA methylation, particularly N6-methyladenosine (m6A), plays an important role in regulating various physiological processes and invasive disorders. The goal of this in silico and lab-based experimental study was to explore a possible role for m6A in adenomyosis. Gene expression profiles of both the endometrium and myometrium of women with adenomyosis (cases) and without disease (controls) were obtained from the publicly available Gene Expression Omnibus (GEO) database. In the endometrium, STRING database analysis revealed that METTL3 functions as a "hub" gene of m6A RNA methylation regulators, and the genes involved in m6A regulation, including METTL3, FTO, ZC3H13, and YTHDC1 expression, were significantly decreased in cases versus controls. Functional, co-expression, and correlational analyses of endometrium from cases versus controls revealed decreased total m6A levels, induced by METTL3, and the downstream elevated insulin-like growth factor-1(IGF1) and D-Dopachrome Tautomerase (DDT), with the latter two having known functions in epithelial proliferation and cell migration, which are important processes in the pathogenesis of adenomyosis in endometrium. m6A RNA methylation regulators, including RBM15/15B, ALKBH5, FTO, YTHDF1/2, KIAA1429, HNRNPC, METTL3, ZC3H13, and YTHDC2, were also differentially expressed in the myometrium from cases versus controls. We validated decreased total m6A levels and differential expression of m6A RNA methylation regulators in the myometrium of patients with adenomyosis using qRT-PCR, immunohistochemistry and tissues available from our biorepository. Possible target genes, including cadherin 3(CDH3), sodium channelβ-subunit 4 (SCN4B), and placenta-specific protein 8 (PLAC8), which are involved in cell adhesion, muscle contraction and immune response in the myometrium of adenomyosis patients were also validated. Thus, through extensive public database mining and validation of select genes, this study, for the first time, implicates m6A and its methylation regulators in the pathogenesis of adenomyosis. Follow on functional studies are anticipated to elucidate mechanisms involving m6A and its regulators and down-stream effectors in the pathogenesis of this enigmatic reproductive disorder and potentially identify druggable targets to control its associated symptoms.

PIWIL2 is overexpressed in adenomyotic lesions of women with diffuse adenomyosis

PURPOSE

Adenomyosis has been studied throughout the years, however, its aetiology and physiopathology are still unknown. The aim of this study was to identify the presence of PIWI proteins in women with adenomyosis.

METHODS

We included 72 participants to be part of this study and were divided into two groups based on their anatomopathological diagnosis, control (n = 36) or adenomyosis (n = 36). All samples were tested for PIWIL1, PIWIL2 and PIWIL4 proteins by immunohistochemistry. The evaluation of protein expression was performed by the digital histological score (DHSCORE) and by the pathologist's analysis.

RESULTS

The participants had a mean age of 44.28 ± 5.76 years and 45.81 ± 4.86 years in the control and adenomyosis groups, respectively (p ≥ 0.05). Other clinical characteristics of the participants showed no statistical difference as well. PIWIL2 is highly expressed in the adenomyosis in comparison to the control group (p = 0.0001). The PIWIL1 is downregulated in the adenomyosis (p = 0.003) and PIWIL4 showed no difference in its expression (p = 0.05).

CONCLUSION

PIWIL2 might be involved in cellular survival and PIWIL1 may be downregulated due to the loss of tissue's function and response to the hostile environment of the myometrium. This is the first time that PIWI proteins are studied in the adenomyosis.

Role of angiogenesis in adenomyosis-associated abnormal uterine bleeding and subfertility: a systematic review

BACKGROUND

Adenomyosis commonly occurs with abnormal uterine bleeding (AUB) and is associated with subfertility and a higher miscarriage rate. Recent evidence showed abnormal vascularization in the endometrium in patients with adenomyosis, suggesting a role of angiogenesis in the pathophysiology of AUB and subfertility in adenomyosis and providing a possible treatment target.

OBJECTIVE AND RATIONALE

We hypothesized that the level of abnormal vascularization and expression of angiogenic markers is increased in the ectopic and eutopic endometrium of adenomyosis patients in comparison with the endometrium of control patients. This was investigated through a search of the literature.

SEARCH METHODS

A systematic search was performed in PubMed and Embase until February 2019. Combinations of terms for angiogenesis and adenomyosis were applied as well as AUB, subfertility or anti-angiogenic therapy. The main search was limited to clinical studies carried out on premenopausal women. Original research articles focusing on markers of angiogenesis in the endometrium of patients with adenomyosis were included. Studies in which no comparison was made to control patients or which were not published in a peer-reviewed journal were excluded. A second search was performed to explore the therapeutic potential of targeting angiogenesis in adenomyosis. This search also included preclinical studies.

OUTCOMES

A total of 20 articles out of 1669 hits met our selection criteria. The mean vascular density (MVD) was studied by quantification of CD31, CD34, von Willebrand Factor (vWF) or factor-VIII-antibody-stained microvessels in seven studies. All these studies reported a significantly increased MVD in ectopic endometrium, and out of the six articles that took it into account, four studies reported a significantly increased MVD in eutopic endometrium compared with control endometrium. Five articles showed a significantly higher vascular endothelial growth factor expression in ectopic endometrium and three articles in eutopic endometrium compared with control endometrium. The vascular and pro-angiogenic markers α-smooth muscle actin, endoglin, S100A13, vimentin, matrix metalloproteinases (MMPs), nuclear factor (NF)-kB, tissue factor (TF), DJ-1, phosphorylated mammalian target of rapamycin, activin A, folli- and myostatin, CD41, SLIT, roundabout 1 (ROBO1), cyclooxygenase-2, lysophosphatidic acid (LPA) 1,4-5, phospho signal transducer and activator of transcription 3 (pSTAT3), interleukin (IL)-6, IL-22 and transforming growth factor-β1 were increased in ectopic endometrium, and the markers S100A13, MMP-2 and -9, TF, follistatin, myostatin, ROBO1, LPA1 and 4-5, pSTAT3, IL-6 and IL-22 were increased in eutopic endometrium, compared with control endometrium. The anti-angiogenic markers E-cadherin, eukaryotic translation initiation factor 3 subunit and gene associated with retinoic-interferon-induced mortality 19 were decreased in ectopic endometrium and IL-10 in eutopic endometrium, compared with control endometrium. The staining level of vWF and two pro-angiogenic markers (NF-κB nuclear p65 and TF) correlated with AUB in patients with adenomyosis. We found no studies that investigated the possible relationship between markers of angiogenesis and subfertility in adenomyosis patients. Nine articles reported on direct or indirect targeting of angiogenesis in adenomyosis-either by testing hormonal therapy or herbal compounds in clinical studies or by testing angiogenesis inhibitors in preclinical studies. However, there are no clinical studies on the effectiveness of such therapy for adenomyosis-related AUB or subfertility.

WIDER IMPLICATIONS

The results are in agreement with our hypothesis that increased angiogenesis is present in the endometrium of patients with adenomyosis compared with the endometrium of control patients. It is likely that increased angiogenesis leads to fragile and more permeable vessels resulting in adenomyosis-related AUB and possibly subfertility. While this association has not sufficiently been studied yet, our results encourage future studies to investigate the exact role of angiogenesis in the etiology of adenomyosis and related AUB or subfertility in women with adenomyosis in order to design curative or preventive therapeutic strategies.

Pathophysiologic mechanisms by which adenomyosis predisposes to postpartum haemorrhage and other obstetric complications

Adenomyosis is characterized by the presence of ectopic endometrium within the myometrium. This features lead to structural changes in the surrounding myometrium and endometrium resulting also in functional changes. Alterations in the myometrium are suspected to lead to defective remodeling of spiral arteries during the early stages of decidualization resulting in altered vascular resistance and defective placentation. These alterations could play a common part in the association between adenomyosis and major obstetric complications. Latest epidemiological studies show that adenomyosis is associated with preterm birth, preeclampsia, IUGR and increased caesarean section rates, but very little is known of any underlying mechanism linking postpartum hemorrhage and adenomyosis. It is our opinion that adenomyosis may increase the risk of postpartum hemorrhage through several mechanisms that will be further clarified. Women with adenomyosis may require specific management during pregnancy and may benefit from wider understanding of the pathological mechanisms associated with this disease process.