Phenotypic characterization of adenomyosis occurring at the inner and outer myometrium

Adenomyosis and fertility-sparing surgery: A literature appraisal

Adenomyosis is an intricate pathological condition that negatively impacts the uterus. It is closely related to the more well-known endometriosis, with which it shares parallels in terms of diagnosis, therapy, and both microscopic and macroscopic features. The purpose of this narrative review is to give a clear univocal definition and outlook on the different, patient-adapted, surgical treatments. MEDLINE and PubMed searches on these topics were conducted from 1990 to 2022 using a mix of selected keywords. Papers and articles were identified and included in this narrative review after authors' revision and evaluation. From the literature analysis, authors reported the following surgical techniques: laparoscopic double/triple-flap method, laparotomic wedge resection of the uterine wall, laparotomic transverse H-incision of the uterine wall, laparotomic wedge-shaped excision, and laparotomic complete debulking excision by asymmetric dissection technique. Each of these techniques has strengths and weaknesses, but the literature data on the pregnancy rate are somewhat limited. The only certain information is the risk of uterine rupture up to 6.0% after surgical treatment for uterine adenomyosis. Over the years, the surgical approach continued to reach a positive result by minimally invasive treatment, with less hospitalization, less postoperative pain, and less blood loss. Over the years, the gynecological surgeon has gained the skills, training and increasingly sophisticated surgical techniques to target effective therapy. That's why a hysterectomy is no longer the only surgical resource to treat adenomyosis, but in patients who wish to preserve the fertility, there is a wide variety of surgical alternatives.

Comparative analysis of endometrial, vaginal, and gut microbiota in patients with and without adenomyosis

INTRODUCTION

Alterations in microbiota composition have been implicated in a variety of human diseases. Patients with adenomyosis present immune dysregulation leading to a persistent chronic inflammatory response. In this context, the hypothesis that alterations in the microbiota may be involved in the pathogenesis of adenomyosis, by affecting the epigenetic, immunologic, and biochemical functions of the host, has recently been postulated. The aim of the present study was to compare the microbiota composition in the vagina, endometrium, and gut of individuals with and without adenomyosis.

MATERIAL AND METHODS

Cross-sectional study including 38 adenomyosis patients and 46 controls, performed between September 2021 and October 2022 in a university hospital-based research center. The diagnosis of adenomyosis was based on sonographic criteria. Fecal, vaginal, and endometrial samples were collected. Study of the microbiota using 16S rRNA gene sequencing.

RESULTS

Patients with adenomyosis exhibited a significant reduction in the gut microbial alpha diversity compared with healthy controls (Chao1 p = 0.012, Fisher p = 0.005, Observed species p = 0.005). Beta-diversity analysis showed significant differences in the compositions of both gut and vaginal microbiota between adenomyosis patients and the control group (Adonis p-value = 0.001; R2 = 0.03 and Adonis p-value = 0.034; R2 = 0.04 respectively). Specific bacterial taxa were found to be either overrepresented (Rhodospirillales, Ruminococcus gauvreauii group, Ruminococcaceae, and Actinomyces) or underrepresented in the gut and endometrial microbiota of adenomyosis patients compared with controls. Distinct microbiota profiles were identified among patients with internal and external adenomyosis phenotypes.

CONCLUSIONS

The study revealed reduced gut microbiota diversity in adenomyosis patients, accompanied by distinct compositions in gut and vaginal microbiota compared with controls. Overrepresented or underrepresented bacterial taxa were noted in the gut and endometrial microbiota of adenomyosis patients, with variations in microbiota profiles among those with internal and external adenomyosis phenotypes. These findings suggest a potential association between microbiota and adenomyosis, indicating the need for further research to comprehensively understand the implications of these differences.

Magnetic Resonance Imaging-Based Classification Systems for Informing Better Outcomes of Adenomyosis After Ultrasound-Guided High-Intensity Focused Ultrasound Ablating Surgery

BACKGROUND

A referenced MRI-based classification associated with focused ultrasound ablation surgery (FUAS) outcomes is lacking in adenomyosis.

PURPOSE

To identify an MRI-based classification system for informing the FUAS outcomes.

STUDY TYPE

Retrospective.

POPULATION

Patients with FUAS for adenomyosis, were divided into a training set (N = 643; 355 with post-FUAS gonadotropin-releasing hormone/levonorgestrel, 288 without post-FUAS therapy) and an external validation set (N = 135; all without post-FUAS therapy).

FIELD STRENGTH/SEQUENCE

1.5 T, turbo spin-echo T2-weighted imaging and single-shot echo-planar diffusion-weighted imaging sequences.

ASSESSMENT

Five MRI-based adenomyosis classifications: classification 1 (C1) (diffuse, focal, and mild), C2 (intrinsic, extrinsic, intramural, and indeterminate), C3 (internal, adenomyomas, and external), C4 (six subtypes on areas [internal or external] and volumes [<1/3 or ≥2/3]), and C5 (internal [asymmetric or symmetric], external, intramural, full thickness [asymmetric or symmetric]) for FUAS outcomes (symptom relief and recurrence).

STATISTICAL TESTS

The optimal classification was significantly associated with the most subtypes of FUAS outcomes. Relating to the timing of recurrence was measured using Cox regression analysis and median recurrence time was estimated by a Kaplan-Meier curve. A P value <0.05 was considered statistically significant.

RESULTS

Dysmenorrhea relief and recurrence were only associated with C2 in training patients undergoing FUAS alone. Compared with other subtypes, the extrinsic subtype of C2 was significantly associated with dysmenorrhea recurrence in the FUAS group. Besides, the median dysmenorrhea recurrence time of extrinsic subtype was significantly shorter than that of other subtypes (42.0 months vs. 50.3 months). In the validation cohort, C2 was confirmed as the optimal system and its extrinsic subtype was confirmed to have a significantly shorter dysmenorrhea recurrence time than other subtypes.

DATA CONCLUSION

Classification 2 can inform dysmenorrhea relief and recurrence in patients with adenomyosis undergoing FAUS only. Itsextrinsic subtype was associated with an earlier onset of dysmenorrhea recurrence after treatment.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: Stage 5.

Type and Location of Adenomyosis in Women with Recurrent Pregnancy Loss: A Transvaginal Ultrasonographic Assessment

The current knowledge on adenomyosis as a risk factor for RPL is very scant. Overall 120 women were included in this retrospective observational study. They were divided in three groups each of which consisted of 40 subjects: Group 1: women with RPL who were diagnosed to have adenomyosis on transvaginal ultrasound (TVS); Group 2: patients with RPL without ultrasonographic findings of adenomyosis; Group 3: patients with ultrasound diagnosis of adenomyosis without RPL and at least one live birth pregnancy. The copresence of endometriosis was also investigated. Among women with RPL, patients with adenomyosis (Group 1) had higher number of pregnancy losses (p = 0.03) and lower age at first pregnancy loss (p = 0.03) than women without adenomyosis (Group 2). Moreover, they had more frequently primary RPL (p = 0.008). Adenomyosis of the inner myometrium was found more frequently (p = 0.04) in patients of Group 1 than in patients of Group 3 in which adenomyosis was mainly in the outer myometrium (p= 0.02). No differences were found in the severity of adenomyosis between these two groups of women. TVS findings for endometriosis were observed more frequently in women with adenomyosis without RPL (Group 3) than in the other two groups of patients. Adenomyosis can be a factor involved in RPL. Differences in adenomyosis localization are associated with different risks for RPL. Patients with RPL should be investigated for the presence of adenomyosis and also for the type and localization of the disease in the different myometrial layers.

Transforming growth factor beta-1 (TGF-β1) expression in patients with adenomyosis

Objective

To compare Transforming growth factor beta-1 (TGF-β1) expression in patients with and without adenomyosis.

Methods

A prospective design was performed including 49 patients submitted to hysterectomy. Immunohistochemistry was performed on anatomopathological samples staged in paraffin blocks from patients with and without adenomyosis. The sample contained 28 adenomyosis cases and 21 controls. Student's t-test and multivariate logistic regression tests were used for statistical analysis. Associations were considered significant at p < 0.05.

Results

We found no significant association between adenomyosis and: smoking (p = 0.75), miscarriage (p = 0.29), number of previous pregnancies (p = 0.85), curettage (p = 0.81), pelvic pain (p = 0.72) and myoma (p = 0.15). However, we did find a relationship between adenomyosis and abnormal uterine bleeding (AUB) (p = 0.02) and previous cesarean section (p = 0.02). The mean TGF-β1 intensity (mean ± SD) in the ectopic endometrium of women with adenomyosis showed no significant association (184.17 ± 9.4 vs.184.66 ± 16.08, p = 0.86) from the topic endometrium of women without adenomyosis.

Conclusion

TGF-β1 expression was not increased in the ectopic endometrium of women with adenomyosis.

Progress of the study of pericytes and their potential research value in adenomyosis

Pericytes (PCs) are versatile cells integral to the microcirculation wall, exhibiting specific stem cell traits. They are essential in modulating blood flow, ensuring vascular permeability, maintaining homeostasis, and aiding tissue repair process. Given their involvement in numerous disease-related pathological and physiological processes, the regulation of PCs has emerged as a focal point of research. Adenomyosis is characterized by the presence of active endometrial glands and stroma encased by an enlarged and proliferative myometrial layer, further accompanied by fibrosis and new blood vessel formation. This distinct pathological condition might be intricately linked with PCs. This article comprehensively reviews the markers associated with PCs, their contributions to angiogenesis, blood flow modulation, and fibrotic processes. Moreover, it provides a comprehensive overview of the current research on adenomyosis pathophysiology, emphasizing the potential correlation and future implications regarding PCs and the development of adenomyosis.

Increased chemokine ligand 26 expression and its involvement in epithelial-mesenchymal transition in the endometrium with adenomyosis

OBJECTIVE

Adenomyosis is a gynecologic disorder characterized by symptoms of dysmenorrhea, abnormal uterine bleeding, and infertility. This study aimed to analyze the expression profiles of key inflammatory cytokines in the endometrium with adenomyosis and their involvement in epithelial-mesenchymal transition (EMT).

STUDY DESIGN

Endometrial tissues collected from premenopausal women with (n = 3) or without (n = 3) adenomyosis during the secretory phase were subjected to DNA array analysis to examine inflammatory cytokines. The gene and protein expression levels were re-evaluated by reverse transcription-polymerase chain reaction (n = 19) and immunohistochemistry (n = 56). Immunohistochemical analysis using the Histo-scores of chemokine ligand 26 (CCL26) and EMT-related factors was performed with uterine tissues resected for adenomyosis (n = 37), including those from patients treated with gonadotropin-releasing hormone agonist (GnRHa). An invasion assay was also performed using endometrial epithelial cells.

RESULTS

DNA array results showed that CCL26, IL-1B, and CCL3 were upregulated. CCL26 mRNA expression was markedly higher in the endometrium with adenomyosis than in that without adenomyosis. Immunohistochemical analysis revealed that CCL26 expression was elevated in the epithelial cells of the basal layer of the endometrium with adenomyosis than in that without adenomyosis regardless of GnRHa treatment. In the basal layer of the endometrium with adenomyosis, CCL26 expression was positively correlated with neural-cadherin and ZEB1 expression; additionally, the cases with intrinsic-type adenomyosis had high expression levels of CCL26 and ZEB1. Exogenous CCL26 promoted the invasive activity of endometrial epithelial cells.

CONCLUSIONS

CCL26, an inflammatory mediator, may be involved in the pathogenesis of adenomyosis by inducing EMT in the basal layer of the endometrium.

Magnetic resonance imaging presentation of diffuse and focal adenomyosis before and after pregnancy

RESEARCH QUESTION

Is there a change in magnetic resonance imaging (MRI) criteria of diffuse and focal phenotypes of adenomyosis before and after pregnancy?

DESIGN

A retrospective, monocentric, observational study in a single academic tertiary referral centre for endometriosis diagnosis and management. Women were followed for symptomatic adenomyosis, and without a prior history of surgery who give birth after 24+0 weeks. For each patient, pelvic MRI pre- and post-pregnancy was performed by two experienced radiologists with the same image acquisition protocol. Diffuse and focal adenomyosis MRI presentation were analysed before and after pregnancy.

RESULTS

Between January 2010 and September 2020, of the 139 patients analysed, 96 (69.1%) had adenomyosis at MRI distributed as follow: 22 (15.8%) presented diffuse adenomyosis, 55 (39.6%) focal adenomyosis and 19 (13.7%) both phenotypes. The frequency of isolated diffuse adenomyosis on MRI was significantly lower before versus after pregnancy (n = 22 [15.8%] versus n = 41 [29.5%], P = 0.01). The frequency of isolated focal adenomyosis was significantly higher before pregnancy than after pregnancy (n = 55 [39.6%] versus n = 34 [24.5%], P = 0.01). The mean volume of all focal adenomyosis lesions on MRI decreased significantly after pregnancy, from 6.7 ± 2.5 mm3 to 6.4 ± 2.3 mm3, P = 0.01.

CONCLUSION

The current data indicate that, based on MRI, there is an increase in diffuse adenomyosis and a decrease in focal adenomyosis after pregnancy.

Endometrial Inflammation and Impaired Spontaneous Decidualization: Insights into the Pathogenesis of Adenomyosis

Adenomyosis is an estrogen-dependent gynecologic disease characterized by the myometrial invasion of the endometrial tissue. This review summarized the current understanding and recent findings on the pathophysiology of adenomyosis, focusing on repeated menstruation, persistent inflammation, and impaired spontaneous decidualization. A literature search was performed in the PubMed and Google Scholar databases from inception to 30 April 2022. Thirty-one full-text articles met the eligibility criteria. Repeated episodes of physiological events (i.e., endometrial shedding, damage, proliferation, differentiation, repair, and regeneration) during the menstrual cycle are associated with inflammation, angiogenesis, and immune processes. The decidualization process in humans is driven by the rise in progesterone levels, independently of pregnancy (i.e., spontaneous decidualization). Adenomyotic cells produce angiogenic and fibrogenic factors with the downregulation of decidualization-associated molecules. This decidualization dysfunction and persistent inflammation are closely related to the pathogenesis of adenomyosis. Recently, it has been found that the reproductive tract microbiota composition and function in women with adenomyosis differ from those without. An increase in opportunistic pathogens and a decrease in beneficial commensals may promote impaired defense mechanisms against inflammation and predispose women to uncontrolled endometrial inflammation. However, currently, there is no direct evidence that adenomyosis is linked to pre-existing inflammation and impaired spontaneous decidualization. Overall, persistent inflammation, impaired spontaneous decidualization, and microbiota dysbiosis (i.e., an imbalance in the composition and function of endometrial microbiota) may be involved in the pathophysiology of adenomyosis.

Heterogeneity of clinical symptoms and therapeutic strategies for different subtypes of adenomyosis: An initial single-center study in China

OBJECTIVE

To investigate the relationship between the magnetic resonance imaging (MRI) classification of different clinical symptoms and corresponding therapeutic efficacy in adenomyosis patients.

METHODS

From January 2015 to October 2020, a total of 468 patients diagnosed with adenomyosis through MRI examination at Peking University Third Hospital were included in this retrospective cohort study. Totals of 184 (39.3%), 208 (44.4%), 17 (3.6%), and 59 (12.6%) patients were categorized into Subtypes I (intrinsic), II (extrinsic), III (intramural), and IV (penetrating), respectively. Clinical information such as age, dysmenorrhea, menorrhagia, infertility, assisted reproduction, and drug treatment and its efficacy were analyzed. By comparing the clinical information of different adenomyosis subtypes, we intend to provide better fertility guidance and find better treatment strategies for these patients.

RESULTS

The proportion of dysmenorrhea increased in intrinsic, extrinsic, intramural, and penetrating subtypes (74.5% vs 82.7% vs 94.1% vs 94.9%, respectively, P = 0.002). The proportion of menorrhagia in the intrinsic subtype (53.3%) was significantly higher than that in the extrinsic (28.4%) and intramural (29.4%) subtypes (P < 0.001). The effective rate of progesterone in the intrinsic subtype was significantly lower than that in the extrinsic subtype (52.0% vs 86.5%, P < 0.001). The infertility rates of adenomyosis patients with different subtypes were relatively high (17.6%-41.3%), and that of the extrinsic subtype was the highest among all the subtype groups (41.3%, P < 0.001).

CONCLUSIONS

Significant differences in age, dysmenorrhea, menorrhagia, and infertility were found among patients with different subtypes of adenomyosis. A novel classification of adenomyosis was proposed to provide a theoretical basis for the treatment of adenomyosis patients with infertility.

In Search of an Imaging Classification of Adenomyosis: A Role for Elastography?

Adenomyosis is a complex and poorly understood gynecological disease. It used to be diagnosed exclusively by histology after hysterectomy; today its diagnosis is carried out increasingly by imaging techniques, including transvaginal ultrasound (TVUS) and magnetic resonance imaging (MRI). However, the lack of a consensus on a classification system hampers relating imaging findings with disease severity or with the histopathological features of the disease, making it difficult to properly inform patients and clinicians regarding prognosis and appropriate management, as well as to compare different studies. Capitalizing on our grasp of key features of lesional natural history, here we propose adding elastographic findings into a new imaging classification of adenomyosis, incorporating affected area, pattern, the stiffest value of adenomyotic lesions as well as the neighboring tissues, and other pathologies. We argue that the tissue stiffness as measured by elastography, which has a wider dynamic detection range, quantitates a fundamental biologic property that directs cell function and fate in tissues, and correlates with the extent of lesional fibrosis, a proxy for lesional "age" known to correlate with vascularity and hormonal receptor activity. With this new addition, we believe that the resulting classification system could better inform patients and clinicians regarding prognosis and the most appropriate treatment modality, thus filling a void.

Uterine junctional zone and adenomyosis: comparison of MRI, transvaginal ultrasound and histology

The uterine junctional zone is the subendometrial area in the myometrium that contributes to peristalsis and aids in spermatozoa and blastocyst transport. Alterations in the appearance of the junctional zone on transvaginal sonography (TVS) or magnetic resonance imaging (MRI) are associated with adenomyosis. The lack of standardization of description of its appearance and ill-defined boundaries on both histology and imaging hamper understanding of the junctional zone and limit its role in the diagnosis of adenomyosis. The objectives of this review were to investigate the accordance in definition of the junctional zone across different diagnostic approaches and to examine how imaging findings can be linked to histological findings in the context of diagnosis of adenomyosis. A comprehensive literature review was conducted of articles describing the appearance on imaging and the histological structure of the uterine junctional zone. Our review suggests that the junctional zone is distinguished from the middle and outer myometrium by gradual changes in smooth-muscle cell density, extracellular space, connective tissue, water content and vascular properties. However, while the signal intensity from the junctional zone to the middle myometrium changes abruptly on MRI, the histopathological changes are gradual and its border may be difficult or impossible to distinguish on two-dimensional TVS. Moreover, the thickness of the junctional zone measured on MRI is larger than that measured on TVS. Thus, these two imaging modalities reflect this zone differently. Although a thickened junctional zone is often used to diagnose adenomyosis on MRI, the presence of adenomyosis can be described more accurately as interruptions of the junctional zone by endometrial tissue, which leads to direct signs on imaging such as subendometrial lines and buds on two- and three-dimensional TVS or bright foci on MRI. The histopathological criteria for diagnosis are based on enlargement of the uterus with severe adenomyosis, and might not reflect its early stages. Clinicians should be aware that findings on MRI cannot be extrapolated readily to ultrasound. An understanding of this is necessary when investigating the uterine junctional zone as a functional unit and the association between visualization of direct features of adenomyosis in the junctional zone and clinical symptoms. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Uterine disorders and iron deficiency anemia

Abnormal uterine bleeding (AUB) is a clinical entity which can lead to iron deficiency anemia. Classification according to the acronym PALM-COEIN (polyp, adenomyosis, leiomyoma, malignancy, and hyperplasia; coagulopathy, ovulatory dysfunction, endometrial, iatrogenic, and not otherwise classified) provides a structured approach to establish the cause of AUB. The goal of this review is to discuss the different mechanisms and the relationship between uterine disorders and AUB. Heavy menstrual bleeding, a subgroup of AUB, is more closely related to the presence of uterine fibroids. The relationship between heavy menstrual bleeding and uterine fibroids remains poorly characterized, particularly the understanding of endometrial function in women with structural myometrial features such as leiomyomas. A number of theories have been proposed in the literature and are discussed in this review. Uterine adenomyosis is also a frequent cause of AUB, and its pathogenesis is still far from being fully elucidated. The mechanisms contributing to its development are multifactorial. Many theories lean toward invasion of the myometrium by endometrial cells. Both clinical and basic studies favor the theory of direct invasion, although de novo development of adenomyosis from Müllerian rests or stem cells has not been ruled out. Development of adenomyotic lesions involves repeated tissue injury and repair. In addition, this review describes the other causes of AUB such as endometrial polyps, cesarean scar defects, and uterine vascular abnormalities. Endometrial polyps are often asymptomatic, but approximately 68% of women have concomitant AUB. Histologic alterations in the lower uterine segment in patients who had undergone cesarean sections were identified and may explain the cause of AUB.

The Potential Relationship Between Environmental Endocrine Disruptor Exposure and the Development of Endometriosis and Adenomyosis

Women with endometriosis, the growth of endometrial glands and stroma outside the uterus, commonly also exhibit adenomyosis, the growth of endometrial tissues within the uterine muscle. Each disease is associated with functional alterations in the eutopic endometrium frequently leading to pain, reduced fertility, and an increased risk of adverse pregnancy outcomes. Although the precise etiology of either disease is poorly understood, evidence suggests that the presence of endometriosis may be a contributing factor to the subsequent development of adenomyosis as a consequence of an altered, systemic inflammatory response. Herein, we will discuss the potential role of exposure to environmental toxicants with endocrine disrupting capabilities in the pathogenesis of both endometriosis and adenomyosis. Numerous epidemiology and experimental studies support a role for environmental endocrine disrupting chemicals (EDCs) in the development of endometriosis; however, only a few studies have examined the potential relationship between toxicant exposures and the risk of adenomyosis. Nevertheless, since women with endometriosis are also frequently found to have adenomyosis, discussion of EDC exposure and development of each of these diseases is relevant. We will discuss the potential mechanisms by which EDCs may act to promote the co-development of endometriosis and adenomyosis. Understanding the disease-promoting mechanisms of environmental toxicants related to endometriosis and adenomyosis is paramount to designing more effective treatment(s) and preventative strategies.

Novel microarchitecture of human endometrial glands: implications in endometrial regeneration and pathologies

BACKGROUND

Human endometrium remains a poorly understood tissue of the female reproductive tract. The superficial endometrial functionalis, the site of embryo implantation, is repeatedly shed with menstruation, and the stem cell-rich deeper basalis is postulated to be responsible for the regeneration of the functionalis. Two recent manuscripts have demonstrated the 3D architecture of endometrial glands. These manuscripts have challenged and replaced the prevailing concept that these glands end in blind pouches in the basalis layer that contain stem cells in crypts, as in the intestinal mucosa, providing a new paradigm for endometrial glandular anatomy. This necessitates re-evaluation of the available evidence on human endometrial regeneration in both health and disease in the context of this previously unknown endometrial glandular arrangement.

OBJECTIVE AND RATIONALE

The aim of this review is to determine if the recently discovered glandular arrangement provides plausible explanations for previously unanswered questions related to human endometrial biology. Specifically, it will focus on re-appraising the theories related to endometrial regeneration, location of stem/progenitor cells and endometrial pathologies in the context of this recently unravelled endometrial glandular organization.

SEARCH METHODS

An extensive literature search was conducted from inception to April 2021 using multiple databases, including PubMed/Web of Science/EMBASE/Scopus, to select studies using keywords applied to endometrial glandular anatomy and regeneration, and the references included in selected publications were also screened. All relevant publications were included.

OUTCOMES

The human endometrial glands have a unique and complex architecture; branched basalis glands proceed in a horizontal course adjacent to the myometrium, as opposed to the non-branching, vertically coiled functionalis glands, which run parallel to each other as is observed in intestinal crypts. This complex network of mycelium-like, interconnected basalis glands is demonstrated to contain endometrial epithelial stem cells giving rise to single, non-branching functionalis glands. Several previous studies that have tried to confirm the existence of epithelial stem cells have used methodologies that prevent sampling of the stem cell-rich basalis. More recent findings have provided insight into the efficient regeneration of the human endometrium, which is preferentially evolved in humans and menstruating upper-order primates.

WIDER IMPLICATIONS

The unique physiological organization of the human endometrial glandular element, its relevance to stem cell activity and scarless endometrial regeneration will inform reproductive biologists and clinicians to direct their future research to determine disease-specific alterations in glandular anatomy in a variety of endometrial pathological conditions.

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.

Integrating Network Pharmacology and Experimental Validation Deciphers the Mechanism of Guizhi Fuling Wan against Adenomyosis

Aim

This study aimed to predict the key targets and endocrine mechanisms of Guizhi Fuling Wan (GZFLW) in treating adenomyosis (AM) through network pharmacology, molecular docking, and animal experiment verification.

Methods

The related ingredients and targets of GZFLW in treating AM were screened out using TCMSP, BATMAN-TCM, SwissTargetPrediction, and PubChem Database. Then, the protein-protein interaction (PPI) analysis and the network of compound-hub targets were constructed. At the same time, the key targets were uploaded to the Metascape Database for KEGG pathway enrichment analysis. After that, the molecular docking technology of the main active components and hub targets was performed. Furthermore, animal experiments were used to verify the results of network pharmacology analysis.

Results

A total of 55 active ingredients of GZFLW and 44 overlapping targets of GZFLW in treating AM were obtained. After screening, 25 hub targets were collected, including ESR1, EGF, and EGFR. Then, the KEGG pathway enrichment analysis results indicated that the endocrine therapeutic mechanism of GZFLW against AM is mainly associated with the estrogen signaling pathway, endocrine resistance, and an EGFR tyrosine kinase signaling pathway. Then, molecular docking showed that the significant compounds of GZFLW had a strong binding ability with ERα and EGFR. More importantly, the animal experiments confirmed that the GZFLW could downregulate the abnormal infiltration of the endometrial epithelium into the myometrium and had no interference with the normal sexual cycle. This effect may be directly related to intervening the local estrogen signaling pathway of the endometrial myometrial interface (EMI). It may also be associated with the myometrium cells' estrogen resistance via GPER/EGFR signaling pathway.

Conclusion

The endocrine mechanism of GZFLW in treating AM was explored based on network pharmacology, molecular docking, and animal experiments, which provided a theoretical basis for the clinical application of GZFLW.

Endometriosis increases the rate of spontaneous early miscarriage in women who have adenomyosis lesions

RESEARCH QUESTION

In women with radiologically diagnosed adenomyosis, is the presence of endometriosis associated with a higher rate of miscarriage?

DESIGN

An observational cohort study of women who received medical care for benign gynaecological conditions between May 2005 and May 2018. Women who had adenomyosis lesions visualized by uterine magnetic resonance imaging (MRI) were included. Women who had never been pregnant were excluded. Women with adenomyosis identified by MRI but who did not have endometriosis lesions (control group) were compared with women with adenomyosis and endometriosis lesions (study group). Primary outcome was rate of a previous history of early miscarriage.

RESULTS

A total of 214 pregnancies in the study group and 53 pregnancies in the control group were analysed. The rate of a previous miscarriage was significantly higher among women with adenomyosis and endometriosis lesions compared with women in the control group (61/214 [28.5%] versus 6/53 [11.3%], respectively, P = 0.009). A multivariable generalized estimating equation logistic regression model, adjusted for adenomyosis and endometriosis phenotypes, found that the association between endometriosis and adenomyosis significantly increased the risk of miscarriage (OR 3.2, 95% CI 1.1 to 9.65). The risk was significantly higher with deep infiltrating endometriosis (OR 4.37, 95% CI 1.32 to 14.53).

CONCLUSIONS

Women affected by endometriosis had a significantly higher rate of previous spontaneous miscarriage than women without endometriosis with adenomyosis lesions identified by MRI. Mechanistic studies are needed to establish the complex link between the presence of endometriosis and adenomyosis and the rate of spontaneous miscarriage.

[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.

Clinicopathological characteristics and imaging findings to identify adenomyosis-related symptoms

PURPOSE

The study aims to identify the clinicopathological risk factors and magnetic resonance (MR) imaging findings for adenomyosis-related symptoms, including menorrhagia, dysmenorrhea, and infertility.

METHODS

This was an observation-based cross-sectional study using data from the adenomyosis cohort study. The authors evaluated the clinicopathological variables and various MR imaging findings.

RESULTS

Two hundred twenty patients with histologically confirmed adenomyosis were included in this study. Multivariate analysis showed that a middle/retroflexed uterus and adenomyosis lesions of 21 mm or more were significant independent predictors of dysmenorrhea. The history of dysmenorrhea and the maximum length from the cervix to the uterine fundus ≥103 mm were independent risk factors of menorrhagia. One of the key factors associated with non-infertility included the absence of deep infiltrating endometriosis (DIE) and/or superficial peritoneal disease (SUP).

CONCLUSIONS

This study identified clinicopathological risk factors and imaging findings associated with adenomyosis-related symptoms. The maximum length from the cervix to the uterine fundus and adenomyosis lesion thickness are independent predictors for the presence of menorrhagia and dysmenorrhea, respectively. Infertility may be associated with the coexistence of endometriosis rather than adenomyosis itself. This result is from an analysis of a small number of infertility patients and requires further study.

A Case of Elastography-Assisted Laparoscopic Fertility Preservation for Severe Deep Endometriosis Causing Ureteral Stenosis and Subtype II Adenomyosis

Adenomyosis is commonly treated by total hysterectomy. Adenomyomectomy is considered for women of reproductive age who wish to preserve their fertility. However, a high recurrence rate following adenomyomectomy has been reported because complete removal of the lesion is difficult, and uterine rupture during pregnancy remains a complication. We previously reported that laparoscopic adenomyomectomy using a cold knife prevented thermal damage to the myometrium and elastography to avoid residual lesions. Here, we report the case of a patient who underwent complete resection of a subtype II adenomyosis and resection of deep endometriosis (DE) with the closure of the pouch of Douglas. The patient was 31 years old, had severe dysmenorrhea, and had left ureteral stenosis and subtype II adenomyosis associated with the closure of the pouch of Douglas by the DE. After resection of the DE posterior wall adenomyosis, residual lesions were confirmed by laparoscopic real-time elastography. Eight weeks after surgery, postoperative transvaginal ultrasound showed that the myometrium had shrunk from 28 to 22.7 mm, and the hydronephrosis had disappeared, although a stent remained necessary. In this study, we report the complete resection of subtype II adenomyosis and DE, combined with elastography to visualize the lesions during resection.

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.

Effects of localisation of uterine adenomyosis on outcome of in vitro fertilisation/intracytoplasmic sperm injection fresh and frozen-thawed embryo transfer cycles: a multicentre retrospective cohort study

BACKGROUND

Uterine adenomyosis is a benign disease, common among women in their 40 and 50 s, characterised by ectopic endometrial tissue in the uterine myometrial layer. Adenomyosis causes infertility and has a negative effect on the outcomes of in vitro fertilisation (IVF)/intracytoplasmic sperm injection (ICSI) embryo transfer (ET) cycles. It has also been reported to have different characteristics depending on the adenomyotic lesion localisation. The effect of its localisation on IVF/ICSI-ET outcomes is unclear. This study aimed to investigate whether adenomyotic lesion localisation, assessed using magnetic resonance imaging (MRI), was associated with outcomes of IVF/ICSI-ET cycles.

METHODS

This multicentre, joint, retrospective cohort study analysed the medical records of 67 infertile patients with adenomyosis who underwent IVF/ICSI with fresh and frozen-thawed ET at five participating facilities from January 2012 to December 2016 and for whom MRI data were available. Fifteen patients were excluded; therefore, the MRI data of 52 patients were evaluated by two radiologists. We assessed the localisation of and classified adenomyotic lesions into advanced (invades the full thickness of the uterine myometrium), extrinsic (localised on the serosal side), and intrinsic (localised on the endometrial side) subtypes.

RESULTS

There were 40 advanced, nine extrinsic, and three intrinsic cases, and the outcomes of 100, 27, and nine ET cycles, respectively, were analysed. Pregnancy loss/clinical pregnancy and live birth rates of the advanced, extrinsic, and intrinsic groups were 64 % (16/25) and 9 % (9/100), 33.3 % (3/9) and 22.2 % (6/27), and 50 % (1/2) and 11.1 % (1/9), respectively. A logistic regression analysis adjusted for age, prior miscarriage, and body mass index showed that the extrinsic group had fewer pregnancy losses (odds ratio 0.06; 95 % confidence interval [CI]: 0.00-0.54, p = 0.026) and more live births (odds ratio 6.05; 95 % CI: 1.41-29.65, p = 0.018) than the advanced group.

CONCLUSIONS

Adenomyotic lesions exert different effects on IVF/ICSI-ET outcomes. Thus, MRI assessments of adenomyosis in infertile patients are beneficial. Establishment of treatment plans based on adenomyotic lesion localisation should be considered.

Adenomyosis of the inner and outer myometrium are associated with different clinical profiles

STUDY QUESTION

Do adenomyosis phenotypes such as external or internal adenomyosis, as diagnosed by MRI, have the same clinical characteristics?

SUMMARY ANSWER

External adenomyosis was found more often in young and nulliparous women and was associated with deep infiltrating endometriosis, whereas, in contrast, internal adenomyosis was more often associated with heavy menstrual bleeding (HMB) but no differences were noted in terms of pain symptoms.

WHAT IS KNOWN ALREADY

Adenomyosis is characterized by the presence of endometrial glands and stroma deep within the myometrium, giving rise to dysmenorrhea, pelvic pain and menorrhagia. Various forms have been described, including adenomyosis of the outer myometrium (external adenomyosis), which corresponds to lesions separated from the junctional zone (JZ), and adenomyosis of the inner myometrium (internal adenomyosis), which is mostly characterized by endometrial implants scattered throughout the myometrium and enlargement of the JZ. Although the pathogenesis of adenomyosis is not clearly understood, several lines of evidence suggest that these two phenotypes could have distinct origins. The clinical presentation of different forms of adenomyosis in patients warrants further investigation.

STUDY DESIGN, SIZE, DURATION

This was an observational study that used data collected prospectively in non-pregnant patients aged between 18 and 42 years who had undergone surgical exploration for benign gynecological conditions at our institution between May 2005 and May 2018. Only women with a pelvic MRI performed by a senior radiologist during the preoperative work-up were retained for this study. For each patient, a standardized questionnaire was completed during a face-to-face interview conducted by the surgeon in the month preceding the surgery. The women's histories (notably their age, gravidity, history of surgery and associated endometriosis), as well as clinical symptoms such as the pain intensity, presence of menorrhagia and infertility, were noted.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A pelvic MRI was performed in 496 women operated at our center for a benign gynecological disease who had provided signed informed consent. Of these, 248 women had a radiological diagnosis of adenomyosis. Based on the MRI findings, the women were diagnosed as having external and/or internal adenomyosis. The women were allocated to two groups according to the adenomyosis phenotype (only external adenomyosis vs only internal adenomyosis). Women exhibiting an association of both adenomyosis forms were analyzed separately.

MAIN RESULTS AND THE ROLE OF CHANCE

In all, following the MRI findings, 109 women (44.0%) exhibited only external adenomyosis, while 78 (31.5%) had only internal adenomyosis. The women with external adenomyosis were significantly younger (mean ± SD; 31.9 ± 4.6 vs 33.8 ± 5.2 years; P = 0.006), more often nulligravid (P ≤ 0.001) and more likely to exhibit an associated endometriosis (P < 0.001) compared to the women in the internal adenomyosis group. Moreover, the women exhibiting internal adenomyosis significantly more often had a history of previous uterine surgery (P = 0.002) and HMB (62 (80%) vs 58 (53.2%), P < 0.001) compared to the women with external adenomyosis. No differences in the pain scores (i.e. dysmenorrhea, non-cyclic pelvic pain and dyspareunia) were observed between the two groups.

LIMITATIONS, REASONS FOR CAUTION

The exclusive inclusion of surgical patients could constitute a possible selection bias, as the women referred to our center may have suffered from particularly severe clinical symptoms.

WIDER IMPLICATIONS OF THE FINDINGS

Further studies are needed to explore the pathogenesis by which these types of adenomyosis occur. This could help with the development of new treatment strategies specific for each entity.

STUDY FUNDING/COMPETING INTEREST(S)

none.

TRIAL REGISTRATION NUMBER

N/A.

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.

Adenomyosis is associated with specific proton nuclear magnetic resonance (1H-NMR) serum metabolic profiles

OBJECTIVE

To determine whether the adenomyosis phenotype affects the proton nuclear magnetic resonance (¹H-NMR)-based serum metabolic profile of patients.

DESIGN

Cohort study.

SETTING

University hospital-based research center.

PATIENTS

Seventy-seven patients who underwent laparoscopy for a benign gynecologic condition.

INTERVENTIONS

Pelvic magnetic resonance imaging and collection of a venous peripheral blood sample were performed during the preoperative workup. The women were allocated to the adenomyosis group (n = 32), or the control group (n = 45). The adenomyosis group was further subdivided into two groups: diffuse adenomyosis of the inner myometrium (n = 14) and focal adenomyosis of the outer myometrium (n = 18). Other adenomyosis phenotypes were excluded.

MAIN OUTCOME MEASURES

Metabolomic profiling based on ¹H-NMR spectroscopy in combination with statistical approaches.

RESULTS

The serum metabolic profiles of the patients with adenomyosis indicated lower concentrations of 3-hydroxybutyrate, glutamate, and serine compared with controls. Conversely, the concentrations of proline, choline, citrate, 2-hydroxybutyrate, and creatinine were higher in the adenomyosis group. The focal adenomyosis of the outer myometrium and the diffuse adenomyosis phenotypes also each exhibited a specific metabolic profile.

CONCLUSION

Serum metabolic changes were detected in women with features of adenomyosis compared with their disease-free counterparts, and a number of specific metabolic pathways appear to be engaged according to the adenomyosis phenotype. The metabolites with altered levels are particularly involved in immune activation as well as cell proliferation and cell migration. Nevertheless, this study did find evidence of a correlation between metabolite levels and symptoms thought to be related to adenomyosis. Further studies are required to determine the clinical significance of these differences in metabolic profiles.

WNK1 regulates uterine homeostasis and its ability to support pregnancy

WNK1 (with no lysine [K] kinase 1) is an atypical kinase protein ubiquitously expressed in humans and mice. A mutation in its encoding gene causes hypertension in humans, which is associated with abnormal ion homeostasis. WNK1 is critical for in vitro decidualization in human endometrial stromal cells, thereby demonstrating its importance in female reproduction. Using a mouse model, WNK1 was ablated in the female reproductive tract to define its in vivo role in uterine biology. Loss of WNK1 altered uterine morphology, causing endometrial epithelial hyperplasia, adenomyotic features, and a delay in embryo implantation, ultimately resulting in compromised fertility. Combining transcriptomic, proteomic, and interactomic analyses revealed a potentially novel regulatory pathway whereby WNK1 represses AKT phosphorylation through protein phosphatase 2A (PP2A) in endometrial cells from both humans and mice. We show that WNK1 interacted with PPP2R1A, the alpha isoform of the PP2A scaffold subunit. This maintained the levels of PP2A subunits and stabilized its activity, which then dephosphorylated AKT. Therefore, loss of WNK1 reduced PP2A activity, causing AKT hypersignaling. Using FOXO1 as a readout of AKT activity, we demonstrate that there was escalated FOXO1 phosphorylation and nuclear exclusion, leading to a disruption in the expression of genes that are crucial for embryo implantation.

Efficacy of the levonorgestrel-releasing intrauterine device is associated with different subtypes of adenomyosis: a retrospective study

Background

Although the levonorgestrel-releasing intrauterine device (LNG-IUD) has been widely applied in the treatment of adenomyosis, not all the patients are satisfied with its efficacy. The present retrospective study aimed to investigate the efficacy of LNG-IUD on different subtypes of adenomyosis.

Methods

The study comprised a cohort of 207 patients who received the LNG-IUD at the Women’s Hospital, Zhejiang University School of Medicine, China, from June 2013 to June 2016. Different subtypes of adenomyosis were classified by magnetic resonance imaging (MRI) and patients were subcategorized into three groups (subtype I: intrinsic, n=70; subtype II: extrinsic, n=73; subtype IV: indeterminate, n=64). Multiple variables were compared among the different groups.

Results

Patient demographics, clinical features and the treatment effects of the LNG-IUD were compared between the three subtype groups. The numeric rating scale (NRS) and pictorial blood loss assessment chart (PBAC) score markedly decreased after insertion of the LNG-IUD compared with baseline in all patients in the three subtype groups (P<0.001 for all groups). Compared to the other two subtypes, the efficacy rate was lower and the spontaneous expulsion rate was higher in subtype IV adenomyosis patients than that in other two groups (P<0.05). The independent factor associated with the spontaneous expulsion of the system was suggested to be uterine size before IUD placement and bleeding amount after LNG-IUD treatment in the subtype I [P=0.029, hazards ratio (HR): 3.37, 95% confidence interval (CI): 1.09–6.88] and IV (P=0.045, HR: 1.02, 95% CI: 1.01–1.21) adenomyosis patients respectively.

Conclusions

The LNG-IUD is proved to be an effective approach to treat subtype I and II adenomyosis. However, further study is warranted to explore a more suitable protocol to treat this subtype IV adenomyosis due to the high incidence of treatment failure and expulsion.

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.

Origin and Pathogenic Mechanisms of Uterine Adenomyosis: What Is Known So Far

Uterine adenomyosis is a benign disease, commonly encountered in reproductive-age women and responsible for chronic pelvic pain, abnormal uterine bleeding, and infertility. Although the exact origin and pathogenic mechanisms involved in adenomyosis still need to be elucidated, significant progress has been made over recent years. Ever since the theory of endometrium invaginating the myometrium via a traumatized interface was first proposed, numerous molecular mechanisms have been reported to participate in this process. At the same time, an alternative theory has suggested de novo development of adenomyotic lesions from metaplasia of Müllerian remnants or adult stem cells. Hence, our understanding of the pathogenesis of adenomyosis has been greatly enhanced and is anticipated to pave the way for development of an effective and safe treatment. The goal of this review is to analyze current knowledge on the origin and pathogenic mechanisms of adenomyosis, ranging from the most widely accepted theories to newly reported data.

Adenomyosis: Mechanisms and Pathogenesis

Adenomyosis is a common disorder of the uterus, and is associated with an enlarged uterus, heavy menstrual bleeding (HMB), pelvic pain, and infertility. It is characterized by endometrial epithelial cells and stromal fibroblasts abnormally found in the myometrium where they elicit hyperplasia and hypertrophy of surrounding smooth muscle cells. While both the mechanistic processes and the pathogenesis of adenomyosis are uncertain, several theories have been put forward addressing how this disease develops. These include intrinsic or induced (1) microtrauma of the endometrial-myometrial interface; (2) enhanced invasion of endometrium into myometrium; (3) metaplasia of stem cells in myometrium; (4) infiltration of endometrial cells in retrograde menstrual effluent into the uterine wall from the serosal side; (5) induction of adenomyotic lesions by aberrant local steroid and pituitary hormones; and (6) abnormal uterine development in response to genetic and epigenetic modifications. Dysmenorrhea, HMB, and infertility are likely results of inflammation, neurogenesis, angiogenesis, and contractile abnormalities in the endometrial and myometrial components. Elucidating mechanisms underlying the pathogenesis of adenomyosis raise possibilities to develop targeted therapies to ameliorate symptoms beyond the current agents that are largely ineffective. Herein, we address these possible etiologies and data that support underlying mechanisms.

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.

Relationship between adenomyosis and endometriosis; Different phenotypes of a single disease?

Adenomyosis and endometriosis are common gynecological disorders, but their pathophysiology is still under debate. The aim of this review is to discuss whether adenomyosis and endometriosis represent two different entities or different phenotypes of a single disease. We searched PubMed electronic databases published between January 2000 and April 2020. Endometriosis is classified into three phenotypes; superficial peritoneal disease (SUP), ovarian endometrioma (OMA) and deep infiltrating endometriosis (DIE) lesions. Adenomyosis presents several different subtypes, including intrinsic adenomyosis, extrinsic adenomyosis, adenomyosis externa and focal adenomyosis located in the outer myometrium (FAOM). Human uterus is embryologically composed of archimetra, originating from the Müllerian duct, and neometra, arising from the non-Müllerian duct, and adenomyosis and endometriosis are diseases of archimetra. The outer myometrial layer of the uterus is composed of highly differentiated smooth muscle cells (SMCs), while the inner myometrial cells are immature. Inappropriate uterine contractions can cause retrograde menstruation and chronic inflammation in the pelvic cavity, then influencing the development of pelvic endometriosis. Furthermore, hyperperistalsis results in physiological and pathological changes to the endometrial-myometrial junctional barrier, allowing invagination of the normal endometrial tissue into the inner myometrial layer. This can trigger the development of intrinsic adenomyosis. There are insufficient data available to draw conclusions, but extrinsic adenomyosis may result from pelvic endometriosis and FAOM from rectal and bladder DIE/adenomyosis externa. In conclusions, this paper contributes to the debate in the possibility that adenomyosis and endometriosis represent different phenotypes of a single disease.

Adenomyosis: Disease, uterine aging process leading to symptoms, or both?

For many decades adenomyosis has been a histological diagnosis in hysterectomy specimens. Traditionally, it has been considered a disease of late reproductive and premenopausal years causing uterine enlargement, dysmenorrhoea and menorrhagia. Recent advances in pelvic and uterine imaging techniques including transvaginal sonography and magnetic resonance imaging were responsible for a shift towards a non-invasive diagnosis and made a significant contribution to a better understanding of its pathogenesis, epidemiology, histological spectrum, and clinical symptomatology. With these non-invasive tools it has been shown that adenomyosis is probably a condition affecting much younger populations and is frequently asymptomatic at an early stage of its development. Regarding symptomatic disease, the distribution and extent of adenomyotic lesions do not correlate consistently with the various symptoms that are considered typical of adenomyosis. More importantly, accurate diagnosis of adenomyosis suffers from a lack of consensus among experts on imaging and even histological diagnostic criteria. Several pathogenetic theories have attempted to shed light on the establishment, evolution and distribution of adenomyotic lesions within the uterine wall, including the tissue injury and repair (TIAR) mechanism, metaplasia, and the more recent genetic-epigenetic theory. So far, none of these can adequately and independently explain the appearance of all types of adenomyosis. This review paper attempts a correlation between the proposed pathogenetic theories and the clinical and histological spectrum of adenomyosis, in an effort to give a plausible explanation of the evolution of this condition from an asymptomatic state to a disease, through synthesis of the existing data.

Exploring the challenges for a new classification of adenomyosis

The availability of non-invasive diagnostic tests is an important factor in the renewed interest in adenomyosis, as the disease can now be more accurately mapped in the uterus without a need for hysterectomy. An agreed system for classifying and reporting the condition will enhance our understanding of the disease and is envisaged to enable comparison of research studies and treatment outcomes. In this review, we assess previous and more recent attempts at producing a taxonomy, especially in view of the latest proposal for subdivision of adenomyosis into an internal and an external variant. In this context, we also explore the uncertainties linked to classifying involvement of the uterovesical pouch, the pouch of Douglas and lesions in the outer myometrium. Two opposing hypotheses are forwarded to explain the pathogenesis of these variants, namely that disease localized in these areas originates from an invasion by uterine adenomyosis of peritoneal organs; alternatively, that lesions present in the outer myometrium originate from peritoneal endometriosis. At the root of debates around these opposing theories of pathogenesis is fragmentary evidence. Because of the limitations of currently available evidence, and until this issue is resolved, broad agreement on a hypothesis to underpin any proposed classification is unlikely.

Expression of Cannabinoid Receptors in Myometrium and its Correlation With Dysmenorrhea in Adenomyosis

The myometrium, especially the junctional zone (JZ), is now well documented to have a role in the pathogenesis of adenomyosis. Cannabinoid receptors have been shown to participate in the establishment of endometriosis and its pain perception. However, its relation to adenomyosis has not been identified yet. The aim of this study was to investigate the expression of cannabinoid receptor type I (CB1) and type II (CB2) in myometrium of uteri with and without adenomyosis and determine the correlation between their levels and clinical parameters of adenomyosis. We collected tissue samples of JZ and the outer myometrium from 45 premenopausal women with adenomyosis and 34 women without adenomyosis. CB1 and CB2 messenger RNA (mRNA) and protein expression levels were evaluated by the use of Western blotting and real-time quantitative polymerase chain reaction from all samples. Clinical information on the severity of dysmenorrhea and other data were collected. We found both CB1 and CB2 mRNA and protein levels in women with adenomyosis were significantly higher than those of controls, and CB1 expression levels in JZ were positively correlated with the severity of dysmenorrhea. These data suggest that cannabinoid receptor CB1 may be involved in the pathogenesis of dysmenorrhea in adenomyosis and may be a potential therapeutic target.

Connective tissue growth factor mediates transforming growth factor β-induced collagen expression in human endometrial stromal cells

Background

Adenomyosis is a medical condition defined by the abnormal presence of endometrial tissue within the myometrium, in which fibrosis occurs with new collagen deposition and myofibroblast differentiation. In this study, the effect of several mediators and growth factors on collagen expression was investigated on human endometrial stromal cells (fibroblasts) derived from adenomyotic endometrium.

Experimental approach

RT-PCR, Western blot analysis, pharmacological interventions and siRNA interference were applied to primary cultured human endometrial stromal cells (fibroblasts). Immunohistochemistry was used to analyze protein expression in adenomyotic endometrium tissue specimens.

Results

Of the tested mediators, transforming growth factor β1 (TGFβ1) and its isoforms were effective to induce collagen and connective tissue growth factor (CTGF) expression. Collagen and CTGF induction by TGFβ1 could be reduced by the inhibitors targeting DNA transcription, protein translation, and Smad2/3 signaling. Interestingly, TGFβ1 induced Smad2/3 phosphorylation and CTGF mRNA expression, but not collagen mRNA expression, suggesting that TGFβ1 mediates collagen expression through CTGF induction and Smad2/3 activation. In parallel, TGFβ1 and CTGF also induced expression of heat shock protein (HSP) 47, a protein required for the synthesis of several types of collagens. However, only CTGF siRNA knockdown, could compromise TGFβ1-induced collagen expression. Finally, the immunohistochemistry revealed vimentin- and α-SMA-positive staining for (myo)fibroblasts, TGFβ1, collagen, and CTGF in the subepithelial stroma region of human adenomyotic endometria.

Conclusion and implications

We reveal here that TGFβ1, collagen, and CTGF are expressed in the stroma of adenomyotic endometria and demonstrate that TGFβ1 can induce collagen production in endometrium-derived fibroblasts through cellular Smad2/3-dependent signaling pathway and CTGF expression, suggesting that endometrial TGFβ may take part in the pathogenesis of adenomyosis and ectopic endometrium may participate in uterine adenomyosis.