A New Classification of Benign, Premalignant, and Malignant Endometrial Tissues Using Machine Learning Applied to 1413 Candidate Variables.

Benign normal (NL), premalignant (endometrial intraepithelial neoplasia, EIN) and malignant (cancer, EMCA) endometria must be precisely distinguished for optimal management. EIN was objectively defined previously as a regression model incorporating manually traced histologic variables to predict clonal growth and cancer outcomes. Results from this early computational study were used to revise subjective endometrial precancer diagnostic criteria currently in use. We here use automated feature segmentation and updated machine learning algorithms to develop a new classification algorithm. Endometrial tissue from 148 patients was randomly separated into 72-patient training and 76-patient validation cohorts encompassing all 3 diagnostic classes. We applied image analysis software to keratin stained endometrial tissues to automatically segment whole-slide digital images into epithelium, cells, and nuclei and extract corresponding variables. A total of 1413 variables were culled to 75 based on random forest classification performance in a 3-group (NL, EIN, EMCA) model. This algorithm correctly classifies cases with 3-class error rates of 0.04 (training set) and 0.058 (validation set); and 2-class (NL vs. EIN+EMCA) error rate of 0.016 (training set) and 0 (validation set). The 4 most heavily weighted variables are surrogates of those previously identified in manual-segmentation machine learning studies (stromal and epithelial area percentages, and normalized epithelial surface lengths). Lesser weighted predictors include gland and lumen axis lengths and ratios, and individual cell measures. Automated image analysis and random forest classification algorithms can classify normal, premalignant, and malignant endometrial tissues. Highest predictive variables overlap with those discovered independently in early models based on manual segmentation.

Congruence Between 1994 WHO Classification of Endometrial Hyperplasia and Endometrial Intraepithelial Neoplasia System.

OBJECTIVES: To assess congruence between World Health Organization (WHO) 1994 and endometrial intraepithelial neoplasia (EIN) classification systems of endometrial hyperplasia. METHODS: Systematic review and meta-analysis were performed by searching electronic databases for studies that classified endometrial hyperplasia according to both WHO 1994 and EIN systems. Congruence was based on the rate of specimens classified as EIN in WHO categories, which should be virtually 0.000 in nonatypical hyperplasia (NAH) and 1.000 in atypical hyperplasia (AH). Subgroup analyses were performed based on architecture complexity. RESULTS: Eight studies with 1,352 hyperplasias were included. Congruence with EIN criteria was fair in NAH (0.241) and moderate in AH (0.815). Subgroup analyses of NAH showed high congruence in simple NAH (0.065), null in complex NAH (0.517), null in simple AH (0.148), and high in complex AH (0.901). CONCLUSIONS: WHO 1994 system is not congruent with the EIN system and cannot be directly translated into a dual classification.

Guideline No. 390-Classification and Management of Endometrial Hyperplasia.

OBJECTIVE: The aim of this guideline is to aid primary care physicians and gynaecologists in the initial evaluation of women with suspected endometrial hyperplasia, to recommend the use of the 2014 World Health Organization classification for endometrial hyperplasia by all health care providers, and to guide the optimal treatment of women diagnosed with endometrial hyperplasia. INTENDED USERS: Physicians, including gynaecologists, obstetricians, family physicians, general surgeons, emergency medicine specialists; nurses, including registered nurses and nurse practitioners; medical trainees, including medical students, residents, and fellows; and all other health care providers. TARGET POPULATION: Adult women (18 years and older) presenting with suspected or confirmed endometrial hyperplasia. OPTIONS: The discussion relates to the medical therapy as well as surgical treatment options for women with and without atypical endometrial hyperplasia. EVIDENCE: For this guideline, relevant studies were searched in PubMed, Cochrane Wiley, and the Cochrane Systematic Reviews using the following terms, either alone or in combination, with the search limited to English language materials, human subjects, and published since 2000: (endometrial hyperplasia, endometrial intraepithelial neoplasia, endometrial sampling, endometrial curettage, diagnosis) AND (treatment, progestin therapy, surgery, LNG-IUS, aromatase inhibitors, metformin ), AND (obesity). The search was performed in April 2018. Relevant evidence was selected for inclusion in the following order: meta-analyses, systematic reviews, guidelines, randomized controlled trials, prospective cohort studies, observational studies, non-systematic reviews, case series, and reports. Additional significant articles were identified through cross-referencing the identified reviews. The total number of studies identified was 2152, and 82 studies were included in this review. VALIDATION METHODS: The content and recommendations were drafted and agreed upon by the authors. The Executive and Board of the Society of Gynecologic Oncology of Canada reviewed the content and submitted comments for consideration, and the Board of the Society of Obstetricians and Gynaecologists of Canada approved the final draft for publication. The quality of evidence was rated using the criteria described in the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology framework. The interpretation of strong and weak recommendations was also included. The Summary of Findings is available upon request. BENEFITS, HARMS, AND/OR COSTS: It is expected that this guideline will benefit women with endometrial hyperplasia. This should guide patient informed consent before both medical and surgical management of this condition. GUIDELINE UPDATE: Evidence will be reviewed 5 years after publication to decide whether all or part of the guideline should be updated. However, if important new evidence is published prior to the 5-year cycle, the review process may be accelerated for a more rapid update of some recommendations. SUMMARY STATEMENTS: RECOMMENDATIONS.

Endometrial hyperplasia and progression to cancer: which classification system stratifies the risk better? A systematic review and meta-analysis.

PURPOSE: Benign and precancerous endometrial hyperplasias (EH) are differentiated thorough two possible histomorphologic classifications: WHO (adopting the subjective evaluation of cytologic atypia) and EIN (adopting several histomorphologic parameters, evaluable subjectively, or objectively with a computerized analysis calculating a prognostic score, the D score). ACOG recommends the use of EIN system although no distinction was made between objective assessment (not widely available), and subjective assessment (more applicable in the common practice). Moreover, it is still unclear if subjective EIN system is actually preferable to WHO classification. We aimed to assess the reliability of WHO system, D score and subjective EIN system in stratifying the risk of progression to cancer in EH. METHODS: MEDLINE, EMBASE, Web of Sciences, Scopus, ClinicalTrial.gov, OVID, Cochrane Library and Google Scholar were searched for relevant articles from the inception to August 2018. All studies assessing the rates of progression of EH to cancer were included. RESULTS: Twelve cohort studies and one case-control study, assessing 3629 EH, were included. Relative risk (RR) for cancer progression was calculated with 95% confidence interval (CI), and results were compared using Chi-square test (significant p value < 0.05). WHO system showed a RR of 8.74 (95% CI 6.66-11.47). Objective D score showed a RR of 29.22 (95% CI 13.24-64.51), significantly higher than WHO (p = 0.005). Subjective EIN system showed a RR of 19.37 (95% CI 5.86-64.01), intermediate between WHO and D score, without significant differences (p = 0.20 and p = 0.57, respectively). CONCLUSION: Objective EIN criteria with D score are significantly more reliable than WHO criteria in stratifying the risk of progression of EH to cancer. Subjective EIN criteria did not show significant superiority over WHO instead. Further studies are necessary to determine if subjective EIN system should replace WHO system in the routine diagnosis of EH.

Complexity of glandular architecture should be reconsidered in the classification and management of endometrial hyperplasia.

The 2014 World Health Organization (WHO) classification of endometrial hyperplasia (EH) defines premalignant EH based on only cytologic atypia, disregarding architecture complexity. We aimed to assess the impact of architecture complexity on the risk of cancer in non-atypical EH. A systematic review and meta-analysis was performed by searching electronic databases form their inception to October 2018. All studies assessing the rates of progression to cancer in non-atypical EH (simple vs complex) were included. Pooled relative risk (RR) for cancer progression was calculated; a p-value < 0.05 was considered significant. Eight studies with 1066 women were included. The risk for progression of non-atypical EH to cancer was significantly higher in complex EH than in simple EH (p < 0.0001), with an RR of 4.90. In conclusion, the complexity of glandular architecture significantly increases the risk of cancer in non-atypical EH. Complex non-atypical EH may be regarded as a low-risk premalignant lesion rather than a benign condition.

Endometrial hyperplasia and the risk of coexistent cancer: WHO versus EIN criteria.

Endometrial hyperplasia (EH) is classified into benign and precancerous according to two different histomorphological systems: the World Health Organisation (WHO) system (based on the subjective evaluation of cytological atypia) and the endometrial intraepithelial neoplasia (EIN) system (based on a combination of several parameters that are assessable subjectively, or objectively through computerised analysis). The American College of Obstetricians and Gynecologists recommends use of the EIN system. Nonetheless, a higher prognostic value for EIN criteria was demonstrated only with the objective assessment, which is not routinely applicable. The aim of this study was to evaluate which of the subjective classifications of EH (WHO or EIN) has better prognostic value, by assessing the risk of coexistent cancer. Electronic databases were searched for relevant articles from the inception of the databases to July 2018. All studies assessing the presence of cancer on hysterectomy specimens after a preoperative histological diagnosis of EH were included. Odds ratios (ORs), sensitivity and specificity were calculated with 95% confidence intervals (CIs). Sixteen cohort studies and three case-control studies, assessing 2582 EHs, were included. The WHO criteria showed an OR of 11.15 (95% CI 7.65-16.24), a sensitivity of 0.86 (95% CI 0.82-0.90) and a specificity of 0.67 (95% CI 0.64-0.70) for coexistent cancer. The subjective EIN system showed a similar OR (11.85, 95% CI 4.91-28.62; P = 0.90), higher sensitivity (0.98, 95% CI 0.94-0.99), and lower specificity (0.29, 95% CI 0.24-0.34). The WHO system and the subjective EIN system have similar prognostic values. However, the EIN criteria appear to be more sensitive and thus more suitable for selecting women who need to be treated, whereas the WHO criteria, based on cytological atypia, seem to be more specific for lesions at higher risk of cancer. Therefore, integration of the EIN system with cytological atypia should be considered.

An audit of endometrial hyperplasias at the Lagos University Teaching Hospital.

INTRODUCTION: There has been much controversy and confusion surrounding the endometrial hyperplasias stemming from the use of a wide variety of terminologies and also from the pathophysiologic mechanisms underlying the various entities. The current classification by the World Health Organization (WHO) published in 2014 clarifies these issues. OBJECTIVE: The aim of this study, therefore, was to audit and standardize cases of endometrial hyperplasia diagnosed in our institution from 2007 to 2011. MATERIALS AND METHODS: The slides and request forms of cases diagnosed as endometrial hyperplasias at the Department of Anatomic and Molecular Pathology from January 1, 2007, to December 31, 2011 were retrieved, reviewed, and reported according to the WHO 2014 classification scheme. RESULTS: Hyperplasia without atypia accounted for the vast majority of cases (95.5%) and was the most common in the 5th decade. Concordance rates of 74.5% and 100% were found between endometrial hyperplasias without atypia and atypical hyperplasias with their previous diagnoses, respectively. CONCLUSION: The WHO classification scheme standardizes and simplifies the terminology used in the diagnosis of endometrial hyperplasias, while reflecting, at the same time, the current understanding of genetic changes that provide information necessary for prognostication and treatment.

[Pitfalls in the histopathological diagnostics of endometrial carcinoma and its precursors : Clinically relevant differential diagnoses, avoidance of false positive diagnoses]. / Fallstricke bei der histopathologischen Diagnostik des Endometriumkarzinoms und seiner Vorstufen : Klinisch wichtige Differenzialdiagnosen, Vermeidung falsch-positiver Diagnosen.

Making an incorrect histopathological diagnosis of an endometrial lesion may lead to unwanted loss of fertility and therapy-associated morbidity; therefore, endometrial carcinomas need to be correctly typed and differentiated from hyperplastic precursors, benign lesions and artifacts. Typical diagnostic pitfalls are described in this article. Misdiagnosing endometrial lesions can be avoided by paying thorough attention to gross as well as microscopic features and by taking crucial differential diagnoses into consideration. These are, in particular, well-differentiated endometrioid adenocarcinoma of the endometrium versus atypical endometrial hyperplasia, myoinvasive endometrioid adenocarcinoma versus atypical polypoid adenomyoma and endometrioid carcinoma versus serous carcinoma of the endometrium with a predominantly glandular pattern. It is also important to consider the possibility of a false positive diagnosis of atypical endometrial hyperplasia or carcinoma in cases of biopsy-induced artifacts.

Therapeutic options for management of endometrial hyperplasia.

Endometrial hyperplasia (EH) comprises a spectrum of changes in the endometrium ranging from a slightly disordered pattern that exaggerates the alterations seen in the late proliferative phase of the menstrual cycle to irregular, hyperchromatic lesions that are similar to endometrioid adenocarcinoma. Generally, EH is caused by continuous exposure of estrogen unopposed by progesterone, polycystic ovary syndrome, tamoxifen, or hormone replacement therapy. Since it can progress, or often occur coincidentally with endometrial carcinoma, EH is of clinical importance, and the reversion of hyperplasia to normal endometrium represents the key conservative treatment for prevention of the development of adenocarcinoma. Presently, cyclic progestin or hysterectomy constitutes the major treatment option for EH without or with atypia, respectively. However, clinical trials of hormonal therapies and definitive standard treatments remain to be established for the management of EH. Moreover, therapeutic options for EH patients who wish to preserve fertility are challenging and require nonsurgical management. Therefore, future studies should focus on evaluation of new treatment strategies and novel compounds that could simultaneously target pathways involved in the pathogenesis of estradiol-induced EH. Novel therapeutic agents precisely targeting the inhibition of estrogen receptor, growth factor receptors, and signal transduction pathways are likely to constitute an optimal approach for treatment of EH.

Therapeutic options for management of endometrial hyperplasia / 부인종양

Endometrial hyperplasia (EH) comprises a spectrum of changes in the endometrium ranging from a slightly disordered pattern that exaggerates the alterations seen in the late proliferative phase of the menstrual cycle to irregular, hyperchromatic lesions that are similar to endometrioid adenocarcinoma. Generally, EH is caused by continuous exposure of estrogen unopposed by progesterone, polycystic ovary syndrome, tamoxifen, or hormone replacement therapy. Since it can progress, or often occur coincidentally with endometrial carcinoma, EH is of clinical importance, and the reversion of hyperplasia to normal endometrium represents the key conservative treatment for prevention of the development of adenocarcinoma. Presently, cyclic progestin or hysterectomy constitutes the major treatment option for EH without or with atypia, respectively. However, clinical trials of hormonal therapies and definitive standard treatments remain to be established for the management of EH. Moreover, therapeutic options for EH patients who wish to preserve fertility are challenging and require nonsurgical management. Therefore, future studies should focus on evaluation of new treatment strategies and novel compounds that could simultaneously target pathways involved in the pathogenesis of estradiol-induced EH. Novel therapeutic agents precisely targeting the inhibition of estrogen receptor, growth factor receptors, and signal transduction pathways are likely to constitute an optimal approach for treatment of EH.

Can malignant potential of endometrial polyps be determined by incorporating the endometrial intraepithelial neoplasia (EIN) classification?

OBJECTIVE: The reported frequency of malignant or premalignant changes confined to endometrial polyps (EP) is 0.5-6%. The management of atypical endometrial hyperplasia (AEH) confined to EP is not yet established. Recently, an alternative pathological nomenclature has emerged using the term endometrial intraepithelial neoplasia (EIN) instead of atypia. The objective of this study was to evaluate the safety of conservative hysteroscopic resection of endometrial polyps with AEH or EIN. METHODS: Retrospective cohort study of all cases of hysteroscopic resections of EP was performed at a single center between the years 2000-2011. All patients with a pathologic diagnosis of AEH in EP were included. A post-hoc revision of the pathologic specimens was made according to the EIN classification. RESULTS: Of the 32 patients with AEH in EP, 25 had normal endometrial curetting. Even with AEH confined to EP, 12 cases (48%) showed AEH (11 cases) or carcinoma (1 case) in the hysterectomy specimens. EIN in EP (14 cases) was correlated with 57% of diagnosis of EIN or carcinoma in the uterus; whereas in the absence of EIN in EP only 1 of 9 cases showed EIN in the final pathologic specimen (p=0.002), and none with carcinoma, which yields a PPV of 14% and a NPV of 100%. CONCLUSION: The diagnosis of EIN in EP may be a better predictor than AEH for endometrial involvement with malignant or pre-malignant neoplasms. The safety of conservative hysteroscopic resection of EP with AEH/EIN is questioned.

Management of "Atypical Endocervical Cells" Compared to "Atypical Glandular Cells".

OBJECTIVE: To assess adherence to management guidelines based on the terminology used to describe atypical glandular cells (AGC) on cytology reports. MATERIALS AND METHODS: We analyzed AGC pathology reports from Hartford Hospital, 2004-2007, and identified cases of AGC with the terminology atypical glandular cells or atypical endocervical cells (AEC). We calculated rates of clinical evaluations based on the terminology used to describe the AGC. Statistical analysis was performed using the χ test. RESULTS: Seventy-eight reports contained the terminology AEC and 97 reports contained the terminology AGC. The rate of histologic sampling in women with AEC was lower than in women with AGC (52.6% vs 83.5%; p < .01). Similarly, the rate of comprehensive evaluations was lower (33.3% vs 71.1%; p < .01). Fewer endocervical curettages (47.4% vs 77.3%; p < .01) and fewer endometrial biopsies in women 35 years or older were performed (26.9% vs 69.1%; p < .01) in women with AEC than in women with AGC. CONCLUSIONS: Women with AGC reports containing the term AEC were managed less optimally than those with AGC. These results suggest that the terminology used to describe the finding of atypical glandular cells may influence the clinical evaluation. Clinicians may not recognize AEC as AGCs. Ours results suggest that the terminology atypical endocervical cells should be avoided or accompanied by the terminology atypical glandular cells.

Reproducibility of current classifications of endometrial endometrioid glandular proliferations: further evidence supporting a simplified classification.

AIMS: To compare the reproducibility of the current (2003) World Health Organization (WHO), endometrial intraepithelial neoplasia (EIN) and European Working Group (EWG) classifications of endometrial endometrioid proliferations. METHODS AND RESULTS: Nine expert gynaecological pathologists from Europe and North America reviewed 198 endometrial biopsy/curettage specimens originally diagnosed as low-grade lesions. All observers were asked to classify the cases by using the categories described in each scheme: six for WHO, four for EIN, and three for EWG. The results were evaluated by kappa statistics for more than two observations. The analysis was repeated using only two major categories (benign versus atypical/carcinoma). Both the WHO and EIN classifications showed poor interobserver agreement (κ = 0.337 and κ = 0.419, respectively), whereas the EWG classification showed moderate agreement (κ = 0.530). Full agreement between pathologists occurred in only 28% for the WHO classification, 39% for the EIN classification, and 59% for the EWG classification. With only two diagnostic categories, kappa values increased in all classifications, but only the EWG classification reached a substantial level of agreement (κ = 0.621); similarly, full agreement among all pathologists increased to 70% for the WHO classification, 69% for the EIN classification, and 72% for the EWG classification. CONCLUSIONS: A two-tier classification of endometrial endometrioid proliferative lesions improves reproducibility, and should be considered for the diagnosis of endometrial biopsy/curettage specimens.

Endometrial Intraepithelial Neoplasia (EIN) in endometrial biopsy specimens categorized by the 1994 World Health Organization classification for endometrial hyperplasia.

Our study is to determine the presence of endometrial intraepithelial neoplasia (EIN) in endometrial biopsy specimens classified by the 1994 World Health Organization (WHO) criteria for endometrial hyperplasia. Endometrial biopsy specimens that were stained with hematoxylin and eosin (HE) were examined and categorized by the WHO 1994 criteria and for the presence of EIN as defined by the International Endometrial Collaborative Group. ß-catenin expression was examined by immunohistochemistry. A total of 474 cases of HE stained endometrial biopsy tissues were reviewed. There were 379 cases of simple endometrial hyperplasia, 16 with simple atypical endometrial hyperplasia, 48 with complex endometrial hyperplasia, and 31 with complex atypical endometrial hyperplasia. Among the 474 endometrial hyperplasia cases, there were 46 (9.7%) that were classified as EIN. Of these 46 cases, 11(2.9%) were classified as simple endometrial hyperplasia, 1 (6.3%) as simple atypical endometrial hyperplasia, 6 (12.5%) as complex endometrial hyperplasia, and 28 (90.3%) as complex atypical endometrial hyperplasia. EIN was associated with a higher rate of ß-catenin positivity than endometrium classified as benign hyperplasia (72% vs. 22.5%, respectively, P < 0.001), but a lower rate than endometrial adenocarcinoma (72% vs. 96.2%, respectively, P < 0.001). In benign endometrial hyperplasia, high ß-catenin expression was noted in the cell membranes, whereas in EIN and endometrial adenocarcinoma high expression was noted in the cytoplasm. In conclusion, EIN is more accurate than the WHO classification for the diagnosis of precancerous lesions of the endometrium.

Endocervical glandular lesions exhibiting gastric differentiation: an emerging spectrum of benign, premalignant, and malignant lesions.

A variety of benign and malignant endocervical glandular lesions exhibiting gastric differentiation has been described in the past decade that has resulted in the concept of an important category of cervical adenocarcinoma which is unrelated to human papillomavirus (HPV). Both minimal deviation adenocarcinoma (MDA), also known as adenoma malignum, and the benign lesion lobular endocervical glandular hyperplasia (LEGH), have been known for some time to exhibit a gastric phenotype and immunophenotype (HIK1083 and/or MUC6 positive). Accumulated evidence suggests that a subset of LEGH (atypical LEGH) exhibits a degree of cytologic and/or architectural atypia which, in some cases, may be associated with and be a precursor of adenocarcinomas exhibiting gastric differentiation, including MDA. Gastric-type adenocarcinoma (GAS), a recently described subtype of cervical adenocarcinoma, is an emerging clinicopathologic entity. These neoplasms exhibit a spectrum of differentiation, including MDA as its very well-differentiated form, are unrelated to HPV, and exhibit aggressive clinical behavior. It is proposed that a LEGH-GAS sequence exists and, from a practical point of view, the development of optimal biomarkers is awaited to assist in early detection of GAS and atypical LEGH, as current HPV-targeted screening generally does not detect these lesions and strategies employing HPV vaccination will not prevent their occurrence. Pathologists should be familiar with the morphologic spectrum of these benign, premalignant, and malignant cervical glandular lesions exhibiting gastric differentiation. They are occasionally associated with Peutz-Jeghers syndrome or are a component of "synchronous mucinous metaplasia and neoplasia of the female genital tract."

Papillary proliferation of the endometrium: a clinicopathologic study of 59 cases of simple and complex papillae without cytologic atypia.

Papillary proliferation of the endometrium (PPE) without cytologic atypia is uncommon and has only been studied in detail by Lehman and Hart in 2001. On histologic examination, PPE ranges from simple papillae with fibrovascular cores, often involving the surface of endometrial polyps, to complex intracystic proliferations; some consider the latter to be analogous to nonatypical complex hyperplasia. To further characterize PPE, with emphasis on the risk of and features associated with concurrent or subsequent neoplasia, the clinicopathologic features of 59 cases without cytologic atypia were studied. The cases were classified into 2 groups according to the degree of architectural complexity and extent of proliferation. Group 1 consisted of those with localized simple papillae. Simple papillae were defined as those with short, predominantly nonbranching stalks; those with occasional secondary branches and/or detached papillae were also included in this group. Localized proliferations were those with 1 or 2 foci involving the surface or the subjacent glands of polyps or nonpolypoid endometrium. Group 2 consisted of those with complex papillae and/or those with diffuse and crowded intracystic papillae. Complex papillae were those with either short or long stalks, with frequent secondary and complex branches. Diffuse proliferation was defined as presence of 3 or more foci within a specimen or involvement of >50% of the endometrial polyp by simple or complex PPE. Any coexistent or subsequent hyperplasia of conventional type (World Health Organization classification) or adenocarcinoma was recorded. The age of patients ranged from 23 to 82 years (median, 53 y); 36 (61%) were postmenopausal. The majority presented with abnormal vaginal bleeding. Sixteen patients (27%) were receiving hormonal preparations including 5 who were treated with a progestogen for preexisting endometrial hyperplasia or low-grade endometrioid adenocarcinoma. The histologic diagnosis of PPE was made in 49 biopsies and in 10 hysterectomy specimens. Thirty-six cases (61%) were classified as group 1 and 23 (39%) as group 2. In 47 cases (80%), there was a coexisting endometrial polyp, 39 (66%) of which were involved by the PPE. Fifty-three cases (90%) had coexisting epithelial metaplastic changes, 41 (77%) of which were involved by the PPE. The most common type of metaplasia was mucinous (41 of 59 cases, or 69%). Follow-up information was known for 46 patients (78%). Coexistent or subsequent nonatypical and atypical hyperplasia was found in 8 (17%) and 6 cases (13%), respectively. In 6 of the 46 cases (13%), a low-grade endometrioid adenocarcinoma was present either in the original specimen or during follow-up. In contrast to group 1 PPE, those with group 2 features were significantly associated with concurrent or subsequent premalignant lesions (nonatypical and atypical hyperplasia) or carcinoma (P<0.0001). This study indicates that localized and architecturally simple PPEs confined to a completely removed polyp are usually associated with a benign outcome and may be appropriately labeled as "benign papillary proliferation of the endometrium." Lesions with architecturally complex papillae, especially when extensive, have an increased risk of concurrent or subsequent endometrial hyperplasia and carcinoma and should probably be regarded as analogous to atypical complex hyperplasia, and the term "complex papillary hyperplasia" is appropriate. As the distinction between simple and complex PPE may be difficult in small endometrial aspirational samples, consideration for curettage should be given to ascertain whether the lesion has been completely removed.

Prediction of coexistent carcinomas risks by subjective EIN diagnosis and comparison with WHO classification in endometrial hyperplasias.

Endometrial intraepithelial neoplasia (EIN) classification is proposed as a new diagnostic system to resolve the limitations of the World Health Organization (WHO) classification in routine practice. Our aim was to find out whether EIN classification excels the WHO classification regarding the accurate prediction of coexisting endometrial carcinomas (EC) in biopsy specimens. We retrospectively re-classified 139 WHO-classified endometrial hyperplasia (EH) cases by subjective EIN diagnosis and compared the incidence of coexisting carcinomas using two classification systems by re-evaluating biopsy and corresponding hysterectomy specimens. Of 139 WHO-classified hyperplasia cases, 36 and 103 were classified as benign and EIN cases, respectively. Forty of 93 cases with atypical EH had EC at hysterectomy as compared with 2/46 cases without atypical EH, while EC was detected in 42/103 cases with EIN, and in 0 of 36 cases without EIN. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for atypical EH vs. non-atypical EH in biopsy specimen was 95.2%, 45.4%, 43.0% and 95.7%, respectively. For EIN vs. benign, the sensitivity was 100% and the specificity was 37.1%. The incidence of coexisting carcinomas in EIN cases was similar to that in atypical EH cases. However, regarding the exclusion of coexisting carcinomas, EIN criteria of benign lesions excelled the WHO criteria of non-atypical EH/CH.

Assessing endometrial hyperplasia and carcinoma treated with progestin therapy.

The effects of increased amounts of progesterone on the endometrium, including such features as eosinophilic cytoplasmic metaplasia, glandular atrophy, and decidualized stroma, are well-known among surgical pathologists. These changes are typically seen as secondary effects of pregnancy or exogenous hormone therapy for birth control purposes or abnormal bleeding. Treatment with progesterone has become a viable alternative to hysterectomy in some patients with complex atypical hyperplasia (CAH) and well-differentiated endometrial carcinoma (WDC), especially those who are poor surgical candidates or those wishing to preserve fertility. To date, only 1 study has specifically examined the effects of progestin therapy on patients with a previous diagnosis of CAH or WDC. That study proposed a classification scheme for the assessment of treated CAH and WDC. The authors concluded that after 6 months of treatment, endometrial biopsy findings of persistent cytologic atypia and architectural abnormalities were associated with treatment failure. This current study aims to assess the previously proposed criteria in a cohort of 30 patients (18 with a diagnosis of CAH and 12 with a diagnosis of WDC), and determine the usefulness of these criteria in clinical practice. Our study confirms that cytologic atypia after 6 months of therapy is strongly associated with treatment failure, and should be an indication to pursue definitive surgical treatment in these patients.

Recommendation for the collection and analysis of endometrial biopsies for hormone therapies.

The assessment of endometrial safety is one of the key requirements for the clinical development of new products for hormone therapy (HT) to treat menopausal symptoms in women who have a uterus. Both the Food and Drug Administration (FDA) in the United States and the European Medicines Agency (EMA) provide detailed guidance on the requirements for the evaluation of biopsies to prove endometrial safety. However, there are some discrepancies between the European and the US requirements, making it difficult to fulfil both guidelines simultaneously. In order to facilitate multinational clinical trials performed within clinical programs to develop novel HT products, we developed an approach considering both guidance documents as far as possible and proposed solutions for issues that are inconsistently described in these guidelines. A table with the required sample sizes is given. Our recommendation for a unified approach for the estimation of the hyperplasia rate for hormone therapies fulfils the intent of the recommendations of both the FDA and the EMA and thus leads to a globally harmonized drug development for hormone therapies.