Two- and three-dimensional ultrasonographic features related to histopathology of the uterine endometrial-myometrial junctional zone

Junctional zone thickening: an endo-myometrial unit disorder

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

Endometrial receptivity in adenomyosis and/or endometriosis

A narrative review of endometrial receptivity in adenomyosis and/or endometriosis revealed that this parameter is difficult to assess in natural conception because both disorders alter natural fertility. Recent data emanating from assisted reproductive technology have allowed the study of endometrial receptivity in women affected by adenomyosis and endometriosis. This has upended our views on the effects of these 2 disorders on embryo implantation. Today, the very existence of altered receptivity in assisted reproductive technology is questioned. In this context, we now know that frozen euploid blastocyst transfers in estradiol and progesterone cycles have unaltered outcomes in both adenomyosis and endometriosis.

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.

Value of Transabdominal Combined Transvaginal Color Doppler Ultrasonography in the Distinguish between Uterine Adenomyoma and Uterine Fibroids

Objective. To investigate the value of transabdominal combined transvaginal color Doppler ultrasonography in the diagnosis of uterine adenomyoma. Methods. A total of 80 patients with suspected uterine adenomyoma in our hospital from January 2019 to December 2021 were selected as the study subjects. All of them were examined by transabdominal color Doppler ultrasound (TA-CDUS) and transvaginal color Doppler ultrasound (TV-CDUS), and the postoperative pathological examination results were taken as the gold standard to analyze the diagnostic efficacy of different examination methods for uterine adenomyoma. Results. By postoperative pathological biopsy, 46 cases (57.50%) were diagnosed as positive and 34 cases (42.50%) were diagnosed as negative, including 29 cases of uterine adenomyoma and 5 other cases. The sensitivity, accuracy, and negative predictive value of TA-CDUS combined with TV-CDUS in the diagnosis of adenomyoma were higher than those of TA-CDUS ( $P<0.05$ ), and the Kappa value between TA-CDUS and pathological diagnosis was 0.923, which was higher than the 0.615 between TV-CDUS and pathological diagnosis. TA-CDUS combined with TV-CDUS showed that there were significant differences in the distribution of Adier blood flow grades between patients with uterine adenomyoma and uterine fibroids ( $P<0.05$ ), and the Adier blood flow grades of patients with uterine adenomyoma were mainly grade 0 and grade I; and the resistance index (RI), peak systolic velocity (Vs), and pulsatile index (PI) in patients with uterine adenomyoma were higher than those in patients with uterine fibroids ( $P<0.05$ ). Conclusion. Compared with TA-CDUS, TA-CDUS combined with TV-CDUS is more sensitive and accurate in the diagnosis of uterine adenomyoma and has a good consistency with pathological diagnosis results. Attention should be paid to the blood flow parameter values in the differential diagnosis of uterine fibroids.

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.

Sonographic Signs of Adenomyosis in Women with Endometriosis Are Associated with Infertility

We compared the prevalence of ultrasound signs of adenomyosis in women with endometriosis who underwent surgery to those who were managed conservatively. This was a retrospective study of women evaluated at a tertiary endometriosis referral center who underwent 2D/3D transvaginal ultrasound. Adenomyosis diagnosis was based on the presence of at least three sonographic signs. The study group subsequently underwent laparoscopic surgery while the control group continued conservative management. Statistical analysis compared the two groups for demographics, symptoms, clinical data, and sonographic findings. The study and control groups included 244 and 158 women, respectively. The presence of any, 3+, or 5+ sonographic signs of adenomyosis was significantly more prevalent in the study group (OR = 1.93–2.7, p < 0.004, 95% CI; 1.24–4.09). After controlling for age, for all findings but linear striations, the OR for having a specific feature was higher in the study group. Women in the study group with ≥ 5 sonographic signs of adenomyosis had more than twice the risk of experiencing infertility (OR = 2.31, p = 0.012, 95% CI; 1.20–4.45). Sonographic signs of adenomyosis are more prevalent in women with symptomatic endometriosis who underwent surgery compared with those who continued conservative management. Women with 5+ findings have a significantly increased risk of infertility. Adenomyosis on ultrasound should be considered in the management decisions regarding these patients.

Characterization of the Endometrial MSC Marker Ectonucleoside Triphosphate Diphosphohydrolase-2 (NTPDase2/CD39L1) in Low- and High-Grade Endometrial Carcinomas: Loss of Stromal Expression in the Invasive Phenotypes

Ectonucleoside triphosphate diphosphohydrolase-2 (NTPDase2/CD39L1) has been described in human non-pathological endometrium in both epithelial and stromal components without changes along the cycle. It was identified as a stromal marker of basalis. In the present study, we aimed to evaluate NTPDase2 distribution, using immunolabeling and in situ enzyme activity approaches, in endometrial carcinoma (EC) at different tumor grades. NTPDase2 was present in tumor epithelial EC cells, as in the non-pathological endometria, but the expression underwent changes in subcellular distribution and also tended to decrease with the tumor grade. In stroma, NTPDase2 was identified exclusively at the tumor-myometrial junction but this expression was lost in tumors of invasive phenotype. We have also identified in EC samples the presence of the perivascular population of endometrial mesenchymal stem cells (eMSCs) positive for sushi domain containing 2 (SUSD2) and for NTPDase2, already described in non-tumoral endometrium. Our results point to NTPDase2 as a histopathological marker of tumor invasion in EC, with diagnostic relevance especially in cases of EC coexisting with other endometrial disorders, such as adenomyosis, which occasionally hampers the assessment of tumor invasion parameters.

Junctional zone endometrium alterations in gynecological and obstetrical disorders and impact on diagnosis, prognosis and treatment

PURPOSE OF REVIEW

To investigate the JZE alterations in gynecological and obstetrical disorders and impact on diagnosis, prognosis and treatment.

RECENT FINDINGS

JZE was found to be significantly extended in patients with endometriosis, leading to the conclusion that endometriosis is a primary disease of the uterus, much like adenomyosis. Statistical correlation was then demonstrated between the severity of endometriosis and the depth of the adenomyosis infiltrates, hence the thickening of the JZE. Stem cells, predominantly found in the JZE were also found in histological sections of leiomyoma, suggested to be the origin of leiomyoma. This reservoir of JZE stem cells is influenced by different stressors leading to their differentiation into leiomyoma, endometriosis, adenomyosis or endometrial cancer, according to the stressor. The variability in presentation was hypothesized to be connected to genetic and epigenetic factors. JZE was also suggested to act as a barrier, stopping endometrial carcinoma cells invasion and metastasis. In addition, JZE plays a major role in conception, pregnancy and postpartum.

SUMMARY

JZE is an important anatomical landmark of the uterus contributing to normal uterine function under the influence of ovarian hormones. Alterations of the JZE thickness and contractility can be used as pathognomonic clinical markers in infertility and chronic pelvic pain, for subendometrial and myometrial disorders, for example, adenomyosis and fibroids. Prospective randomized control trials will clarify the diagnostic steps, imaging modalities to follow and probably triage the patients between medical and surgical treatments.

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.

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.

The effect of transcervical endometrial resection on clinical symptoms related to intrinsic adenomyosis and junctional zone changes

Objectives

To assess the effect of transcervical endometrial resection on clinical symptoms related to histopathological findings of the junctional zone.

Study design

This prospective study took place at a university hospital. Premenopausal women suffering from abnormal uterine bleeding and/or pelvic pain and scheduled for transcervical endometrial resection were enrolled (n = 112). Histopathological findings of the endomyometrial biopsies were categorized as follows: Adenomyosis of the inner myometrium (intrinsic adenomyosis): ≥ 2 mm myometrial invasion without contact to the basal endometrium, serrated junctional zone: > 3 mm myometrial invasion with contact to the basal endometrium and linear junctional zone: No or marginal myometrial invasion (≤ 3 mm) with contact to the basal endometrium. All study participants received a baseline and two follow-up questionnaires (6 and 18 months after surgery) regarding symptom severity, health-related quality of life and pelvic pain. Data regarding reintervention surgery was obtained from the National Database Patoweb. The rate of reintervention surgery and the improvement in symptom severity, health-related quality of life and pelvic pain were correlated to histopathological findings.

Results

Twenty-four patients had intrinsic adenomyosis, 31 had serrated junctional zone and 57 had linear junctional zone. Fifteen patients (13%) underwent reintervention surgery; three (20%) within 6 months, nine (60%) between 6–18 months and three (20%) > 18 months after transcervical endometrial resection. Reintervention surgery was more common in women with intrinsic adenomyosis compared to women without (33% (95% CI: 16–55) vs 8% (95% CI: 3–16)) (p-value: < .05). Nine patients (38%) with intrinsic adenomyosis were asymptomatic based on low symptom severity score, high health-related quality of life and no pelvic pain at 18 months follow-up. Patients with linear junctional zone had a higher improvement in symptom severity and health-related quality of life than patients with intrinsic adenomyosis or serrated junctional zone at 6 months follow-up after surgery (p-value < .05). However, there was no significant difference in pelvic pain reduction.

Conclusion

The effect of transcervical endometrial resection may depend upon the degree of junctional zone changes, and patients with intrinsic adenomyosis are more likely to undergo reintervention surgery than patients with either linear or serrated junctional zone. However, intrinsic adenomyosis may also be successfully treated with endometrial resection.