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.

Placental bed research: I. The placental bed: from spiral arteries remodeling to the great obstetrical syndromes.

The term placental bed was coined to describe the maternal-fetal interface (ie, the area in which the placenta attaches itself to the uterus). Appropriate vascularization of this area is of vital importance for the development of the fetus; this is why systematic investigations of this area have now been carried out. Initially, the challenge was the identification and classification of the various successive branching of uterine arteries in this area. These vessels have a unique importance because failure of their physiological transformation is considered to be the anatomical basis for reduced perfusion to the intervillous space in women with preeclampsia, fetal growth restriction, preterm labor, preterm premature rupture of membranes, abruptio placentae, and fetal death. To investigate in depth the pathophysiology of the placental bed, some 60 years ago, a large number of placental bed biopsies, as well as of cesarean hysterectomy specimens with placenta in situ, from both early and late normotensive and hypertensive pregnancies, were carefully dissected and analyzed. Thanks to the presence of a series of specific physiological changes, characterized by the invasion and substitution of the arterial intima by trophoblast, this material allowed the identification in the placental bed of normal pregnancies of the main vessels, the uteroplacental arteries. It was then discovered that preeclampsia is associated with defective or absent transformation of the myometrial segment of the uteroplacental arteries. In addition, in severe hypertensive disease, atherosclerotic lesions were also found in the defective myometrial segment. Finally, in the basal decidua, a unique vascular lesion, coined acute atherosis, was also identified This disorder of deep placentation, coined defective deep placentation, has been associated with the great obstetrical syndromes, grouping together preeclampsia, intrauterine growth restriction, preterm labor, preterm premature rupture of membranes, late spontaneous abortion, and abruptio placentae. More recently, simplified techniques of tissue sampling have been also introduced: decidual suction allows to obtain a large number of decidual arteries, although their origin in the placental bed cannot be determined. Biopsies parallel to the surface of the basal plate have been more interesting, making possible to identify the vessels' region (central, paracentral, or peripheral) of origin in the placental bed and providing decidual material for immunohistochemical studies. Finally, histochemical and electron microscopy investigations have now clarified the pathology and pathogenetic mechanisms underlying the impairment of the physiological vascular changes.

Preeclampsia: the role of persistent endothelial cells in uteroplacental arteries.

We explore the potential role of the endothelial lining of uteroplacental arteries in the pathogenesis of preeclampsia, a severe pregnancy disorder characterized by incomplete invasion of the uterine vasculature by extravillous trophoblast and angiogenic imbalance. In normal pregnancy, the endothelium disappears progressively from the uteroplacental arteries and is replaced by trophoblast and deposition of fibrofibrinoid structure, underpinning the so-called physiological transformation of uterine spiral arteries. We hypothesize that partial persistence of the endothelium, albeit injured, initiates a chain of events leading to the emergence of preeclampsia in 3 sequential stages. The first stage results in retention of the endothelium in uteroplacental arteries secondary to incomplete physiological transformation of the vessels. Consequently, the uteroplacental vessels are reactive to pathological cues, which drives local arteriopathy. The second stage starts with progressive reduction in uteroplacental blood flow, generating oxidative stress in the whole placenta, and heightened maternal inflammation in response to circulating trophoblastic debris. In the third stage, generalized endotheliosis causes systemic angiogenic imbalance, hypertension, and other clinical manifestation of preeclampsia.

Placental bed research: II. Functional and immunological investigations of the placental bed.

Research on the placenta as the interface between the mother and the fetus has been undertaken for some 150 years, and in 2 subsequent reviews, we attempted to summarize the situation. In the first part, we described the discovery of unique physiological modifications of the uteroplacental spiral arteries, enabling them to cope with a major increase in blood flow necessary to ensure proper growth of the fetus. These consist of an invasion of the arterial walls by trophoblast and a progressive disappearance of its normal structure. Researchers then turned to the pathophysiology of the placental bed and in particular to its maternal vascular tree. This yielded vital information for a better understanding of the so-called great obstetrical syndromes (preeclampsia, fetal growth restriction, premature labor and delivery, placenta accreta). Systematic morphological investigations of the uteroplacental vasculature showed that preeclampsia is associated with decreased or failed transformation of spiral arteries and the persistence of endothelial and smooth muscle cells in segments of their myometrial portion. Here we report on recent functional investigations of the placental bed, including in situ biophysical studies of uteroplacental blood flow and vascular resistance, and manipulation of uteroplacental perfusion. These new methodologies have provided a novel way of identifying pregnancies in which remodeling is impaired. In animals it is now possible to manipulate uteroplacental blood flow, leading to an enhancement of fetal growth; this opens the way to trials in abnormal human pregnancies. In this second part, we explored a new, extremely important area of research that deals with the role of specific subsets of leukocytes and macrophages in the placental bed. The human first-trimester decidua is rich in leukocytes called uterine natural killer cells. Both macrophages and uterine natural killer cells increase in number from the secretory endometrium to early pregnancy and play a critical role in mediating the process of spiral artery transformation by inducing initial structural changes. It seems therefore that vascular remodeling of spiral arteries is initiated independently of trophoblast invasion. Dysregulation of the immune system may lead to reproductive failure or pregnancy complications, and in this respect, recent studies have advanced our understanding of the mechanisms regulating immunological tolerance during pregnancy, with several mechanisms being proposed for the development of tolerance to the semiallogeneic fetus. In particular, these include several strategies by which the trophoblast avoids maternal recognition. Finally, an important new dimension is being explored: the likelihood that pregnancy syndromes and impaired uteroplacental vascular remodeling may be linked to future maternal and even the child's cardiovascular disease risk. The functional evidence underlying these observations will be discussed.

Uncommon Mixed Endometrial-Myometrial Benign Tumors of the Reproductive Tract: Literature Review.

BACKGROUND: We reviewed published cases of uterus-like mass (U-LM), endomyometriosis, polypoid adenomyoma (PA), adenomyomatous polyp, atypical PA (APA), and adenomyoma. SEARCH METHODS: PubMed, Medline, and Scopus searches of all cases published in the databases till November 26, 2018. RESULTS: We identified 45 case reports of U-LM in the pelvis, 10 cases of endomyometriosis, 44 cases of adenomyomatous polyp, 466 cases of APA and case series of adenomyoma and PA. Most case reports focused on histological description of removed lesions with no or very limited clinical correlates. Histological descriptions were often used interchangeably, which creates considerable confusion. It is unclear if endomyometriosis warrants inclusions as a distinct entity, since the distinction is blurred between adenomyomatous polyp and PA. The glandular epithelium in atypical polypoid adenomyoma exhibits atypia and the lesions have a tendency to recur with a risk of malignant transformation. Smooth muscle metaplasia and Müllerian fusion defects have been proposed as etiology, but it is possible that the lesions do not share a common origin. CONCLUSION: There is need for more detailed and structured description of reported cases including clinical presentation and associated pathology.

Progress in the diagnosis and management of adolescent endometriosis: an opinion.

Increasing evidence indicates that early onset endometriosis (EOE), starting around menarche or early adolescence, may have an origin different from the adult variant, originating from neonatal uterine bleeding (NUB). This implies seeding of naïve endometrial progenitor cells into the pelvic cavity with NUB; these can then activate around thelarche. It has its own pathophysiology, symptomatology and risk factors, warranting critical management re-evaluation. It can also be progressive, endangering future reproductive capacity. This variant seems to be characterized by the presence of ovarian endometrioma. Today, the diagnosis of endometriosis in young patients is often delayed for years; if rapidly progressive, it can severely affect pelvic organs, even in the absence of serious symptoms. Given the predicament, great attention must be paid to symptomatology that is often non-specific, justifying a search for new, simple, non-invasive markers of increased risk. Better use of modern imaging techniques will aid considerably in screening for the presence of EOE. Traditional laparoscopy should be limited to cases in which imaging gives rise to suspicion of severity and a stepwise, minimally invasive approach should be used, followed by medical treatment to prevent recurrence. In conclusion, EOE represents a condition necessitating early diagnosis and stepwise management, including medical treatment.

Adenomyosis and Endometrial Cancer: Literature Review.

To confirm the origin of cancer found in both the endometrium and the myometrium is difficult. Cancer may spread from the endometrium into adenomyotic foci or vice versa. Also, premalignant changes may arise at either or both sites. Investigating disease origin enhances our understanding of pathophysiology and prognosis. Additional critical questions are whether women with adenomyosis have a higher risk of endometrial cancer; whether the invasive properties and prognosis of cancer in adenomyosis differ from those arising in the eutopic endometrium and whether the ectopic glandular tissue in adenomyosis becomes altered in the presence of eutopic endometrial cancer. A final question is whether cancer arising within adenomyosis carries a worse prognosis because of its location within the myometrium and the possibility that the presence of adenomyosis facilitates invasion of cancer arising in the eutopic endometrium. The present review explores currently available literature in an attempt to answer these questions and to examine clinical presentations, diagnostic criteria, pathogenesis and prognosis.

The impact of uterine immaturity on obstetrical syndromes during adolescence.

Pregnant nulliparous adolescents are at increased risk, inversely proportional to their age, of major obstetric syndromes, including preeclampsia, fetal growth restriction, and preterm birth. Emerging evidence indicates that biological immaturity of the uterus accounts for the increased incidence of obstetrical disorders in very young mothers, possibly compounded by sociodemographic factors associated with teenage pregnancy. The endometrium in most newborns is intrinsically resistant to progesterone signaling, and the rate of transition to a fully responsive tissue likely determines pregnancy outcome during adolescence. In addition to ontogenetic progesterone resistance, other factors appear important for the transition of the immature uterus to a functional organ, including estrogen-dependent growth and tissue-specific conditioning of uterine natural killer cells, which plays a critical role in vascular adaptation during pregnancy. The perivascular space around the spiral arteries is rich in endometrial mesenchymal stem-like cells, and dynamic changes in this niche are essential to accommodate endovascular trophoblast invasion and deep placentation. Here we evaluate the intrinsic (uterine-specific) mechanisms that predispose adolescent mothers to the great obstetrical syndromes and discuss the convergence of extrinsic risk factors that may be amenable to intervention.

Promoting awareness of neonatal menstruation.

Neonatal uterine bleeding (NUB) has been carefully studied in the past through case reports, small series, clinical cohort studies, pathology investigations of fetal and neonatal. Following a historical recount, this review summarizes biological mechanisms conditioning NUB, starting from the persistence till birth of an 'ontogenetic progesterone resistance' (OPR), causing decreased responsiveness of target tissues to bioavailable progesterone. Several pregnancy-related conditions, such as preeclampsia, fetal growth restriction, prematurity, post-maturity and even Rhesus or ABO incompatibility, influence the occurrence of NUB. It seems therefore that the phenomenon is precipitated by chronic fetal distress. When present, OPR may persists until telarche; as a consequence, if pregnancy occurs in early teenage, the disorder known as "defective deep placentation" may ensue, increasing the risk of obstetrical syndromes. In the presence of NUB, retrograde shedding into the peritoneal cavity of endometrial stem/progenitor and niche cells may occur. There, given the right environment, these cells can survive and become activated at the time of telarche, causing the specific phenotype of early-onset endometriosis. In conclusion, neonatal menstruation is a fetal distress indicator and can alter the incidence of a variety of pathological conditions later in life. For this reason, it should be carefully recorded and the parents informed.

Decidual Bleeding as a Cause of Spontaneous Hemoperitoneum in Pregnancy and Risk of Preterm Birth.

BACKGROUND: Spontaneous hemoperitoneum in pregnancy (SHiP) is a rare, life-threatening event, particularly relevant to women with endometriosis or deciduosis. METHODS: To determine the type of lesions leading to SHiP, a literature search was conducted among all published SHiP cases. From a total of 1,339 publications, information on pathological findings at the bleeding site with histological data was found in 24 case reports (16 pregnant, 8 postpartum). RESULTS: Among pregnant women (81% primigravida), 75% had a diagnosis of endometriosis and 25% of deciduosis. Among postpartum women (38% primiparous), 63% had a diagnosis of deciduosis and 25% of endometriosis. In all cases except one, decidual cells, with or without glandular structures, were present at the bleeding site. Decidual vessels were described in 7 cases and all exhibited vascular changes, including distension of the lumen, medial disorganization, or loss of vascular integrity. These vessels were significantly different from arteries seen in the secretory endometrium, showing that structural modifications take place during the initial stage of the remodelling of placental bed spiral arteries. CONCLUSIONS: During pregnancy, a link seems to exist between ectopic decidualization, particularly that occurring in endometriotic foci, and occurrence of SHiP. In addition, subclinical decidual bleeding may be a potential risk factor for preterm labour.

A new approach to the management of ovarian endometrioma to prevent tissue damage and recurrence.

Management of ovarian endometrioma is a matter of debate between those advocating early treatment and those believing that cysts less than 3 cm in diameter should not be submitted to surgery. To explore a new approach to its management capable of preserving future fertility, the molecular pathology of ovarian endometrioma is reviewed and mechanisms by which the endometrioma progressively affects the ovary during reproductive life are summarized. The scope of new therapeutic modalities includes restoring the progesterone receptor ratio using progestin or progesterone receptor modulators and decreasing local oestrogen production through an aromatase inhibitor. In addition, free radical production can be blocked by antioxidants and the autophagic process by increasing apoptosis. Finally, metalloproteinases and relaxin activity, as well as the inflammatory process can be controlled. Many of these pharmacological treatments lend themselves to local administration and can be applied through intracystic drug administration; in fact, the intracystic route has already been tried with recombinant interleukin-2, methotrexate and ethanol; the latter to obtain sclerotization. Specifically, it is proposed that endometrial growth in the endometrioma is suppressed by intra-cystic application of synthetic progestins, such as levonorgestrel or danazol, selective progesterone receptor modulators, such as mifepristone, ulipristal or asoprisnil, without affecting ovarian activity.

Adenomyosis: a life-cycle approach.

The life-cycle approach to endometriosis highlighted unexpected features of the condition; the same approach was therefore applied to gain insight into the clinical features of adenomyosis and to draw a comparison with endometriosis. This is possible today thanks to new imaging techniques enabling non-invasive diagnosis of adenomyosis. The specificity and sensitivity of magnetic resonance imaging and transvaginal ultrasound remain uncertain. Unlike endometriosis, little information is available on the presence of classic adenomyosis in adolescents, except for rare cystic forms that may not represent the true disease. Adenomyosis is most likely to affect adult women, although most reported incidences are still based on post-hysterectomy studies, and are affected by diligence in histopathologic diagnosis and the adopted cut-off point. The traditionally accepted associations of adult adenomyosis, such as multiparity, a link to infertility and its effect on pregnancy are uncertain. Active adenomyosis has been found in pre- and peri-menopausal women and in postmenopausal women receiving tamoxifen. In conclusion, major diagnostic limitations and the systematic bias of hysterectomy make it difficult to draw firm conclusions from existing evidence. In addition, no information is available on the natural history of adenomyosis and no study has systematically evaluated its existence in adolescents.

Menstrual preconditioning for the prevention of major obstetrical syndromes in polycystic ovary syndrome.

The presence of multiple ovarian cysts, anovulation, and endometrial progesterone resistance in the neonate seems remarkably similar to ovarian and endometrial features of the polycystic ovary syndrome (PCOS) of adolescent and adult women. In fact, in the absence of cyclic menstruations after menarche, the neonatal progesterone resistance is likely to persist and adversely affect young women with PCOS at the time of pregnancy after induction of ovulation, because any persisting defect in progesterone response can interfere with the process of decidualization and trophoblast invasion. The primigravid woman with PCOS therefore is likely to be at risk of defective deep placentation as manifested by the increased risk of major obstetric syndromes. A recent, large epidemiologic study has demonstrated that the risk of preeclampsia and preterm delivery is elevated in the 13- to 15-year old group, although it does not persist in the 16- to 17-year old group. It is proposed therefore that induction of ovulation in the infertile nulligravid woman with PCOS should be preceded by a period of progesterone withdrawal bleedings to achieve full endometrial progesterone response by the time of pregnancy. The cyclic administration of clomiphene citrate for a period to be determined by vascular response may be an appropriate tool to reduce the risk of major obstetric syndromes by menstrual preconditioning.

The potential perinatal origin of placentation disorders in the young primigravida.

The fetus is exposed to high plasma concentrations of unbound estrogens and progesterone throughout pregnancy. However, secretory or decidual changes in the fetal uterus occur relatively infrequently before birth, suggesting a variable endometrial progesterone response at the time of birth. Arguably, partial progesterone resistance that persists into adolescent years may compromise the physiological transformation of the spiral arteries and predispose for defective placentation in the case of pregnancy. Decidualization of the endometrial stromal compartment and junctional zone myometrium precedes trophoblast invasion. It represents the first step in the process of spiral artery remodeling needed to establish effective uteroplacental blood flow by midpregnancy. The major obstetric syndromes caused by impaired placental bed spiral artery remodeling are prevalent in teenage pregnancies, including preeclampsia, fetal growth restriction, and spontaneous preterm labor. Preconditioning of the uterus in response to cyclic menstruation during adolescence may be critical to achieve full uterine responsiveness to hormonal cues. Understanding the mechanisms of functional maturation of the uterus during the early reproductive years may yield novel insights into the major obstetric syndromes.

Pathophysiology proposed as the basis for modern management of the ovarian endometrioma.

Present management of the ovarian endometrioma focuses on the size of the cyst and dictates that surgery should not be performed unless this exceeds 3 cm, which neglects the complex pathology of this condition. Studies of ovaries with the endometrioma in situ show progressive smooth muscle cell metaplasia and fibrosis of the cortical layer as the main ovarian lesion. There is no correlation between the size of the endometrial cyst and the degree of ovarian pathology: it is the mere presence of an ovarian endometrioma that has a detrimental impact on the cortical layer's follicle reserve. Cystectomy in young patients with an endometrioma may be particularly detrimental to follicle reserve, with the ovarian parenchyma loss at the time of surgery being related to the cyst's diameter. An underutilized diagnostic procedure, transvaginal hydrolaparoscopy with in-situ inspection of the cyst wall by ovarioscopy, allows careful diagnosis of ovarian pathology and selection of appropriate surgery with minimal invasiveness. Thus, available evidence shows that expectant management may not be the best choice when an endometrioma is suspected. On the contrary, early diagnosis through a minimally invasive technique, followed by early ablative surgery whenever indicated, represents the management of choice to preserve normal ovarian function. Present management of ovarian endometriomata is based on the size of the cyst and dictates that surgery should not be performed unless this exceeds 3cm. We argue that this approach neglects the true pathology of the ovary, since pioneers have studied ovaries with the endometrioma in situ and demonstrated that progressive smooth muscle cell metaplasia and fibrosis in the cortical layer constitute the main features of an endometrioma. There is no correlation between the size of the endometrial cyst and the degree of ovarian pathology: it is in the first place the mere presence of an ovarian endometrioma that has a detrimental impact on follicle reserve. It has been shown that cyst ablation in young patients with an endometrioma may be particularly detrimental to follicle reserve. An underutilized diagnostic procedure, transvaginal needle endoscopy with in-situ inspection after injection of saline suspension into the peritoneal cavity (hydrolaparoscopy) allows careful diagnosis of ovarian cortical pathology by colour changes from pearl-white to dark fibrotic. Thus, available evidence shows that expectant management may not be the best choice when an endometrioma is suspected: the delay in diagnosis causes delay in treatment and progression of the process leading to loss of follicles. On the contrary, early diagnosis through a minimally invasive technique, followed by early ablative surgery whenever indicated, represents the management of choice to preserve normal ovarian function.

The history of endometriosis.

A dispute has recently emerged whether early descriptions exist of the condition we name endometriosis. A first question is: 'Who identified endometriosis?' To respond, two non-complementary methods have been employed: searching for ancient descriptions of symptoms associated with endometriosis or, alternatively, identifying researchers who described pathological features we associate with the presence of endometriosis in its various forms. We opted for the latter and found no evidence that in older times anyone delineated the macroscopic features of endometriosis; descriptions of menstrual or cyclic pain cannot be taken as proof of knowledge of what caused it. During the mid-part of the 19th century, Rokitansky had a great intuition: endometrial glands and stroma can be present in ovarian and uterine neoplasias. However, using histological parameters of endometrial structure and activity, the first scientist to delineate peritoneal endometriosis under the name 'adenomyoma' was Cullen. On the other hand, Rokitansky was the first to describe a form of adenomyosis (an adenomatous polyp). Early descriptions of ovarian endometrioma as 'haematomas of the ovary' or 'chocolate cysts' date back to the end of the 19th century. The first mention of an 'ovary containing uterine mucosa' was published in 1899 by Russel, but Sampson was the first to demonstrate specific endometrial activities, such as desquamation at the time of menstruation and decidualization in pregnancy; subsequently, he presented a theory on its pathogenesis.

Neonatal uterine bleeding as antecedent of pelvic endometriosis.

We elaborate on a new theory to explain pelvic endometriosis, including endometriosis in premenarcheal girls, based on the finding that the neonatal endometrium can display secretory activity immediately after birth and, in some cases, changes analogous to those seen at menstruation in adults. The neonatal uterus is therefore capable of shedding its endometrium. Indeed, occult vaginal bleeding occurs in a majority of neonates, although overt bleeding is estimated to occur in only 5% of neonates. This may be due to functional plugging of the endocervical canal in the neonate, which in turn would promote retrograde flux of endometrial cells contained in menstrual debris. Ectopic endometrial implantation in a newborn with hydrometrocolpos has been documented. These data, coupled with the observation of a significantly increased risk of endometriosis in adolescents with cervical outflow obstruction and patent Fallopian tubes, indicate that endometriosis, especially in children and young adolescents, may originate from retrograde uterine bleeding soon after birth.