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

Adenomyosis-A Call for Awareness, Early Detection, and Effective Treatment Strategies: A Narrative Review

OBJECTIVE

To provide a brief summary of the high incidence, symptomatology, different types, and diagnosis of adenomyosis and to explore various aspects of the disease, with the primary aim of raising awareness among gynecologists for appropriate and early detection.

BACKGROUND

Adenomyosis, a benign gynecological condition characterized by the infiltration of endometrial tissue into the myometrium, poses significant challenges to women's reproductive health.

METHODS

A narrative review was conducted by searching PubMed, Scopus, and Cochrane databases and offering a non-systematic summary and critical analysis of current knowledge on the impact of adenomyosis on women's health. Articles published in the English language up to May 2023, including original scientific papers, clinical trials, meta-analyses, and reviews focusing on various aspects of adenomyosis, were included in the synthesis of this review.

CONCLUSIONS

Approximately 20% of women are affected by adenomyosis, which manifests with various subtypes, distinct epidemiological profiles, symptomatology, and treatment responses. Despite its clinical significance, adenomyosis remains understudied, resulting in a significant disparity in research and the literature compared to other gynecological conditions. The severity of adenomyosis is compounded when coexisting with endometriosis, particularly deep-infiltrating endometriosis (DIE), leading to exacerbated fertility issues and severe symptomatology. The wide range of symptoms, including adverse pregnancy outcomes such as pre-eclampsia, highlights its wider impact and emphasizes the need for increased awareness of the condition. Adenomyosis is frequently associated with treatment failure in endometriosis, contributing to dienogest resistance, elevated discontinuation rates, and persistent pain post-endometriosis surgery. Additionally, the lack of specific treatments tailored to adenomyosis poses a considerable challenge in clinical management.

The pathogenesis of endometriosis and adenomyosis: insights from single-cell RNA sequencing†

Endometriosis and adenomyosis are two similar gynecological diseases that are characterized by ectopic implantation and the growth of the endometrial tissue. Previous studies have reported that they share a common pathophysiology in some respects, such as a similar cellular composition and resistance to the progestogen of lesions, but their underlying mechanisms remain elusive. Emerging single-cell ribonucleic acid sequencing (scRNA-seq) technologies allow for the dissection of single-cell transcriptome mapping to reveal the etiology of diseases at the level of the individual cell. In this review, we summarized the published findings in research on scRNA-seq regarding the cellular components and molecular profiles of diverse lesions. They show that epithelial cell clusters may be the vital progenitors of endometriosis and adenomyosis. Subclusters of stromal cells, such as endometrial mesenchymal stem cells and fibroblasts, are also involved in the occurrence of endometriosis and adenomyosis, respectively. Moreover, CD8+ T cells, natural killer cells, and macrophages exhibit a deficiency in clearing the ectopic endometrial cells in the immune microenvironment of endometriosis. It seems that the immune responses are activated in adenomyosis. Understanding the immune characteristics of adenomyosis still needs further exploration. Finally, we discuss the application of findings from scRNA-seq for clinical diagnosis and treatment. This review provides fresh insights into the pathogenesis of endometriosis and adenomyosis as well as the therapeutic targets at the cellular level.

Association between Uterine Adenomyosis and Infertility: Role of Axonemal Alteration in Apical Endometria

ABSTRACT

Uterine adenomyosis is an estrogen-dependent chronic inflammatory condition and may cause painful symptoms, abnormal uterine bleeding, and/or subfertility/infertility. It is characterized by the presence of endometrial glands and stroma within the myometrium causing enlargement of the uterus as a result of reactive hyperplastic and/or hypertrophic change of the surrounding myometrium. Similar to endometriosis, adenomyosis has a negative impact on female fertility. Abnormal uterotubal sperm transport, tissue inflammation, and the toxic effect of chemical mediators have been proposed as contributing factors. Inflammation-induced damage of the mucosal cilia in the fallopian tube has been reported. Besides other proposed mechanisms, our most recent study with transmission electron microscopy analysis indicated that microvilli damage and an axonemal alteration in the apical endometria occur in response to endometrial inflammation. This may be involved in the negative fertility outcome in women with adenomyosis. We present a critical analysis of the literature data concerning the mechanistic basis of infertility in women with adenomyosis and its impact on fertility outcome.

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.

Bowel wall thickness measured by MRI is useful for early diagnosis of bowel endometriosis

OBJECTIVE

To evaluate MRI features of bowel endometriosis (BE) and verify its clinical significance compared with pathological diagnosis.

MATERIALS AND METHODS

Since 2018, patients clinically diagnosed with deep endometriosis (DE) and planned to undergo surgery were enrolled prospectively. MRI parameters including traction, thickening sign of the rectum, obliteration of the Douglas Pouch, sign of adenomyosis, and pelvic adhesion were extracted. Uni- and multi-variate analyses were performed to explore their association with pathological diagnosis of BE. ROC curve was utilized to ascertain the appropriate cutoff value for predicting the presence and assessing the severity of BE.

RESULTS

A total of 226 patients with DE were recruited, and 154 BE cases were pathologically confirmed. Logistic regression analysis revealed that thickness of the rectal wall, traction sign of the rectum, and obliteration of the Douglas Pouch were independent factors to predict the presence of BE with the OR 1.59 (95% CI: 1.29-1.96), 0.24 (95% CI: 0.09-0.67), and 0.17 (95% CI: 0.07-0.40), respectively (p all < 0.01). A cutoff value of 6.0 mm for the thickness of rectal wall resulted in the highest predictive value of BE (specificity: 90.3%; sensitivity: 78.6%). For patients with measured thickness of the rectal wall over 6.0 mm, 72.1% (93/129) was confirmed BE with lesions infiltrated more than muscular layer.

CONCLUSION

This prospective study indicates that based on precise definition of visualized features on MRI images, BE could be recognized pre-operatively. DE patients with thickness of rectal wall exceeding 6.0 mm have a greater probability of BE.

CLINICAL RELEVANCE STATEMENT

Based on precise definition of visualized features and accurate measurement on MRI images, bowel infiltrating among deep endometriosis patients could be recognized pre-operatively.

KEY POINTS

• Precise definition of measurable MRI parameters made it possible for early detection of bowel endometriosis. • Thickening sign, traction sign of the rectum, and obliteration of the Douglas Pouch were typical radiological indicators for bowel endometriosis. • Bowel involvement is more sensitive to be detected among pelvic deep endometriosis patients with the thickness of the rectal wall over 6.0 mm.

Differences in the incidence of obstetric complications depending on the extent and location of adenomyosis lesions

OBJECTIVES

Although adenomyosis is reportedly associated with adverse pregnancy outcomes, clinical factors related to the high risk of obstetric complications are unclear. This study aimed to elucidate the characteristics of adenomyosis lesions associated with the increased incidence of obstetric complications based on imaging findings.

METHODS

This was a retrospective, observational cohort study conducted in a tertiary perinatal care center. Eighty-eight singleton pregnant women with adenomyosis were included in the study. Based on magnetic resonance imaging or ultrasonography before and/or during pregnancy, patients were classified according to three types of image characteristics: the extent of adenomyosis lesion (focal type or diffuse type), location of the lesion (extrinsic type, intrinsic type, or indeterminate type), the positional relationship between the lesion and the placenta (placenta distant from adenomyosis or placenta over adenomyosis), and the incidence of obstetric complications were examined.

RESULTS

Patients with diffuse type adenomyosis are significantly more likely to have spontaneous second-trimester miscarriage (diffuse type vs. focal type: 16.7 vs. 0%, p < .01), preterm premature rupture of membranes (19.4 vs. 1.9%, p < .01), and preeclampsia (25.0 vs. 7.7%, p = .02), as compared to those with focal type adenomyosis. In a comparison of the three location types, the incidence of placental malposition was higher in patients with the extrinsic type adenomyosis (extrinsic type vs. intrinsic type vs. indeterminate type: 20.0 vs. 6.7 vs. 2.3%, p = .03). Comparisons between the types of the placenta over or distant from adenomyosis lesion displayed no significant differences in the frequencies of obstetric complications.

CONCLUSIONS

We demonstrated that the frequency of obstetric complications related to adenomyosis varies depending on the extent and location of the lesion; patients with diffuse type adenomyosis have an increased risk of spontaneous second-trimester miscarriage, preterm premature rupture of membranes, and preeclampsia, while patients with extrinsic type adenomyosis have an increased risk of placental malposition. Imaging evaluation of adenomyosis prior to conception or early in pregnancy may be useful for the obstetrical risk assessment among patients with adenomyosis.

Pregnancy outcomes of adenomyotic patients with primary infertility after high-intensity focused ultrasound treatment

OBJECTIVE

To evaluate the therapeutic effect of high-intensity focused ultrasound (HIFU) treatment for adenomyotic patients with primary infertility and to explore the factors that affect the pregnancy outcomes.

MATERIALS AND METHODS

Twenty-seven adenomyotic patients with primary infertility who underwent HIFU at HUNAN Provincial Maternal and Child Health Care Hospital, China, between July 2018 and December 2022 were retrospectively reviewed. We evaluated the pregnancy outcomes and analyzed the factors that may affect pregnancy outcomes including time to conception, pregnancy approach, gestational age, delivery mode, neonatal outcomes, and complications during pregnancy and delivery.

RESULTS

Among the 27 adenomyotic patients with primary infertility, 10 patients had a total of 11 pregnancies after HIFU treatment. Of these, eight (72%) cases were natural pregnancies and three (23%) were in vitro fertilization (IVF) pregnancies. The median time to conception was 10 (range 4-25) months. There were eight (72%) successful deliveries. The rate of full-term deliveries was 90%. Of the eight live births, four (50%) were born vaginally and four (50%) by cesarean section. No severe complications occurred. The mean birth weight of newborns was 3.1 (range: 2.3-3.9) kg; all newborns developed well without complications during postpartum and breastfeeding.

CONCLUSIONS

HIFU treatment for adenomyosis could improve fertility of patients with primary infertility. HIFU is a promising therapeutic approach for patients with adenomyosis and infertility who wish to achieve pregnancy and have live birth deliveries.

Effects of localization of uterine adenomyosis on clinical features and pregnancy outcome

The purpose of this study was to implore the association among clinical features, long-term fertility outcomes and the anatomical location of adenomyosis identified by ultrasound. We collected data of non-pregnant patients between 20 and 40 years old who had undergone surgical exploration for benign gynecological conditions at our institution between January 2010 and December 2017. A total of 158 women met the inclusion criteria and were allocated into three groups according to the ultrasound-determined adenomyosis anatomical location: anterior (Group A), posterior (Group B), both posterior and anterior (Group C). 44.3% (70/158) adenomyosis was located at the posterior side. History of miscarriage and parity were significantly higher in Group C (p = 0.036 and 0.001 respectively). Group C also had a higher concurrence rate of ovarian endometrioma (OEM) (80.4%, p = 0.002), pelvic adhesion (80.4%, P = 0.003) and the revised American Fertility Society (rAFS) Score (median64, range2-100, P < 0.001), while a significantly lower rate of concurrent peritoneal endometriosis (P = 0.01). Group B showed a relative higher rate of coexistent heavy menstrual bleeding (28.6%, p = 0.04) and oviduct obstruction (24.3%, P = 0.038). Group A had a higher proportion of coexistent leiomyoma (53.1%, P = 0.002). There were no significant differences between group A, B, and C in terms of pain symptoms, endometrial polyps, operation time, and endometriosis fertility index score and other basic characters (p > 0.05). During the follow-up, 59.2% (61/103) patients had clinical pregnancies, and 26.2% (16/61) of them experienced pregnancy loss. Total in vitro fertilization and embryo transfer pregnancy rate was 64.6% (42/65) and spontaneous pregnancy rate was 50.0% (19/38). The Kaplan-Meier curves demonstrated significant lower cumulative pregnancy rate in Group C than Group A and Group B (p = 0.01). Severe obstetric complications such as placenta previa, placenta accreta, preeclampsia, and preterm birth were only found in women with adenomyosis located in the posterior side. In conclusion, types of adenomyosis based on sonographic location had different clinical features and pregnancy outcome. Patients with adenomyosis lesion in both anterior and posterior sides had higher combination of OEM, pelvic adhesion and rAFS score.

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.

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.

Comparison of high-intensity focused ultrasound for the treatment of internal and external adenomyosis based on magnetic resonance imaging classification

OBJECTIVE

To compare the safety and efficacy of high-intensity focused ultrasound (HIFU) treatment for patients with internal or external adenomyosis based on magnetic resonance imaging (MRI) classification.

MATERIALS AND METHODS

A total of 238 patients with internal adenomyosis and 167 patients with external adenomyosis who received HIFU treatment were enrolled. HIFU treatment results and adverse effects between patients with internal and external adenomyosis were compared.

RESULTS

The treatment time and sonication time for patients with external adenomyosis were significantly longer than that for patients with internal adenomyosis. The total energy used and EEF for patients with external adenomyosis were higher than that for patients with internal adenomyosis (p < 0.05). The pre-HIFU median dysmenorrhea score in patients with internal or external adenomyosis was 5 or 8 points, the median score decreased to 1 or 3 points in these two groups at 18-month post-HIFU (p < 0.05). The relief rate of dysmenorrhea was 79.5% in patients with internal adenomyosis, and it was 80.8% in patients with external adenomyosis. The pre-HIFU median menorrhagia score in patients with internal or external adenomyosis was 4 or 3 points, the median score decreased to 1 point in both groups at 18-month post-HIFU with a relief rate of 86.2% and 77.1%, respectively (p = 0.030). No serious complication occurred in any of these patients.

CONCLUSIONS

HIFU is a safe and effective treatment either for patients with internal adenomyosis or external adenomyosis. It seemed that internal adenomyosis is easier to be treated with HIFU and with a higher relief rate of menorrhagia than external 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.

Application of modified subtotal resection of adenomyosis combined with LNG-IUS and GnRH-a sequential therapy in severe adenomyosis: A case series

Background and Objective

Adenomyosis focus resection has always been the main surgical method for patients with uterine preservation, but its curative effect and surgical method are still controversial. We improved this method on the basis of the “double-flap method” and combined it with the levonorgestrel intrauterine delivery system (LNG-IUS) and gonadotropin-releasing hormone agonist (GnRH-a) sequential treatment to determine the clinical effect and feasibility of this scheme in the treatment of severe adenomyosis.

Methods

This is a retrospective review. A total of 64 patients with severe adenomyosis were treated in the Department of Gynecology of Changzhou Second People's Hospital, which is affiliated to Nanjing Medical University, from December 2017 to September 2021. The transabdominal approach and laparoscopic approach were adopted for the purposes of treatment in this study. Hence, the patients were subdivided into the transabdominal approach subgroup and the laparoscopic approach subgroup. The hemoglobin, visual analog score (VAS) score, menstruation score, and other indices of each patient before and after treatment were observed, recorded, and analyzed.

Results

All 64 patients underwent the operation successfully. After the completion of sequential treatment, the CA125 decreased significantly 1 month after the operation, the average uterine volume significantly reduced, the hemoglobin value increased to a certain extent 3 months after the operation, and the menstrual score and dysmenorrhea during the first menstruation were significantly lower than they were before the operation. After the treatment, the therapeutic results of the transabdominal approach subgroup and endoscopic approach subgroup were compared on the basis of the observed indices, and no significant difference was observed (P > 0.05). Only one patient had a downward movement of the LNG-IUS, and the vaginal ultrasound showed that the upper end of the LNG-IUS was approximately 1.5 cm from the bottom of the uterine cavity. The average follow-up period was 24.02 ± 11.77 months, and no lesion progression was found in any patients.

Conclusion

For patients suffering from severe adenomyosis who have no pregnancy plans and require uterine preservation, transabdominal or laparoscopic subtotal resection of the focus of adenomyosis, combined with the LNG-IUS + GnRH-a sequential treatment, may be a safe and effective alternative when conservative treatments such as drugs fail.

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

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

Unveiling the Pathogenesis of Adenomyosis through Animal Models

Background: Adenomyosis is a common gynecological disorder traditionally viewed as “elusive”. Several excellent review papers have been published fairly recently on its pathogenesis, and several theories have been proposed. However, the falsifiability, explanatory power, and predictivity of these theories are often overlooked. Since adenomyosis can occur spontaneously in rodents and many other species, the animal models may help us unveil the pathogenesis of adenomyosis. This review critically tallies experimentally induced models published so far, with a particular focus on their relevance to epidemiological findings, their possible mechanisms of action, and their explanatory and predictive power. Methods: PubMed was exhaustively searched using the phrase “adenomyosis and animal model”, “adenomyosis and experimental model”, “adenomyosis and mouse”, and “adenomyosis and rat”, and the resultant papers were retrieved, carefully read, and the resultant information distilled. All the retrieved papers were then reviewed in a narrative manner. Results: Among all published animal models of adenomyosis, the mouse model of adenomyosis induced by endometrial–myometrial interface disruption (EMID) seems to satisfy the requirements of falsifiability and has the predictive capability and also Hill’s causality criteria. Other theories only partially satisfy Hill’s criteria of causality. In particular, animal models of adenomyosis induced by hyperestrogenism, hyperprolactinemia, or long-term exposure to progestogens without much epidemiological documentation and adenomyosis is usually not the exclusive uterine pathology consequent to those induction procedures. Regardless, uterine disruption appears to be a necessary but not sufficient condition for causing adenomyosis. Conclusions: EMID is, however, unlikely the sole cause for adenomyosis. Future studies, including animal studies, are warranted to understand how and why in utero and/or prenatal exposure to elevated levels of estrogen or estrogenic compounds increases the risk of developing adenomyosis in adulthood, to elucidate whether prolactin plays any role in its pathogenesis, and to identify sufficient condition(s) that cause adenomyosis.

Extrinsic Adenomyosis Is Associated With Postoperative Recurrence of Ovarian Endometrioma

Objective: To determine whether endometrioma recurrence is closely related to the presence of extrinsic adenomyosis, which was demonstrated by magnetic resonance imaging (MRI). Design: Observational crosssectional study involving patients with the recurrence of ovarian endometrioma (OMA). Correlations of endometrioma recurrence and adenomyosis subtypes shown by MRI were analyzed. Method: Between January 2018 and December 2020, a total of 233 patients with recurrence of OMA after ovarian cystectomy were administered for surgery at our institution. All patients were divided into subtype II (Group A), subtype I+IV (Group B), and nonadenomyosis (Group C) groups at preoperative MRI imaging. The correlations of endometrioma recurrence with clinical features, imaging appearance, and surgical findings were retrospectively analyzed. Results: We found 112 (48.07%) patients of endometrioma recurrence combined with subtype II adenomyosis, 8 (3.43%) subtype I adenomyosis, 47 (20.17%) subtype IV adenomyosis, 66 (28.32%) nonadenomyosis. The mean time of OMA recurrence (44.28 ± 8.37, vs. 63.96 ± 10.28, vs. 69.36 ± 9.34 mon), rate of pain symptoms (85.71, vs. 69.10, vs. 18.18%), and primary infertility (31.25, vs. 14.55, vs. 10.77%) were higher in Group A. Uterine volume (257.37± 42.61, vs. 203.14 ± 33.52, vs. 100.85 ± 26.67 cm³), and mean OMA size (4.97 ± 2.25, vs. 4.36 ± 2.38, vs. 4.46 ± 2.70 cm) were significantly larger in Group A. The rate of DIE (83.93, vs. 45.45, vs. 40.91%), the number of DIE (3.6 ± 1.8 vs. 2.3 ± 1.5 vs. 2.2 ± 1.3), the mean total revised American Society for Reproductive Medicine score (rASRM, 103.14 ± 23.89 vs. 74.23 ± 16.72 vs. 36.51 ± 14.23) were significantly higher in Group A. After a multiple logistic regression analysis, extrinsic adenomyosis (OR 2.5, 95% CI 1.2-3.4), DIE lesions (OR 2.1, 95% CI 1.4-2.8), and primary infertility (OR 1.8, 95% CI 1.3-4.3) were significantly associated with early recurrence (in 3-year) of OMA. Conclusions: Extrinsic adenomyosis was associated with postoperative recurrence of OMA. In addition, a pathogenic link between extrinsic adenomyosis and pelvic endometriosis needs to be clarified.

Occurrence of chronic endometritis in different types of human adenomyosis

Purpose

Human adenomyosis has an adverse effect on female fertility. Exact mechanistic basis is still unclear. We investigated the occurrence of chronic endometritis (CE) in different types of human adenomyosis.

Methods

This is a prospective non-randomized observational study enrolling patients with focal (n = 30), diffuse (n = 26), intrinsic (n = 23), and extrinsic (n = 10) adenomyosis. Endometrial biopsy samples were collected from hysterectomy specimens. Immunohistochemical analysis was performed using antibody against CD68 (Mφ marker) with biopsy samples of intrinsic/extrinsic adenomyosis and CD138 (Syndecan-1), a marker of plasma cells, in all biopsy samples.

Results

In GnRHa-untreated groups, a higher trend in the occurrence of CE, as characterized by infiltration of ≥1 plasma cells in endometrial stroma, was found in women with focal (58.8%, p = 0.0849) and diffuse adenomyosis (60.0%, p = 0.0841) comparing to control women (10.0%). In women with focal adenomyosis, ipsilateral side showed a significantly higher occurrence of CE (58.8%) than on the contralateral side (11.7%) (p = 0.043). Tissue infiltration of macrophages in endometria was significantly higher in intrinsic than in extrinsic adenomyosis (p = 0.03) without showing any significant difference in the occurrence of CE between these two variants of adenomyosis.

Conclusion

A variable occurrence of CE in different types of adenomyosis may be involved in adverse reproductive outcome.

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.

A Comparison of Shear Wave Elastography between Normal Myometrium, Uterine Fibroids, and Adenomyosis: A Cross-Sectional Study

Background

The differential diagnosis between uterine fibroid and adenomyosis is sometimes difficult; a precise diagnosis is required in women with infertility because of the different choice of treatments. Ultrasound elastography (UE) is a novel technique to evaluate the elasticity or the stiffness of the tissue of interest. The present study aims to compare UE shear wave velocity (SWV) among normal uterine myometrium, uterine fibroid, and adenomyosis, and assess the accuracy of shear wave elastography in the diagnosis of adenomyosis.

Materials and Methods

This cross-sectional study recruited 25 subjects for each group (control, adenomyosis, and fibroid) from April 2019 to April 2020. Transvaginal UE using an Aplio 500 (Toshiba Medical Systems, Japan) with ultrasound mapping for point of tissue biopsy was performed for all subjects. The diagnosis was confirmed by histology. Masson’s trichrome staining for collagen was performed and quantified

Results

The mean ± standard deviation (SD) for SWV was 3.44 ± 0.95 m/seconds (control group), 4.63 ± 1.45 m/seconds (adenomyosis group), and 4.53 ± 1.07 m/seconds (fibroid group). The mean SWV differed when comparing normal myometrium and adenomyosis after adjustments for age and endometrial pathology (P=0.019). The cut-off point of SWV at 3.465 m/seconds could differentiate adenomyosis from the normal uterus with an 80% sensitivity, 80% specificity, and an area under the curve (AUC) of 0.80 (95% confidence interval [CI]: 0.68-0.93) (P<0.001). No significant difference in SWV between the adenomyosis and fibroid groups was detected.

Conclusion

Shear wave elastography could be an alternative tool to distinguish between normal myometrium and adenomyosis; however, it could not differentiate adenomyosis from uterine fibroid or uterine fibroid from normal myometrium.

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.

[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.

Uterine Adenomyosis: From Disease Pathogenesis to a New Medical Approach Using GnRH Antagonists

Uterine adenomyosis is a common chronic disorder frequently encountered in reproductive-age women, causing heavy menstrual bleeding, intense pelvic pain, and infertility. Despite its high prevalence, its etiopathogenesis is not yet fully understood, so there are currently no specific drugs to treat the disease. A number of dysregulated mechanisms are believed to contribute to adenomyosis development and symptoms, including sex steroid signaling, endometrial proliferation and invasiveness, and aberrant immune response. Abnormal sex steroid signaling, particularly hyperestrogenism and subsequent progesterone resistance, are known to play a pivotal role in its pathogenesis, which is why various antiestrogenic agents have been used to manage adenomyosis-related symptoms. Among them, gonadotropin-releasing hormone (GnRH) antagonists are swiftly gaining ground, with recent studies reporting efficient lesion regression and symptom alleviation. The aim of the present review is to compile available information on the pathogenesis of adenomyosis, explore the etiology and mechanisms of hyperestrogenism, and discuss the potential of antiestrogenic therapies for treating the disease and improving patient quality of life.

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.

Role of inflammation in benign gynecologic disorders: from pathogenesis to novel therapies†

Emerging evidence supports the notion that inflammation fosters the development of common benign gynecologic disorders, including uterine leiomyoma, endometriosis, and adenomyosis. Numerous cytokines, chemokines, and growth and transcription factors have indisputable roles in the establishment and maintenance of benign gynecologic disorders by initiating complex cascades that promote proliferation, angiogenesis, and lesion progression. The interaction between inflammation and benign gynecologic disorders is orchestrated by a plethora of factors, including sex steroids, genetics, epigenetics, extracellular matrix, stem cells, cardiometabolic risk factors, diet, vitamin D, and the immune system. The role of inflammation in these disorders is not limited to local pathobiology but also extends to involve clinical sequelae that range from those confined to the reproductive tract, such as infertility and gynecologic malignancies, to systemic complications such as cardiovascular disease. Enhanced understanding of the intricate mechanisms of this association will introduce us to unvisited pathophysiological perspectives and guide future diagnostic and therapeutic implications aimed at reducing the burden of these disorders. Utilization of inflammatory markers, microRNA, and molecular imaging as diagnostic adjuncts may be valuable, noninvasive techniques for prompt detection of benign gynecologic disorders. Further, use of novel as well as previously established therapeutics, such as immunomodulators, hormonal treatments, cardiometabolic medications, and cyclooxygenase-2 and NF-κB inhibitors, can target inflammatory pathways involved in their pathogenesis. In this comprehensive review, we aim to dissect the existing literature on the role of inflammation in benign gynecologic disorders, including the proposed underlying mechanisms and complex interactions, its contribution to clinical sequelae, and the clinical implications this role entails.

Proposal for developing treatment algorithms of women with symptomatic adenomyosis: A single-center experience

AIMS

The most common symptoms of adenomyosis include heavy menstrual bleeding and dysmenorrhea. A variety of medical or surgical techniques are utilized for the treatment of adenomyosis, but there are currently no specific treatment guidelines and best practice recommendations for management. The aim of this study is to summarize current treatment strategies for women with symptomatic adenomyosis in a single-center university hospital in order to provide reliable information for developing treatment algorithms.

METHODS

We conducted an observational cross-sectional study using data from the adenomyosis cohort study from January 2008 to December 2020. Detailed information, including demographic, clinicopathological, and imaging data, were collected from 220 pathologically confirmed patients with adenomyosis.

RESULTS

First, we identified clinical and imaging characteristics in women who underwent surgery or hormone therapy, especially dienogest (DNG) treatment, as first-line treatment. Surgery was generally recommended for multiparous women over the age of 43, especially for patients with intrinsic adenomyosis. Next, we identified the parameters that allowed the continuation of DNG treatment. Oral DNG was given to certain patients with a myometrium thickness of 35 mm or greater and coexisting with endometriosis and/or uterine fibroids. To prevent serious bleeding, DNG treatment can be limited to women with extrinsic adenomyosis with a uterine length of 125 mm or less.

DISCUSSION

Our findings may provide useful information in developing an evidence-based treatment guideline for patients with symptomatic adenomyosis, nevertheless, further investigation is needed for the validation of treatment algorithms.

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.

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.

Expression profiles of E/P receptors and fibrosis in GnRHa-treated and -untreated women with different uterine leiomyomas

Differential expressions of estrogen/progesterone receptors (ER/PR) and individual component of extracellular matrices derived from fibroid are reported. Information on the pattern of change in ER/PR expression and amount of tissue fibrosis after hormonal treatment is unclear. We investigated pattern of change in ER/PR expression and percentage of tissue fibrosis in different uterine leiomyomas after gonadotropin-releasing hormone agonist (GnRHa) treatment. Biopsy specimens from fibroids and adjacent myometria were collected after surgery from women with submucosal myoma (SMM, n = 18), intramural myoma (IMM, n = 16) and subserosal myoma (SSM, n = 17). A proportion of women in each group of fibroid underwent treatment with GnRHa for a variable period of 3-6 months. Tissue expression of ER and PR was analyzed by immunohistochemistry. In vitro cell proliferation effect of GnRHa on human umbilical vein endothelial cells (HUVECs) was examined. Distribution of tissue fibrosis was examined by Masson's trichrome staining with computer-captured image analysis of fibrosis derived from different types of fibroid. PR content was significantly higher than ER in tissues derived from GnRHa-untreated women with SMM and SSM (p = 0.04 for both). Comparing to untreated group, GnRHa-treatment significantly decreased either ER or PR expression in different fibroids. Exogenous treatment with GnRHa dose-dependently decreased proliferation of HUVECs. No significant difference was observed in the percentage of fibrosis in tissues collected from GnRHa-treated and -untreated women with fibroids. The distribution of fibrosis in myoma/myometria and occurrence of fibrosis in perivascular area showed an increasing trend with higher age of the women and with larger size of fibroids. Our findings suggest that despite estrogen dependency, higher PR content in GnRHa-untreated group may indicate a potential role of progesterone in leiomyoma growth. Although GnRHa therapy may shrink fibroids and reduce risk of bleeding during surgery, the occurrence of diffuse tissue fibrosis may impair effective reduction of fibroid size after hormonal treatment.

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.

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.

Focal adenomyosis of the outer myometrium and deep infiltrating endometriosis severity

OBJECTIVE

To determine whether the presence of focal adenomyosis of the outer myometrium (FAOM) at preoperative magnetic resonance imaging is associated with the severity of deep infiltrating endometriosis.

DESIGN

Observational cross-sectional study involving 255 symptomatic deep infiltrating endometriosis patients. Comparisons were performed according to the presence of FAOM.

SETTING

University hospital.

PATIENT(S)

Women with a preoperative magnetic resonance imaging and complete surgical exeresis of endometriotic lesions with histologically documented deep infiltrating endometriosis.

INTERVENTION(S)

Surgical management for deep infiltrating endometriosis.

MAIN OUTCOME MEASURE(S)

The presence of multiple deep infiltrating endometriosis lesions, the mean number and location of deep infiltrating endometriosis lesions, and the mean total revised American Society for Reproductive Medicine scores.

RESULT(S)

The prevalence of FAOM at preoperative magnetic resonance imaging in the 255 patients with deep infiltrating endometriosis was 56.5%. The mean number of deep infiltrating endometriosis lesions was significantly higher in the FAOM(+) group than in the FAOM(-) group: 3.5 ± 2.1 vs. 2.2 ± 1.5. The mean total revised American Society for Reproductive Medicine score was higher in case of FOAM coexisting with deep infiltrating endometriosis. After adjusting for confounding factors, the presence of FAOM was significantly associated with multiple deep lesions.

CONCLUSION(S)

FAOM was significantly associated with greater deep infiltrating endometriosis severity. This needs to be integrated into the management strategy. Furthermore, a pathogenic link between deep infiltrating endometriosis and FAOM cannot be excluded.

Pathogenesis of bowel endometriosis

The pathogenesis of bowel endometriosis is multifactorial. There is a predilection for disease of the rectum/sigmoid colon because refluxed endometrium is more likely to settle in the pouch of Douglas and its movement is delimited by the sigmoid colon, in addition to the close proximity of the rectum/sigmoid to posterior extrinsic uterine adenomyosis and to ovarian endometriomas. Once situated, deep bowel endometriosis has features of invasion, angiogenesis, and fibrosis (repeated tissue injury and repair), with emerging research on oxidative stress and the microbiome. Furthermore, deep bowel endometriosis is associated with neurogenesis and/or the recruitment of local nerve fibers and is capable of invading existing nerves, which in turn may also promote fibrosis. Recently, somatic cancer driver mutations (e.g., in KRAS) were identified in deep bowel endometriosis, which may play a role in the genetic/epigenetic theory of endometriosis. In the future, it is possible that bowel endometriosis could be classified based on molecular features.

Pathology and Pathogenesis of Adenomyosis

Adenomyosis represents a unique pathophysiological condition in which normal-appearing endometrial mucosa resides within myometrium and is thus protected from menstrual shedding. The resulting ectopic presence of endometrial tissue composed of glands and stroma is thought to affect normal contractile function and peristalsis of uterine smooth muscle, causing menometrorrhagia, infertility, and adverse obstetric outcomes. Since the first description of adenomyosis more than 150 years ago, pathologists have studied this lesion by examining tissue specimens, and have proposed multiple explanations to account for its pathogenesis. However, as compared with endometriosis, progress of adenomyosis research has been, at best, incremental mainly due to the lack of standardized protocols in sampling tissue and a lack of consensus diagnostic criteria in pathology practice. Despite these limitations, recent advances in revealing the detailed anatomy and biology of eutopic endometrium offer an unprecedented opportunity to study this common but relatively understudied disorder. Here, we briefly summarize the pathological aspects of adenomyosis from an historical background, and discuss conventional morphology and recent tissue-based molecular studies with a special emphasis on elucidating its tissue of origin from a pathologist's perspective. We also discuss unmet needs in pathology studies that would be important for advancing adenomyosis research.

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.