Morphological changes in hysterectomies after endometrial ablation

Unraveling the Dynamics of Estrogen and Progesterone Signaling in the Endometrium: An Overview

The endometrium is crucial for the perpetuation of human species. It is a complex and dynamic tissue lining the inner wall of the uterus, regulated throughout a woman's life based on estrogen and progesterone fluctuations. During each menstrual cycle, this multicellular tissue undergoes cyclical changes, including regeneration, differentiation in order to allow egg implantation and embryo development, or shedding of the functional layer in the absence of pregnancy. The biology of the endometrium relies on paracrine interactions between epithelial and stromal cells involving complex signaling pathways that are modulated by the variations of estrogen and progesterone levels across the menstrual cycle. Understanding the complexity of estrogen and progesterone receptor signaling will help elucidate the mechanisms underlying normal reproductive physiology and provide fundamental knowledge contributing to a better understanding of the consequences of hormonal imbalances on gynecological conditions and tumorigenesis. In this narrative review, we delve into the physiology of the endometrium, encompassing the complex signaling pathways of estrogen and progesterone.

Regenerative Medicine in Gynecology

The female reproductive tract undergoes dynamic changes across the life span. Congenital abnormalities, life events, and medical interventions can negatively affect the structure and function of reproductive tract organs, resulting in lifelong sequelae. The objective of regenerative gynecology is to discover and promote endogenous mechanisms by which a healthy tissue maintains overall tissue integrity after injury, after disease, or with age. In this review, we discuss some of the key state-of-the-art cell-based and scaffolding therapies that have been applied to regenerate gynecologic tissues and organs primarily in animal and tissue culture models. We further discuss the limitations of current technologies, problems of implementation and scalability, and future outlook of the field.

Mechanisms of Regeneration and Fibrosis in the Endometrium

The uterine lining (endometrium) regenerates repeatedly over the life span as part of its normal physiology. Substantial portions of the endometrium are shed during childbirth (parturition) and, in some species, menstruation, but the tissue is rapidly rebuilt without scarring, rendering it a powerful model of regeneration in mammals. Nonetheless, following some assaults, including medical procedures and infections, the endometrium fails to regenerate and instead forms scars that may interfere with normal endometrial function and contribute to infertility. Thus, the endometrium provides an exceptional platform to answer a central question of regenerative medicine: Why do some systems regenerate while others scar? Here, we review our current understanding of diverse endometrial disruption events in humans, nonhuman primates, and rodents, and the associated mechanisms of regenerative success and failure. Elucidating the determinants of these disparate repair processes promises insights into fundamental mechanisms of mammalian regeneration with substantial implications for reproductive health.

Diagnosis and Treatment of Adenomyosis with Office Hysteroscopy-A Narrative Review of Literature

INTRODUCTION

Adenomyosis is a common chronic disease in women of reproductive age, characterised by the presence of ectopic endometrial tissue within myometrium. Even though adenomyosis presents with chronic pelvic pain, menorrhagia or abnormal uterine bleeding, dysmenorrhoea, and dyspareunia and is often recognised after hysterectomies. However, the development of ultrasonography and magnetic resonance imaging has improved the pre-operative diagnosis of the disease. Hysteroscopy provides information in real time from the uterine cavity and the offers the possibility of obtaining direct biopsies.

MATERIAL AND METHODS

The literature was searched via Pubmed and Embase with the following headings: diagnosis of adenomyosis or adenomyoma and office hysteroscopy, hysteroscopy findings of adenomyosis or adenomyoma, treatment of adenomyosis or adenomyoma with office hysteroscopy.

RESULTS

The literature showed that hysteroscopy can identify superficial adenomyosis. There are a variety of hysteroscopic images that can be connected with the disease. New equipment like the spirotome has been used to access deeper layers of myometrium and obtain biopsies under direct vision from the adenomyotic areas. Different methods of treatment have been also described, like enucleation of focal superficial adenomyoma, coagulation, evacuation of cystic adenomyosis when the lesion is smaller than 1.5 cm, and resection of adenomyotic nodules in case of bigger lesions (>1.5 cm). Diffuse superficial adenomyosis is also managed by resection.

CONCLUSIONS

Hysteroscopy has revolutionised the approach to adenomyosis. It is a useful tool in assessing mainly superficial adenomyosis. The role of hysteroscopy in surgical management of adenomyosis need to be confirmed with further studies.

The Role of Endometrial Stem/Progenitor Cells in Recurrent Reproductive Failure

Recurrent implantation failure (RIF) and recurrent pregnancy loss (RPL), collectively referred to as recurrent reproductive failure (RRF), are both challenging conditions with many unanswered questions relating to causes and management options. Both conditions are proposed to be related to an aberrant endometrial microenvironment, with different proposed aetiologies related to a restrictive or permissive endometrium for an invading embryo. The impressive regenerative capacity of the human endometrium has been well-established and has led to the isolation and characterisation of several subtypes of endometrial stem/progenitor cells (eSPCs). eSPCs are known to be involved in the pathogenesis of endometrium-related disorders (such as endometriosis) and have been proposed to be implicated in the pathogenesis of RRF. This review appraises the current knowledge of eSPCs, and their involvement in RRF, highlighting the considerable unknown aspects in this field, and providing avenues for future research to facilitate much-needed advances in the diagnosis and management of millions of women suffering with RRF.

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

BACKGROUND

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

OBJECTIVE AND RATIONALE

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

SEARCH METHODS

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

OUTCOMES

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

WIDER IMPLICATIONS

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

Isolated Eosinophilic Myometritis: A Case Report of an Extremely Rare Phenomenon

Increased number of eosinophils in the uterus has been reported under physiological and pathologic conditions. However, eosinophilic infiltration limited to the myometrium is very unusual. A rare finding of isolated eosinophilic infiltration in the myometrium without involvement of endometrium or pathologies in the cervix or ovaries was observed in a 31-yr-old woman seeking medical attention for unexplained infertility, abnormal uterine bleeding, and dysmenorrhea. The patient had no allergies, parasitic disease, or other systemic disorders. This rare manifestation of eosinophilic infiltration expands the differential diagnosis of inflammatory conditions of the myometrium in patients with gynecological issues.

Current and Future Surgical and Interventional Management Options for Adenomyosis

Historically, hysterectomy has been the recommended treatment for patients with adenomyosis. However, in the past two decades, various uterine-sparing treatment methods have emerged. These range from excisional techniques such as adenomyomectomy or wedge resection to uterine artery embolization, radiofrequency thermal ablation, hysteroscopic excision, endometrial ablation, and high-intensity focused ultrasound. While largely investigative for the treatment of adenomyosis, these procedures have demonstrated improvement in symptoms including abnormal uterine bleeding, dysmenorrhea, pelvic pain, and overall quality of life. However, long-term data including fertility and obstetric outcomes are needed. Future research is needed to better understand the impact of these uterine-preserving techniques to expand our armamentarium for the treatment of adenomyosis.

Histological 3D reconstruction and in vivo lineage tracing of the human endometrium

Regular menstrual shedding and repair of the endometrial functionalis is unique to humans and higher-order primates. The current consensus postulates endometrial glands to have a single-tubular architecture, where multi-potential stem cells reside in the blind-ending glandular-bases. Utilising fixed samples from patients, we have studied the three-dimensional (3D) micro-architecture of the human endometrium. We demonstrate that some non-branching, single, vertical functionalis glands originate from a complex horizontally interconnecting network of basalis glands. The existence of a multipotent endometrial epithelial stem cell capable of regenerating the entire complement of glandular lineages was demonstrated by in vivo lineage tracing, using naturally occurring somatic mitochondrial DNA mutations as clonal markers. Vertical tracking of mutated clones showed that at least one stem-cell population resides in the basalis glands. These novel findings provide insight into the efficient and scar-less regenerative potential of the human endometrium. © 2020 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Histologic findings in hysterectomies after endometrial ablation

BACKGROUND

Endometrial ablation for abnormal uterine bleeding is used as a less invasive alternative to hysterectomy, however, in cases of treatment failure hysterectomy may be finally performed. The histologic changes in these post-treatment uteri are not well-described.

OBJECTIVE

To describe the histological findings in post-endometrial ablation uteri.

STUDY DESIGN

During a ten-year period, 321 patients were treated with endometrial ablation. Twenty-five patients (7.8%), 10 treated with NovaSure® and 15 treated with ThermaChoice® endometrial ablation were finally subjected to hysterectomy mostly due to persistent uterine bleeding. Histologic features of these hysterectomies are described.

RESULTS

The patients' age ranged from 33 to 73 years (mean 44.5) and 34-53 (mean 42) for the NovaSure® and ThermaChoice® group, respectively. The time from endometrial ablation to hysterectomy was 2-24 months (mean 8.8) and 2-60 months (mean 23.2) for the two groups, respectively (p = 0.01). Hysterectomies performed later (mean 22 months) showed no fibrosis (p = 0.04) compared with those performed earlier (mean 5 months). Endometrial lining was found more frequently in hysterectomies performed later (mean 13 months) than those performed earlier (mean 2 months, p = 0.0004). Abundant necrotic tissue of myometrial origin was found in 28% of the cases, but it was not associated with the time of hysterectomy (p = 0.2). A zonation effect and vascular changes also seen. Granulomatous reaction was not found. Ten patients (40%) harbored adenomyosis and another three (12%) extensive leiomyomas/diffuse leiomyomatosis.

CONCLUSION

Necrosis, fibrosis and vascular changes are found during the first year of post-thermal uterine effect. Hysterectomies performed later show less prominent changes and almost normal endometrial lining. Adenomyosis is found in an important part of post-endometrial ablation hysterectomies.

Clinical and histopathologic characteristics of patients undergoing surgical excision with Essure coils: Longitudinal experience at a women's specialty hospital

The introduction of the Essure (Bayer AG, Leverkusen, Germany) device made possible a less invasive approach for patients desiring sterilization. Following FDA approval in 2002, problems were reported in some patients with these devices including most commonly pain. Labeling changes were mandated in 2016, and as of late 2018, the devices are no longer being sold in the United States. A comprehensive description of Pathologic findings in patients with these devices has not been reported. This study characterizes pathologic findings in patients undergoing surgery who had Essure in place, regardless of the indication for surgery. 137 cases were found, 126 of which had submitted tissue, 121 of which had fallopian tube(s) submitted. Duration for coils being in place was available for 104/137 patients (mean 48 months; median 43 months, range 0-166 months). Cases ranged from 2009 to 19, with a peak in cases noted in 2016. A chief complaint relating to the phrase "pelvic pain" was the most common, noted in 72/137 cases. Obliteration, defined as loss of the fallopian tube epithelium with filling of the lumen with fibrotic material, was noted in 33/121 cases. Inflammation was noted in 59/126 cases, 31/59 showed with giant cells, chronic inflammation (lymphocytes and/or plasma cells) in 37/59 cases, and acute inflammation 19/59 cases, with 14/19 showing eosinophils. Acute inflammation was noted in those with a shorter duration of coil implantation, while chronic inflammation, including giant cells, were noted across the span. This study has expanded knowledge of patients with removal of Essure coil devices.

Endometrial Stem Cell Markers: Current Concepts and Unresolved Questions

The human endometrium is a highly regenerative organ undergoing over 400 cycles of shedding and regeneration over a woman’s lifetime. Menstrual shedding and the subsequent repair of the functional layer of the endometrium is a process unique to humans and higher-order primates. This massive regenerative capacity is thought to have a stem cell basis, with human endometrial stromal stem cells having already been extensively studied. Studies on endometrial epithelial stem cells are sparse, and the current belief is that the endometrial epithelial stem cells reside in the terminal ends of the basalis glands at the endometrial/myometrial interface. Since almost all endometrial pathologies are thought to originate from aberrations in stem cells that regularly regenerate the functionalis layer, expansion of our current understanding of stem cells is necessary in order for curative treatment strategies to be developed. This review critically appraises the postulated markers in order to identify endometrial stem cells. It also examines the current evidence supporting the existence of epithelial stem cells in the human endometrium that are likely to be involved both in glandular regeneration and in the pathogenesis of endometrial proliferative diseases such as endometriosis and endometrial cancer.

Endometrial ablation: normal appearance and complications

Global endometrial ablation is a commonly performed, minimally invasive technique aimed at improving/resolving abnormal uterine bleeding and menorrhagia in women. As non-resectoscopic techniques have come into existence, endometrial ablation performance continues to increase due to accessibility and decreased requirements for operating room time and advanced technical training. The increased utilization of this method translates into increased imaging of patients who have undergone the procedure. An understanding of the expected imaging appearances of endometrial ablation using different modalities is important for the abdominal radiologist. In addition, the frequent usage of the technique naturally comes with complications requiring appropriate imaging work-up. We review the expected appearance of the post-endometrial ablated uterus on multiple imaging modalities and demonstrate the more common and rare complications seen in the immediate post-procedural time period and remotely.

Endometrial ablation

Endometrial ablation (EA) includes a spectrum of procedures performed with or without hysteroscopic direction, designed to destroy the endometrium for the treatment of the symptom of heavy menstrual bleeding (HMB) secondary to a spectrum of causes, but most commonly those that are endometrial in origin (AUB-E) or ovulatory disorders (AUB-O). Resectoscopic endometrial ablation (REA) is often mistakenly referred to as the "first generation" technique, while proprietary devices that do not use the resectoscope (nonresectoscopic EA or NREA) are often misperceived as "second generation" devices. Indeed, the origins of NREA date back to the late 19th century with the use of steam, and the early and mid 20th century, when radiofrequency and cryotherapy based NREA techniques were published - long before the resectoscope was used and reported. The NREA devices have also been mislabeled as "global", a misleading term borrowed from the marketing departments of device manufacturers - there is no device that predictably treats the entire endometrium. Consequently, none can be construed as being "global". Instead, EA is a procedure designed for women as an alternative to hysterectomy, or, perhaps, medical therapy, when future fertility is no longer desired. Women who select EA should anticipate a relatively low risk procedure that will likely reduce their HMB to normal levels or less. This paper will review the spectrum of EA techniques and devices, their clinical outcomes and adverse events, and explore their value compared to hysterectomy and selected medical therapies.

Late-onset endometrial ablation failure

Endometrial ablation, first reported in the 19th century, has gained wide acceptance in the gynecologic community as an important tool for the management of abnormal uterine bleeding when medical management has been unsuccessful or contraindicated. The introduction of global endometrial ablation (GEA) devices beginning in 1997 has provided unsurpassed safety addressing many of the concerns associated with their resectoscopic predecessors. As of this writing the GEA market has surpassed a half-million devices in the United States per annum and has an expected compound annual growth rate (CAGR) projected to be 5.5% from 2016 to 2024.

While the short term safety and efficacy of these devices has been reported in numerous clinical trials we only recently are becoming aware of the high incidence of late-onset endometrial ablation failures (LOEAFs) associated with these procedures. Currently, about a quarter of women who undergo a GEA procedure will eventually require a hysterectomy while an unknown number have less than satisfactory results. In order to reduce these suboptimal outcomes physicians must better understand the etiology and risk factors that predispose a patient toward the development of LOEAF as well as current knowledge of patient and procedure selection for EA as well as treatment options for these delayed complications.

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Over 500,000 endometrial ablations (EAs) are performed in the U. S. each year.

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Late-onset endometrial ablation failures (LOEAFs) are the most common complication of EA.

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25% of women who undergo EA will require hysterectomy within 5 years.

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Reducing the incidence of LOEAFs requires improved patient selection for EA.

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Ultrasound-guided reoperative hysteroscopic surgery (UGRHS) reduces the need hysterectomy following LOEAF.

Sonographic findings in postmenopausal women with a prior endometrial ablation: interpretation and management of women with endometrial thickening and bleeding

OBJECTIVE

To understand the meaning of endometrial thickening and bleeding in postmenopausal women who had previously undergone endometrial ablation (EA).

DESIGN

Retrospective observational study. Canadian Task Force III.

SETTING

Obstetrics and Gynecology Unit, Magna Graecia University, Catanzaro, Italy.

PATIENTS

Sixty-three postmenopausal women who had previously undergone EA.

INTERVENTIONS

A retrospective evaluation of clinical charts of postmenopausal women who had a follow-up visit after EA between January 2000 and August 2014.

MEASUREMENTS AND MAIN RESULTS

The rates of endometrial thickening (with or without bleeding), endometrial atrophy, and cancer were determined. Postmenopausal bleeding was reported in 9 patients (14.3%). Endometrial thickening was observed in 51 patients (80.9%; mean ± SD endometrial thickness, 7.7 ± 3.0 mm). A significantly (p < .05) greater number of patients with an endometrial thickness of 5 to 10 mm was observed compared with those with an endometrial thickness of <5 mm or >10 mm. A significant (p = .001) difference in increase in endometrial thickness was observed between patients with and without bleeding. Overall, hysteroscopy plus endometrial biopsy was scheduled in 24 patients. In all bleeding women, a histological diagnosis of endometrial atrophy was demonstrated. Concerning bleeding-free women, in 14 patients with endometrial thickening of >10 mm, mucosal atrophy was detected. The only bleeding-free patient in whom an endometrial echogenic fluid collection was detected had a histological diagnosis of endometrioid endometrial cancer. Thus, patients who underwent hysteroscopy had a 95.8% rate of mucosal atrophy and a 4.2% rate of endometrial cancer. The overall cancer rate in our global population (menopause with previous EA) was 1.6%.

CONCLUSION

Postmenopausal bleeding and sonographic detection of endometrial thickening in patients with previous EA are not necessarily related to a malignant disease. Nonetheless, ultrasound visualization of endometrial thickening plus an echogenic endometrial fluid collection in these patients always warrants an invasive diagnostic procedure regardless of whether or not bleeding is reported.

Characteristics of patients undergoing hysterectomy for failed endometrial ablation

BACKGROUND AND OBJECTIVES

Endometrial ablation is a minimally invasive procedure for menorrhagia. High success rates are documented with >90% of patients experiencing satisfaction. However, adequate relief after endometrial ablation is not obtained in a cohort of patients. The purpose of this study is to identify the characteristics of patients for whom endometrial ablation fails due to persistent symptoms, causing them to choose hysterectomy for definitive treatment.

METHODS

We conducted a retrospective chart review of patients who underwent hysterectomy for persistent menorrhagia, pain, or both, who previously had endometrial ablation. We reviewed medical records including pathology reports from hysterectomy. We compared demographics to a group previously studied at our institution that were identified as satisfied 5 years after ablation.

RESULTS

The number of patients in our study group was 51 (n = 51). Median age of patients was 39 (range 29-50) years. Average body mass index was 31 (range 19-47) kg/m(2). Average parity was 1.9. Sixty-nine percent underwent tubal ligation. The majority were nonsmokers (75%). Ninety-six percent were Caucasian. Compared with the previously studied satisfied group, the only statistically significant difference was age. Of 51 patients, 11 (22%) noted pelvic pain as their chief concern. Menorrhagia was the chief concern in 22 (43%). Eighteen patients (35%) complained of both. The most common diagnosis was endometriosis, which was identified in 35 patients (68%). Leiomyomata were present in 33 patients (64%). Adenomyosis was identified in 22 patients (43%).

CONCLUSIONS

Patients who present for hysterectomy after endometrial ablation have a high rate of endometriosis, adenomyosis, and leiomyomata, with endometriosis being the most common finding.

Giant cell tumor of uterus resembling osseous giant cell tumor: case report and review of literature

Osteoclast-like giant cells (OLGCs) are multinucleated cells of histiocytic lineage and have been identified in a wide array of neoplasms. In the uterus, they have most frequently been reported in association with leiomyosarcomas. This article describes a case of an osteoclast-like giant cell-rich uterine tumor that was essentially indistinguishable at the morphologic and immunophenotypic levels, from typical giant cell tumor of bone. This is the first example of such a case that has been reported in the uterus to the authors' knowledge.

Endometrial stem cells and reproduction

Abnormal endometrial function remains a significant cause of implantation failure, recurrent pregnancy loss, and other pathologies responsible for female infertility. The development of novel therapies to treat infertility due to endometrial dysfunction requires an understanding of the latest advancements in endometrial cell biology, such as the role of endometrial stem cells. The remarkable regenerative capacity of the human endometrium is absolutely essential for successful reproduction and likely requires a population of stem cells in the endometrium. The purpose of this review is to provide an introduction to some of the newest concepts in endometrial stem cell biology.

Menstrual activity of matrix metalloproteinases is decreased in endometrium regenerating after thermal ablation

BACKGROUND

Menstruation is associated with a striking increase in matrix metalloproteinase (MMP) activity. However, it is still unknown whether the level of MMP activity correlates with the amount of menstrual bleeding.

METHODS

We used histochemistry to investigate the degradation of the extracellular matrix (ECM), and immunohistochemical labelling and zymographic analysis to determine the level of expression and activity of MMP-2 and -9, and of their tissue inhibitors (TIMPs) -1, -2 and -3, in endometria sampled during menstruation in 14 women experiencing excessive menstrual bleeding and in 10 women successfully treated for menorrhagia by thermal ablation of the endometrium.

RESULTS

After thermal ablation, regenerated menstrual endometria showed reduced areas of collagen fibre lysis and increased content of TIMP-1 and TIMP-2 compared with endometria from non-treated menorrhagic women. Surprisingly, treated endometria contained more latent gelatinase A (proMMP-2) but a lower proportion of the active form of gelatinase B (MMP-9) than non-treated endometria.

CONCLUSIONS

These results suggest that ECM degradation is decreased at menstruation in the endometrium regenerated after thermal ablation, mostly because of an increased TIMP expression. This represents the first molecular explanation for the decreased amount of menstrual bleeding.

Management of Heavy Menstrual Bleeding: Is Hysterectomy the Radical Mastectomy of Gynecology?

Both hysterectomy for heavy menstrual bleeding and radical mastectomy for breast cancer are steeped in the history of surgery and have recently been challenged as being too radical for the disorder at hand. Radical mastectomy has largely been replaced with local removal of the tumor with subsequent radiation and/or chemotherapy. Alternatives to hysterectomy include a number of medical interventions, most notably intrauterine progestin-releasing systems, and endometrial ablation, a procedure that has a relatively high success rate and one that is now feasible for many women in an office or procedure room setting. However, although radical mastectomy rates have dropped precipitously, hysterectomy rates, at least in the United States remain relatively stable. Determining the proportion of hysterectomies that are done for heavy menstrual bleeding is difficult, largely because of coding issues, so it is difficult to measure the impact of new medical and minimally invasive surgical procedures. Nevertheless, it seems clear that many women are not exposed to the plethora of options to hysterectomy, a fact that may reflect a number of issues that may include training, skill, and financial incentives or disincentives. Clearly, options to hysterectomy are not a panacea, but if women are empowered to select from all of the options available, the rate of hysterectomy for bleeding should decrease while maintaining, or even enhancing the patient's satisfaction with care.

Uterine stem cells: what is the evidence?

The mucosal lining (endometrium) of the human uterus undergoes cyclical processes of regeneration, differentiation and shedding as part of the menstrual cycle. Endometrial regeneration also follows parturition, almost complete resection and in post-menopausal women taking estrogen replacement therapy. In non-menstruating species, there are cycles of endometrial growth and apoptosis rather than physical shedding. The concept that endometrial stem/progenitor cells are responsible for the remarkable regenerative capacity of endometrium was proposed many years ago. However, attempts to isolate, characterize and locate endometrial stem cells have only been undertaken in the last few years as experimental approaches to identify adult stem/progenitor cells in other tissues have been developed. Adult stem cells are defined by their functional properties rather than by marker expression. Evidence for the existence of adult stem/progenitor cells in human and mouse endometrium is now emerging because functional stem cell assays are being applied to uterine cells and tissues. These fundamental studies on endometrial stem/progenitor cells will provide new insights into the pathophysiology of various gynaecological disorders associated with abnormal endometrial proliferation, including endometrial cancer, endometrial hyperplasia, endometriosis and adenomyosis.

Idiopathic Uterine Granulomas

Granulomas in the uterine corpus and cervix are rare, with most examples obviously a result of a previous operative or ablative procedure. In this report, we describe 8 cases where granulomas, not associated with a previous procedure, were identified as an incidental finding in the myometrium or cervical stroma. A review of the clinical records revealed no obvious cause for the granulomatous inflammation, and we propose the term "idiopathic uterine granulomas." In all cases, the granulomas, which in most cases were multiple, were well circumscribed and intimately related to thin-walled vascular channels that showed no evidence of vasculitis. This resulted in a characteristic histological appearance similar to that seen with so-called "idiopathic ovarian cortical granulomas." Although local and systemic causes of granulomatous inflammation should be excluded, granulomas in the myometrium and cervical stroma may occur without an obvious underlying cause.

Insertion of Mirena after Endometrial Resection in Patients with Adenomyosis

STUDY OBJECTIVE

To evaluate the efficacy of Mirena, a levonorgestrel-releasing intrauterine device, after endometrial resection for treatment of menorrhagia caused by adenomyosis.

DESIGN

Open, randomized, observational study (Canadian Task Force classification II-2).

SETTING

Private hospital.

PATIENTS

Ninety-five women.

INTERVENTION

Endometrial resection, after which control patients received no further treatment and study patients had Mirena inserted immediately after the procedure.

MEASUREMENTS AND MAIN RESULTS

The rate of amenorrhea after 1 year was significantly higher in the Mirena group. Nineteen percent of women in the control group had a second procedure to control bleeding compared with none in the Mirena group.

CONCLUSION

Insertion of Mirena after endometrial resection is effective treatment for menorrhagia caused by adenomyosis and has very few adverse effects.

Uterine leiomyomas with Eosinophils: a clinicopathologic study of 3 cases

Although leiomyomas (LMs) of the uterus are common, hematopoietic components within these tumors are not. Lymphoid and other hematopoietic elements have been previously recognized, but eosinophilic infiltrates in LMs have received little attention in the literature. The clinical and pathologic features of 3 cases of uterine LM with eosinophilic infiltration were studied. The patients ranged in age from 35 to 62 years and presented with abdominal and/or pelvic pain and abnormal uterine bleeding. None had peripheral blood eosinophilia or clinical evidence of allergy or parasitic infection. One patient had a benign LM, and the other 2 patients had smooth muscle tumors of uncertain malignant potential. The tumors contained variable numbers of eosinophils and Giemsa stains showed variable numbers of mast cells in addition to the eosinophils. We also performed immunohistochemical and in situ hybridization studies to assess for interleukin-5 (IL-5) and eotaxin in these LMs. There was no consistent association between the presence of eosinophils and either IL-5 or eotaxin in smooth muscle cells, suggesting that mechanisms other than IL-5 or eotaxin production may account for the eosinophilia. Because eosinophils are believed to be involved in wound healing, tissue remodeling, and fibrosis, their presence within LMs may reflect a response to tissue injury produced by the neoplasm rather than intrinsic recruitment by chemotactic factors produced by the smooth muscle cells. Their presence, however, does not appear to have any clinical significance.