Description of a Novel System for Grading of Endometrial Carcinoma and Comparison With Existing Grading Systems

Practical Updates and Diagnostic Challenges in Endometrial Carcinoma

CONTEXT.—

Clinical management of endometrial carcinoma largely depends on the morphologic parameters ascertained based on the pathologic evaluation of surgical resection specimens. However, there are numerous controversial and nonstandardized aspects of both the macroscopic and microscopic assessment of surgical specimens, including grossing, adequate sampling, diagnosis, staging, reporting, and ancillary testing.

OBJECTIVE.—

To provide a comprehensive practical review of standardized grossing, key morphologic findings for reporting and staging, and diagnostic and prognostic use of ancillary testing in endometrial carcinomas.

DATA SOURCES.—

The existing literature, recommendations of the International Society of Gynecological Pathologists, and specialty consensus guidelines.

CONCLUSIONS.—

This review article summarizes important aspects of the grossing and sampling of surgical resection specimens for microscopic examination, key morphologic parameters that are required for reporting and staging, and morphologic features and immunoprofiles helpful in the differential diagnosis of low-grade and high-grade endometrial carcinomas, as well as the current status of the molecular classification of endometrial carcinoma and human epidermal growth factor receptor 2 testing in serous carcinoma. The information presented herein can be helpful in overcoming diagnostic challenges and issues related to the pathology reporting of endometrial carcinoma to practicing anatomic pathologists.

Compound AC1Q3QWB upregulates CDKN1A and SOX17 by interrupting the HOTAIR-EZH2 interaction and enhances the efficacy of tazemetostat in endometrial cancer

Endometrial cancer (EC) is a common malignancy of the female reproductive system, with an escalating incidence. Recurrent/metastatic EC presents a poor prognosis. The interaction between the long non-coding RNA (lncRNA) HOTAIR and the polycomb repressive complex 2 (PRC2) induces abnormal silencing of tumor suppressor genes, exerting a pivotal role in tumorigenesis. We have previously discovered AC1Q3QWB (AQB), a small-molecule compound targeting HOTAIR-EZH2 interaction. In the present study, we unveil that AQB selectively hampers the interaction between HOTAIR and EZH2 within EC cells, thus reversing the epigenetic suppression of tumor suppressor genes. Furthermore, our findings demonstrate AQB's synergistic effect with tazemetostat (TAZ), an EZH2 inhibitor, significantly boosting the expression of CDKN1A and SOX17. This, in turn, induces cell cycle arrest and impedes EC cell proliferation, migration, and invasion. In vivo experiments further validate AQB's potential by enhancing TAZ's anti-tumor efficacy at lower doses. Our results advocate AQB, a recently discovered small-molecule inhibitor, as a promising agent against EC cells. When combined with TAZ, it offers a novel therapeutic strategy for EC treatment.

Recent Advances in the Classification of Gynecological Tract Tumors: Updates From the 5th Edition of the World Health Organization "Blue Book"

CONTEXT.—

The World Health Organization Classification of Tumours: Female Genital Tract Tumors, 5th edition, published in September 2020, comes 6 years after the 4th edition, and reflects the monumental leaps made in knowledge about the biology of gynecological tumors. Major changes include revised criteria for the assignment of the site of origin of ovarian and fallopian tube tumors, a revision in the classification of squamous and glandular lesions of the lower genital tract based on human papillomavirus association, and an entire chapter devoted to genetic tumor syndromes. This article highlights the changes in the 5th edition relative to the 4th edition, with a focus on areas of value to routine clinical practice.

OBJECTIVE.—

To provide a comprehensive update on the World Health Organization classification of gynecological tumors, highlighting in particular updated diagnostic criteria and terminology.

DATA SOURCES.—

The 4th and 5th editions of the World Health Organization Classification of Tumours.

CONCLUSIONS.—

The World Health Organization has made several changes in the 5th edition of the update on female genital tumors. Awareness of the changes is needed for pathologists' translation into contemporary practice.

Data Set for the Reporting of Ovarian, Fallopian Tube and Primary Peritoneal Carcinoma: Recommendations From the International Collaboration on Cancer Reporting (ICCR)

The move toward consistent and comprehensive surgical pathology reports for cancer resection specimens has been a key development in supporting evidence-based patient management and consistent cancer staging. The International Collaboration on Cancer Reporting (ICCR) previously developed a data set for reporting of the ovarian, fallopian tube and primary peritoneal carcinomas which was published in 2015. In this paper, we provide an update on this data set, as a second edition, that reflects changes in the 2020 World Health Organization (WHO) Classification of Female Genital Tumours as well as some other minor modifications. The data set has been developed by a panel of internationally recognized expert pathologists and a clinician and consists of "core" and "noncore" elements to be included in surgical pathology reports, with detailed commentary to guide users, including references. This data set replaces the widely used first edition, and will facilitate consistent and accurate case reporting, data collection for quality assurance and research, and allow for comparison of epidemiological and pathologic parameters between different populations.

Data Set for the Reporting of Endometrial Cancer: Recommendations From the International Collaboration on Cancer Reporting (ICCR)

Endometrial cancer is one of the most common cancers among women. The International Collaboration on Cancer Reporting (ICCR) developed a standardized endometrial cancer data set in 2011, which provided detailed recommendations for the reporting of resection specimens of these neoplasms. A new data set has been developed, which incorporates the updated 2020 World Health Organization Classification of Female Genital Tumors, the Cancer Genome Atlas (TCGA) molecular classification of endometrial cancers, and other major advances in endometrial cancer reporting, all of which necessitated a major revision of the data set. This updated data set has been produced by a panel of expert pathologists and an expert clinician and has been subject to international open consultation. The data set includes core elements which are unanimously agreed upon as essential for cancer diagnosis, clinical management, staging, or prognosis and noncore elements which are clinically important, but not essential. Explanatory notes are provided for each element. Adoption of this updated data set will result in improvements in endometrial cancer patient care.

Microcystic, elongated and fragmented (MELF) pattern in endometrial carcinoma: clinicopathologic analysis and prognostic implications

To assess the clinical value of microcystic, elongated, and fragmented (MELF) pattern in Chinese patients with endometrial endometrioid carcinoma. A total of 189 patients with endometrial endometrioid carcinoma were retrospectively analyzed in Peking University Third Hospital from January 2017 to December 2019. We analyzed the association of MELF pattern with the histopathologic data and prognosis of the patients, while immunohistochemistry was performed. The frequency of MELF pattern was 17.99% (34/189). MELF pattern was associated significantly with tumor size, myometrial invasion, histological grade, International Federation of Gynecology and Obstetrics stages, lymphovascular space invasion, and lymph node metastasis. According to multivariate logistic regression analysis, lymphovascular space invasion [95% confidence interval 1.021-48.485, P = .048] was a significant predictor of lymph node involvement. However, MELF pattern was not a significant predictor (95% confidence interval 0.054-2.279, P = .400). Loss of expression for mismatch repair proteins was observed in 10 MELF + cases (29.41%) and 54 MELF- cases (34.84%), respectively. All patients were followed up for 36.8 ± 8.9 months (18-54 months). Only 1 patient with MELF pattern was diagnosed with vaginal recurrence 28 months after the surgery. MELF pattern was associated with adverse histologic findings in endometrial endometrioid carcinomas. However, MELF pattern was statistically not a valuable predictor of lymph node metastasis and it needs more studies to show whether MELF pattern has an impact on the prognosis of patients with endometrial endometrioid carcinoma. MELF pattern may be important for identifying those patients who need comprehensive staging surgery.

The Roles of TP53 and FGFR2 in Progress Made Treating Endometrial Cancer

The morbidity and mortality caused by endometrial cancer (EC) is still rising worldwide. In recent years, a new system of tumor stratification has been proposed based on POLE-mutational status, TP53, and microsatellite stability status. The aim of the study was to analyze a vast panel on the genes potentially involved in the genesis of endometrial cancer in the Polish population. One hundred and three white female patients with confirmed endometrial cancer were enrolled on the study. We performed sequencing using the Hot Spot Illumina panel and microsatellite stability with immunohistochemistry. We confirmed a key role of the TP53 mutation in progress to high-grade EC and parallelly some role of FGFR2 mutation. Moreover, our data present a vast landscape of mutations in EC and their polymorphism. We reported the meaning of FGFR2 mutation and TP53 (high copy number) in high-grade ECs. Our observation in MSI contribution is comparable with other studies. Finally, we see a strong need for the implementation of the TCGA classification.

A combination of immunohistochemical markers, MUC1, MUC5AC, PAX8 and growth pattern for characterization of mucinous neoplasm of the ovary

OBJECTIVE

Because mucinous carcinomas are rare tumors that affect several organ sites and are known to originate from different tissues, leading to frequent misdiagnoses, the objective was to characterize the differences between primary mucinous tumors of the ovary and metastatic mucinous cancer to the ovary by studying the expression pattern of several candidate biomarkers.

METHODS

Tissue samples of mucinous histology were obtained between 1985 and 2015. Individual ovary and colon tissue samples were analyzed, including standard (PAX8, CK20, CK7, CDX2, SATB2, estrogen/progesterone) and new (MUC1, MUC5AC) biomarkers, which were then scored for immunoreactivity semi-quantitatively.

RESULTS

The study cohort included 98 mucinous tumor samples, including benign mucinous cystadenoma (n=24), mucinous borderline tumors (n=24), mucinous carcinomas (n=40), and metastatic mucinous ovarian carcinomas (n=10). A strong positive correlation was found between PAX8 scoring (p=0.003), CK7 scoring (p=0.0001), and MUC1 scoring (p=0.001) in primary mucinous ovarian cancer. Tumors of increasing invasiveness were analyzed and a significant decrease in the scoring of MUC5AC (p=0.001) was observed, with a stronger expression in adenomas (87%) and borderline tumors (75%), and a lower expression in mucinous cancers (42%). Patients survived significantly longer when their tumors expressed high PAX8 and showed an expansile invasion pattern (p=0.005 and p=0.015, respectively) compared with patients with PAX8-negative tumors and destructive invasion pattern.

CONCLUSION

The study data support the diagnostic value of MUC1 as a new biomarker to differentiate between primary and metastatic mucinous ovarian cancer. In addition, the tumor growth pattern along with the PAX8 immunophenotype might represent potential prognostic biomarkers for primary mucinous ovarian carcinomas.

Risk Stratification of Endometrial Cancer Patients: FIGO Stage, Biomarkers and Molecular Classification

Endometrial cancer (EC) is the most common gynaecologic malignancy in developed countries. The main challenge in EC management is to correctly estimate the risk of metastases at diagnosis and the risk to develop recurrences in the future. Risk stratification determines the need for surgical staging and adjuvant treatment. Detection of occult, microscopic metastases upstages patients, provides important prognostic information and guides adjuvant treatment. The molecular classification subdivides EC into four prognostic subgroups: POLE ultramutated; mismatch repair deficient (MMRd); nonspecific molecular profile (NSMP); and TP53 mutated (p53abn). How surgical staging should be adjusted based on preoperative molecular profiling is currently unknown. Moreover, little is known whether and how other known prognostic biomarkers affect prognosis prediction independent of or in addition to these molecular subgroups. This review summarizes the factors incorporated in surgical staging (i.e., peritoneal washing, lymph node dissection, omentectomy and peritoneal biopsies), and its impact on prognosis and adjuvant treatment decisions in an era of molecular classification of EC. Moreover, the relation between FIGO stage and molecular classification is evaluated including the current gaps in knowledge and future perspectives.

Grading of endometrial cancer using 1H HR-MAS NMR-based metabolomics

The tissue metabolomic characteristics associated with endometrial cancer (EC) at different grades were studied using high resolution (400 MHz) magic angle spinning (HR-MAS) proton spectroscopy. The metabolic profiles were obtained from 64 patients (14 with grade 1 (G1), 33 with grade 2 (G2) and 17 with grade 3 (G3) tumors) and compared with the profile acquired from 10 patients with the benign disorders. OPLS-DA revealed increased valine, isoleucine, leucine, hypotaurine, serine, lysine, ethanolamine, choline and decreased creatine, creatinine, glutathione, ascorbate, glutamate, phosphoethanolamine and scyllo-inositol in all EC grades in reference to the non-transformed tissue. The increased levels of taurine was additionally detected in the G1 and G2 tumors in comparison to the control tissue, while the elevated glycine, N-acetyl compound and lactate—in the G1 and G3 tumors. The metabolic features typical for the G1 tumors are the increased dimethyl sulfone, phosphocholine, and decreased glycerophosphocholine and glutamine levels, while the decreased myo-inositol level is characteristic for the G2 and G3 tumors. The elevated 3-hydroxybutyrate, alanine and betaine levels were observed in the G3 tumors. The differences between the grade G1 and G3 malignances were mainly related to the perturbations of phosphoethanolamine and phosphocholine biosynthesis, inositol, betaine, serine and glycine metabolism. The statistical significance of the OPLS-DA modeling was also verified by an univariate analysis. HR-MAS NMR based metabolomics provides an useful insight into the metabolic reprogramming in endometrial cancer.

Improving preoperative diagnosis in endometrial cancer using systematic morphological assessment and a small immunohistochemical panel

Preoperative histopathological classification determines the primary surgical approach in endometrial carcinoma (EC) patients but has only moderate agreement between preoperative and postoperative diagnosis. The aim of the PIpelle Prospective ENDOmetrial carcinoma (PIPENDO) study is to determine whether histopathological assessment and a small panel of diagnostic biomarkers decreases discrepancies between preoperative and postoperative diagnosis in EC. Preoperative endometrial tissue of 378 included patients with EC was stained with 15 different antibodies. Clinically relevant discrepancies in grade or histological subtype between original preoperative and reviewed postoperative diagnosis were observed in 75 (20%) patients. Highest clinically relevant discrepancy was found in grade 2 ECs (20%), compared to 5% and 14% in respectively grade 1 and 3 endometrioid endometrial carcinomas (EECs). A practical two-biomarker panel with PR and p53 improved diagnostic accuracy (AUC = 0.92; 95%CI = 0.88-0.95) compared to solely morphological evaluation (AUC = 0.86). In preoperative high-grade EC, the diagnostic accuracy of histological subtype was improved by a three-immunohistochemical biomarker panel (PR, IMP3, and L1CAM) (AUC = 0.93; 95%CI = 0.88-0.98) compared to solely morphological evaluation (AUC = 0.81). In conclusion to improve correct preoperative diagnosis in EC, we recommend use of a panel of at least two easily accessible immunohistochemical biomarkers (PR and p53), only in grade 2 ECs. Overall, this will reduce clinically relevant discrepancies in tumor grade and subtype with postoperative diagnosis with 6% (from 20% to 14%). Addition of PR, IMP3, and L1CAM for histological subtyping in high-grade EECs resulted in a further decrease in discrepancies with 8% (from 20% to 12%).

Prognostic impact of histological review of high-grade endometrial carcinomas in a large Danish cohort

The aim of this study was to investigate the outcome of histological subtype review of high-grade endometrial carcinoma (EC) and its prognostic impact in a large well-documented Danish nationwide cohort. From the Danish Gynecological Cancer Database (DGCD) 2005-2012 cohort, we included 425 patients with an original diagnosis of high-grade EC, independent of histologic subtype. Of these, at least one hematoxylin and eosin (H&E)-stained slide from 396 cases (93.2%) was available for review. The histologic subtype was reviewed by specialized gynecopathologists blinded to the original diagnosis and clinical outcome. Interobserver variability between original and revised histologic subtypes was analyzed using simple Kappa statistics. Hazard ratios (HR), recurrence-free survival (RFS), and overall survival were calculated for original and revised subtypes, respectively. Overall histologic subtype agreement was moderate (kappa = 0.42) with the highest agreement for endometrioid-type EC (EEC; 75.5%) and serous-type EC (SEC; 63.8%). For clear cell carcinoma and un-/dedifferentiated EC, agreement was significantly lower: 30.1% and 33.3% respectively. Of the 396 reviewed cases, only two (0.5%) were re-classified as low-grade EEC upon revision. Interestingly, GR3 EEC had better RFS than SEC with stronger significance after revision (HR 2.36 (95% CI 1.43-3.89), p = 0.001), compared to original diagnosis (HR 1.74 (95% CI 1.07-2.81), p = 0.024). In conclusion, this study confirmed that pathology review results in substantial shift in histological subtype in high-grade EC. After review, a stronger prognostic benefit for GR3 EEC as compared to other histological subtypes was observed. This work supports maintaining a low threshold for pathology revision of high-grade EC in clinical practice.

Expression of Selected Epithelial-Mesenchymal Transition Transcription Factors in Endometrial Cancer

Endometrial cancer (EC) is the most common gynecologic malignancy in developed countries. The aim of this study was to analyze the expression of SNAIL, SLUG, TWIST1, TWIST2, ZEB1, and ZEB 2 in primary tumor and the correlation with morphological and clinical characteristics of EC. The study included 158 patients with EC after surgical treatments: total hysterectomy and lymphadenectomy. The percentages of EC specimens testing positively for the EMT transcription factors were 84.5% for SNAIL, 92.2% for SLUG, 10.9% for TWIST1, 100% for TWIST2, 89% for ZEB1, and 98% for ZEB2. The expression of SLUG in patients with FIGO stage III or IV, type II EC, myometrial invasion ≥ 50% of the uterine wall thickness, and adnexal involvement and in patients with distant metastases was significantly higher. SLUG and ZEB2 expressions were identified as significant predictors of higher FIGO stages (III or IV) on univariate analysis. The overexpression of SLUG was a significant predictor of more aggressive type II EC, myometrial invasion ≥ 50% of the uterine wall thickness, and distant metastases on both univariate and multivariate analysis. Moreover, the overexpression of SLUG and ZEB2 was shown to be significant predictors of adnexal involvement on univariate analysis. ZEB 2 overexpression was identified in multivariate analysis as another independent predictor associated with a lesser likelihood of type II EC. Both univariate and multivariate analyses demonstrated that SLUG expression was the only predictor of 5-year survival in the study group. The overexpression of SLUG was associated with a significant increase in mortality hazard on univariate analysis and was shown to be a highly significant predictor of death on multivariate analysis. Conclusions. Selected proteins of the EMT pathway play a role in endometrial carcinogenesis; SLUG and ZEB2 expressions in the primary tumor might predict clinical outcomes in EC and drive therapeutic decisions regarding adjuvant treatment in patients with this malignancy.

Prognosis Trend of Grade 2 Endometrioid Endometrial Carcinoma: Toward Grade 1 or 3?

Although the prognostic significance of grade in endometrial cancer is well known, grade 2 cases have not been evaluated separately in most of the previous studies. In this study, we aim to investigate whether the oncologic outcomes of grade 2 endometrioid endometrial carcinomas trend towards grade 1 or 3 tumors. Patients' records and pathological reports were reviewed retrospectively and eligible patients with endometrioid endometrial carcinoma were determined and distributed into 3 groups according to their 1988 International Federation of Gynecology and Obstetrics (FIGO) grade. Groups' characteristics and oncologic outcomes were compared. Differences between grades were tested with z-test and adjusted by Bonferroni method. Kaplan-Meier method was performed for the survival analysis. In total, 776 patients of endometrioid endometrial carcinoma were included in this study. Mean follow-up time was 52 ± 14 months. Patients' mean age was 56.3 ± 10.8 years. Even though grade 2 endometrioid endometrial carcinomas were different from both grade 1 and 3 in terms of the pathological features, survival analyses demonstrated that their oncologic outcomes trended towards grade 1. The grade was determined as an independent prognostic factor for overall survival (OS). The interobserver reproducibility will be improved among pathologists by combining FIGO grade 1 and 2 endometrioid endometrial carcinomas, while prognosis prediction is not likely to be affected.

Endometrial Carcinoma Diagnosis: Use of FIGO Grading and Genomic Subcategories in Clinical Practice: Recommendations of the International Society of Gynecological Pathologists

In this review, we sought to address 2 important issues in the diagnosis of endometrial carcinoma: how to grade endometrial endometrioid carcinomas and how to incorporate the 4 genomic subcategories of endometrial carcinoma, as identified through The Cancer Genome Atlas, into clinical practice. The current International Federation of Gynecology and Obstetrics grading scheme provides prognostic information that can be used to guide the extent of surgery and use of adjuvant chemotherapy or radiation therapy. We recommend moving toward a binary scheme to grade endometrial endometrioid carcinomas by considering International Federation of Gynecology and Obstetrics defined grades 1 and 2 tumors as "low grade" and grade 3 tumors as "high grade." The current evidence base does not support the use of a 3-tiered grading system, although this is considered standard by International Federation of Gynecology and Obstetrics, the American College of Obstetricians and Gynecologists, and the College of American Pathologists. As for the 4 genomic subtypes of endometrial carcinoma (copy number low/p53 wild-type, copy number high/p53 abnormal, polymerase E mutant, and mismatch repair deficient), which only recently have been identified, there is accumulating evidence showing these categories can be reproducibly diagnosed and accurately assessed based on biopsy/curettage specimens as well as hysterectomy specimens. Furthermore, this subclassification system can be adapted for current clinical practice and is of prognostic significance independent of conventional variables used for risk assessment in patients with endometrial carcinoma (eg, stage). It is too soon to recommend the routine use of genomic classification in this setting; however, with further evidence, this system may become the basis for the subclassification of all endometrial carcinomas, supplanting (partially or completely) histotype, and grade. These recommendations were developed from the International Society of Gynecological Pathologists Endometrial Carcinoma project.

Clinical consequences of upfront pathology review in the randomised PORTEC-3 trial for high-risk endometrial cancer

Background

In the PORTEC-3 trial, women with high-risk endometrial cancer (HR-EC) were randomised to receive pelvic radiotherapy (RT) with or without concurrent and adjuvant chemotherapy (two cycles of cisplatin 50 mg/m² in weeks 1 and 4 of RT, followed by four cycles of carboplatin AUC5 and paclitaxel 175 mg/m²). Pathology review was required before patient enrolment. The aim of this analysis was to evaluate the role of central pathology review before randomisation.

Patients and methods

A total of 1295 cases underwent pathology review to confirm HR-EC in the Netherlands (n = 395) and the UK (n = 900), and for 1226/1295 (95%) matching review and original reports were available. In total, 329 of these patients were enrolled in the PORTEC-3 trial: 145 in the Netherlands and 184 in the UK, comprising 48% of the total PORTEC-3 cohort of 686 participants. Areas of discrepancies were evaluated, and inter-observer agreement between original and review opinion was evaluated by calculating the kappa value (κ).

Results

In the 1226 pathology reviews, 6356 selected items were evaluable for both original and review pathology. In 43% of cases at least one pathology item changed after review. For 102 patients (8%), this discrepancy led to ineligibility for the PORTEC-3 trial, most frequently due to differences in the assessment of histological type (34%), endocervical stromal involvement (27%) and histological grade (19%). Lowest inter-observer agreement was found for histological type (κ = 0.72), lymph-vascular space invasion (κ = 0.72) and histological grade (κ = 0.70).

Conclusion

Central pathology review by expert gynaeco-pathologists changed histological type, grade or other items in 43% of women with HR-EC, leading to ineligibility for the PORTEC-3 trial in 8%. Upfront pathology review is essential to ensure enrolment of the target trial-population, and to avoid over- or undertreatment, especially when treatment modalities with substantial toxicity are involved.

This study is registered with ISRCTN (ISRCTN14387080, www.controlled-trials.com) and with ClinicalTrials.gov (NCT00411138).

Relationships of nuclear, architectural and International Federation of Gynecology and Obstetrics grading systems in endometrial cancer

Objective:

To examine correlations among nuclear, architectural, and International Federation of Gynecology and Obstetrics (FIGO) grading systems, and their relationships with lymph node (LN) involvement in endometrioid endometrial cancer.

Material and Methods:

Histopathology slides of 135 consecutive patients were reviewed with respect to tumor grade and LN metastasis. Notable nuclear atypia was defined as grade 3 nuclei. FIGO grade was established by raising the architectural grade (AG) by one grade when the tumor was composed of cells with nuclear grade (NG) 3. Correlations between the grading systems were analyzed using Spearman’s rank correlation coefficients, and relationships of grading systems with LN involvement were assessed using logistic regression analysis.

Results:

Correlation analysis revealed a significant and strongly positive relationship between FIGO and architectural grading systems (r=0.885, p=0.001); however, correlations of nuclear grading with the architectural (r=0.535, p=0.165) and FIGO grading systems (r=0.589, p=0.082) were moderate and statistically non-significant. Twenty-five (18.5%) patients had LN metastasis. LN involvement rates differed significantly between tumors with AG 1 and those with AG 2, and tumors with FIGO grade 1 and those with FIGO grade 2. In contrast, although the difference in LN involvement rates failed to reach statistical significance between tumors with NG 1 and those with NG 2, it was significant between NG 2 and NG 3 (p=0.042). Although all three grading systems were associated with LN involvement in univariate analyses, an independent relationship could not be established after adjustment for other confounders in multivariate analysis.

Conclusion:

Nuclear grading is significantly correlated with neither architectural nor FIGO grading systems. The differences in LN involvement rates in the nuclear grading system reach significance only in the setting of tumor cells with NG 3; however, none of the grading systems was an independent predictor of LN involvement.

Second Opinion Expert Pathology in Endometrial Cancer: Potential Clinical Implications

OBJECTIVE

In cancer patients, the pathology report serves as an important basis for treatment. Therefore, a correct cancer diagnosis is crucial, and diagnostic discrepancies may be of clinical relevance. It was the aim of this study to perform a specialized histopathology review and to investigate potential clinical implications of expert second opinion pathology in endometrial cancer.

METHODS

Patients treated for endometrial carcinoma at the Tübingen University Women's hospital between 2003 and 2013 were identified. Original pathology reports were reviewed, and contributing pathologists were asked to submit original slides and paraffin blocks. Case review was subsequently performed by 3 pathologists specialized in gynecological pathology who were blinded for clinical information. For histological typing, the World Health Organization 2014 classification was used, grading and staging were performed according to International Federation of Gynecology and Obstetrics 2009. Risk assignment was performed based on the 2013 European Society for Medical Oncology clinical practice guidelines.

RESULTS

In 565 of 745 cases, which had originally been diagnosed as endometrial carcinoma, archival histological slides and blocks were available. In 55 (9.7%) of 565 cases, a major diagnostic discrepancy of potential clinical relevance was found after expert review. In 38 of these 55 cases, the diagnostic discrepancy was related to tumor type (n = 24), grade (n = 10) or myoinvasion (n = 4). In 17 cases, the diagnosis of endometrial carcinoma could not be confirmed (atypical hyperplasia, n = 10; endometrial carcinosarcoma, n = 4; neuroendocrine carcinoma, n = 1; leiomyosarcoma, n = 1; atypical polypoid adenomyoma, n = 1). Minor discrepancies not changing risk classification were also noted in 214 (37.9%) of 565, most frequently for grade within the low-grade (G1/G2) category (n = 184).

CONCLUSIONS

A retrospective gynecopathological case review was shown to reveal limited but significant discrepancies in histological diagnoses as well as typing and grading of endometrial carcinomas, some directly impacting clinical management. Second opinion pathology therefore not only helps to improve the quality of translational research study cohorts but might also help to optimize patient care in difficult cases.

[Grading of gynecological tumors : Current aspects]

Histopathological assessment of the tumor grade and cell type is central to the management and prognosis of various gynecological malignancies. Conventional grading systems for squamous carcinomas and adenocarcinomas of the vulva, vagina and cervix are poorly defined. For endometrioid tumors of the female genital tract as well as for mucinous endometrial, ovarian and seromucinous ovarian carcinomas, the 3‑tiered FIGO grading system is recommended. For uterine neuroendocrine tumors the grading system of the gastrointestinal counterparts has been adopted. Uterine leiomyosarcomas are not graded. Endometrial stromal sarcomas are divided into low and high grades, based on cellular morphology, immunohistochemical and molecular findings. A chemotherapy response score was established for chemotherapeutically treated high-grade serous pelvic cancer. For non-epithelial ovarian malignancies, only Sertoli-Leydig cell tumors and immature teratomas are graded. At this time molecular profiling has no impact on the grading of tumors of the female genital tract.

Pathology of Endometrial Carcinoma

On a clinicopathological and molecular level, two distinctive types of endometrial carcinoma, type I and type II, can be distinguished. Endometrioid carcinoma, the typical type I carcinoma, seems to develop through an estrogen-driven "adenoma carcinoma" pathway from atypical endometrial hyperplasia/endometrioid intraepithelial neoplasia (AEH/EIN). It is associated with elevated serum estrogen and high body mass index and expresses estrogen and progesterone receptors. They are mostly low grade and show a favorable prognosis. A subset progresses into high-grade carcinoma which is accompanied by loss of receptor expression and accumulation of TP53 mutations and behaves poorly. Other frequently altered genes in type I carcinomas are K-Ras, PTEN, and ß-catenin. Another frequent feature of type I carcinomas is microsatellite instability mainly caused by methylation of the MLH1 promoter. In contrast, the typical type II carcinoma, serous carcinoma, is not estrogen related since it usually occurs in a small uterus with atrophic endometrium. It is often associated with a flat putative precursor lesion called serous endometrial intraepithelial carcinoma (SEIC). The molecular pathogenesis of serous carcinoma seems to be driven by TP53 mutations, which are present in SEIC. Other molecular changes in serous carcinoma detectable by immunohistochemistry involve cyclin E and p16. Since many of the aforementioned molecular changes can be demonstrated by immunohistochemistry, they are useful ancillary diagnostic tools and may further contribute to a future molecular classification of endometrial carcinoma as recently suggested based on The Cancer Genome Atlas (TCGA) data.

A small multimarker panel using simple immunohistochemistry methods is an adjunct to stage for cutaneous melanoma prognosis

Melanoma is an aggressive cancer. Outcomes can vary significantly for lesions within the same pathological stage - a problem of increasing relevance with the promise of adjuvant treatments on the basis of immune checkpoint modulators and targeted therapies. The use of a panel of prognostic molecular biomarkers as an adjunct to stage represents a possible solution. Immunohistochemistry-based biomarkers offer greater potential for translation into clinical practice than biomarkers utilizing more complex methods. Many immunohistochemistry-based biomarkers have been identified through discovery studies, but rigorous validation of these is scarce. We take the first steps towards validating a combination of three such biomarkers in a prognostic panel - 5hmC, ki-67 and p16. Immunohistochemistry was performed on a cohort of 50 melanomas to determine the expression of 5hmC, ki-67 and p16. 5hmC and p16 showed statistically significant differences in metastasis-free survival between low-score and high-score groups, whereas the use of all three biomarkers together with stage could predict the 5-year metastasis risk more accurately than stage alone. Our results suggest that the use of multimarker panels to improve the accuracy of prognostic predictions is feasible and worthy of further study. We have shown that a small immunohistochemistry-based panel utilizing simple, inexpensive, reproducible methods can be an effective adjunct to stage in prognostic prediction. A follow-up study consisting of a large cohort of melanomas is now indicated to continue the development of the prognostic panel.

Comparative study of different histologic classifications in the degree of differentiation in endometrial adenocarcinoma

PURPOSE

To evaluate the concordance among the available histologic classifications for endometrial adenocarcinoma using interobserver and intraobserver agreement as well as the association of tumor histologic degree in the above mentioned classifications with cellular proliferation measured by Ki-67.

METHODS

Seventy women who underwent surgical treatment of endometrial adenocarcinoma with histologic confirmation of endometrioid type were included in the study. Two experienced pathologists randomly analyzed the slides in 3 distinct timeframes with a maximum of 25 slides/timeframe. Tumor slides were classified according to the degree of differentiation using 4 different classifications: International Federation of Gynecology and Obstetrics (FIGO), modified FIGO, Lax, and Alkushi.

RESULTS

Intraobserver agreement was reasonable for classification of FIGO (k 0.469 and 0.538), very good for modified FIGO (k 0.661 and 0.768), moderate for Lax classification (k 0.496 and 0.466), and moderate/good for Alkushi classification (k 0.528 and 0.736). Interobserver concordance was regular for FIGO classification (k = 0.271 and 0.343), good/moderate for modified FIGO classification (k = 0.661 and 0.522, respectively), regular/moderate for Lax classification (k = 0.258 and 0.465, respectively), and regular for Alkushi classification (k = 0.283 and 0.402).

CONCLUSIONS

The prognostic value of histologic grading in endometrial carcinoma and its importance for a successful therapeutic plan have been documented repeatedly, but the best grading system, in terms of prognostication, reproducibility, ease of use, and universality (e.g., applicability to all tumor cell types), has not been unequivocally defined.

SLUG expression is an indicator of tumour recurrence in high-grade endometrial carcinomas

AIMS

To investigate how SNAIL and SLUG were involved in the nature of high-grade endometrial carcinomas (grade 3 endometrioid carcinoma, serous carcinoma and clear cell carcinoma), we analysed the correlation of their expression status with clinicopathological characteristics and evaluated their prognostic significance.

METHODS AND RESULTS

We performed immunohistochemical staining in 52 high-grade endometrial carcinomas. Expression status of SNAIL and SLUG was classified into a high expression (positive in more than 50% of the tumour cells) and a low expression. Thirteen cases (25%) showed a high expression of SLUG, whereas all 52 cases showed a low expression of SNAIL. High expression of SLUG was correlated significantly with tumour recurrence (P = 0.0203) and aberrant p53 expression (P = 0.000559). Overall survival was worse in patients with high SLUG expression at all stages (P = 0.0327) and in those who underwent adjuvant therapy (P = 0.00963). Among the patients with complete tumour resection, high SLUG expression was associated with worse recurrence-free survival (RFS) in the patients at all stages (P = 0.00264), at stages III/IV (P = 0.0146), and who underwent adjuvant therapy (P = 0.000743). SLUG expression was identified as an independent factor of RFS by multivariate analysis (hazard ratio 5.938, 95% confidence interval 1.251-28.18, P = 0.025).

CONCLUSIONS

SLUG expression could be correlated with TP53 mutational status and could be involved in therapeutic resistance resulting in tumour recurrence. A high expression level of SLUG can be an indicator of recurrence and a therapeutic target for long-term remission in high-grade endometrial carcinomas.

Interobserver Variability in the Diagnosis of Uterine High-Grade Endometrioid Carcinoma

CONTEXT

-Low interobserver diagnostic agreement exists among high-grade endometrial carcinomas.

OBJECTIVE

-To evaluate diagnostic variability in International Federation of Gynecology and Obstetrics (FIGO) grade 3 endometrioid adenocarcinoma (G3EC) in 2 different sign-out practices.

DESIGN

-Sixty-six G3EC cases were identified from pathology archives of Wayne State University (WSU, Detroit, Michigan) (general surgical pathology sign-out) and 65 from Memorial Sloan Kettering Cancer Center (MSK, New York, New York) (gynecologic pathology focused sign-out). Each case was reviewed together by 2 gynecologic pathologists, one from each institution, and classified into the G3EC group or a reclassified group. Clinicopathologic parameters were compared.

RESULTS

-Twenty-five WSU cases (38%) were reclassified as undifferentiated (n = 2), serous (n = 4), mixed endometrioid and serous carcinomas (n = 12), and FIGO grade 2 endometrioid adenocarcinomas with focal marked nuclear atypia (n = 7). Eleven MSK cases (17%) were reclassified as undifferentiated (n = 5), serous (n = 1), mixed endometrioid and serous carcinomas (n = 4), and mixed endometrioid and clear cell carcinomas (n = 1). Agreement rate between original and review diagnosis was 83% (54 of 65) at MSK and 62% (41 of 66) at WSU (P = .01) with an overall rate of 73% (95 of 131). There were more undifferentiated carcinomas at MSK than there were at WSU (45% [5 of 11] versus 8% [2 of 25]; P = .02). There were more grade 2 endometrioid adenocarcinomas with focal, marked nuclear atypia at WSU (28%; 7 of 25) than there were at MSK (0%) (P = .03). Mixed endometrioid and serous carcinoma was the most common misclassified subtype (44%; 16 of 36).

CONCLUSION

-Moderate interobserver variability exists in the diagnosis of G3EC with a significantly greater diagnostic agreement rate in gynecologic pathology-focused sign-out than in general sign-out practice.

Improved Risk Assessment by Integrating Molecular and Clinicopathological Factors in Early-stage Endometrial Cancer-Combined Analysis of the PORTEC Cohorts

PURPOSE

Recommendations for adjuvant treatment for women with early-stage endometrial carcinoma are based on clinicopathologic features. Comprehensive genomic characterization defined four subgroups: p53-mutant, microsatellite instability (MSI), POLE-mutant, and no specific molecular profile (NSMP). We aimed to confirm the prognostic capacity of these subgroups in large randomized trial populations, investigate potential other prognostic classifiers, and integrate these into an integrated molecular risk assessment guiding adjuvant therapy.

EXPERIMENTAL DESIGN

Analysis of MSI, hotspot mutations in 14 genes including POLE, protein expression of p53, ARID1a, β-catenin, L1CAM, PTEN, ER, and PR was undertaken on 947 available early-stage endometrioid endometrial carcinomas from the PORTEC-1 and -2 trials, mostly high-intermediate risk (n = 614). Prognostic value was determined using univariable and multivariable Cox proportional hazard models. AUCs of different risk stratification models were compared.

RESULTS

Molecular analyses were feasible in >96% of the patients and confirmed the four molecular subgroups: p53-mutant (9%), MSI (26%), POLE-mutant (6%), and NSMP (59%). Integration of prognostic molecular alterations with established clinicopathologic factors resulted in a stronger model with improved risk prognostication. Approximately 15% of high-intermediate risk patients had unfavorable features (substantial lymphovascular space invasion, p53-mutant, and/or >10% L1CAM), 50% favorable features (POLE-mutant, NSMP being microsatellite stable, and CTNNB1 wild-type), and 35% intermediate features (MSI or CTNNB1-mutant).

CONCLUSIONS

Integrating clinicopathologic and molecular factors improves the risk assessment of patients with early-stage endometrial carcinoma. Assessment of this integrated risk profile is feasible in daily practice, and holds promise to reduce both overtreatment and undertreatment. Clin Cancer Res; 22(16); 4215-24. ©2016 AACR.

Histopathological features of endometrial carcinomas associated with POLE mutations: implications for decisions about adjuvant therapy

AIMS

To characterize the histomorphological features of endometrial carcinomas (ECs) harbouring polymerase ε (POLE) mutations.

METHODS AND RESULTS

Forty-three ECs with POLE mutations were compared with a cohort of 202 ECs. Most POLE-mutated ECs were endometrioid [34/43 (79%)]; the remaining tumours were mixed [6/43 (14%)], serous [2/43 (5%)], and clear cell [1/43 (2%)]. The endometrioid carcinomas were predominantly International Federation of Gynecology and Obstetrics grade 3 (27/43, 63%). The histotype distribution did not differ from that of control ECs (P = 0.69), but the grade of the EC was higher (P < 0.0005). Both nuclear grade and mitotic index were significantly higher in POLE-mutated ECs than in the comparison cohort. POLE-mutated ECs were associated with peritumoral lymphocytes and numerous tumour-infiltrating lymphocytes. Lymphovascular invasion was present in 20 of 43 tumours. Adjuvant radiotherapy and adjuvant chemotherapy would be offered in up to 80% and 40% of patients, respectively, on the basis of stage, grade, lymphovascular invasion, and histotype.

CONCLUSIONS

POLE-mutated ECs are typically of high grade, with prominent lymphocytic infiltration, but they are not sufficiently distinctive to allow accurate diagnosis based on routine haematoxylin and eosin staining. Even though POLE-mutated tumours are associated with an excellent prognosis, current guidelines for giving adjuvant treatment for EC result in most patients receiving adjuvant therapy.

Data set for reporting of ovary, fallopian tube and primary peritoneal carcinoma: recommendations from the International Collaboration on Cancer Reporting (ICCR)

A comprehensive pathological report is essential for optimal patient management, cancer staging and prognostication. In many countries, proforma reports are used but these vary in their content. The International Collaboration on Cancer Reporting (ICCR) is an alliance formed by the Royal College of Pathologists of Australasia, the Royal College of Pathologists of the United Kingdom, the College of American Pathologists, the Canadian Partnership Against Cancer and the European Society of Pathology, with the aim of developing an evidence-based reporting data set for each cancer site. This will reduce the global burden of cancer data set development and reduplication of effort by different international institutions that commission, publish and maintain standardised cancer reporting data sets. The resultant standardisation of cancer reporting will benefit not only those countries directly involved in the collaboration but also others not in a position to develop their own data sets. We describe the development of a cancer data set by the ICCR expert panel for the reporting of primary ovarian, fallopian tube and peritoneal carcinoma and present the 'required' and 'recommended' elements to be included in the report with an explanatory commentary. This data set encompasses the recent International Federation of Obstetricians and Gynaecologists staging system for these neoplasms and the updated World Health Organisation Classification of Tumours of the Female Reproductive Organs. The data set also addresses issues about site assignment of the primary tumour in high-grade serous carcinomas and proposes a scoring system for the assessment of tumour response to neoadjuvant chemotherapy. The widespread implementation of this data set will facilitate consistent and accurate data collection, comparison of epidemiological and pathological parameters between different populations, facilitate research and hopefully will result in improved patient management.

Cytological scoring and prognosis of poorly differentiated endometrioid adenocarcinoma

OBJECTIVE

Histopathological variation has been demonstrated in grade 3 endometrioid adenocarcinomas. We attempted to evaluate the clinicopathological features of grade 3 tumors by endometrial cytological features using a scoring system.

STUDY DESIGN

Twenty-one endometrial cytological samples were evaluated using 5 cytological features: rates of cluster formation in tumor cells; nuclear pleomorphism; nuclear dimension; size of nucleoli, and chromatin structure and distribution. The relationships between cytological scores and clinicopathological factors or prognosis were investigated.

RESULTS

The median cytological score was 6 (range 4-14); therefore, samples with scores of 4-5 were defined as having low scores, while those with scores of 6-14 were defined as high scores. The accuracy of the cytological diagnosis for grade 3 tumors in the high score group (8/10 patients, 80.0%) was significantly higher than that of the low score group (2/11 patients, 18.2%; p=0.009). Significant relationships between cytological scores and lymph node metastases or positive peritoneal cytology were observed (p=0.03 and 0.035, respectively). The overall survival rate was significantly worse in the high score group (30.0%) than the low score group (88.9%; p=0.02).

CONCLUSIONS

Grade 3 endometrioid adenocarcinomas varied in cytological features; according to the scoring system used, high scores were associated with worse clinicopathological factors and poorer prognosis than low scores.

The evaluation of reliability and contribution of frozen section pathology to staging endometrioid adenocarcinomas

PURPOSE

To evaluate the reliability and accuracy of intraoperative pathological findings, compared to permanent section (PS) and to understand contributions of frozen section (FS) to final staging in patients with endometrioid carcinomas.

METHODS

This is a retrospective analysis of 79 patients undergoing intraoperative FS and with endometrioid adenocarcinomas. Intraoperative pathological findings were compared with final results as to grade, depth of myometrial invasion (MI), cervical involvement, lymphovascular space invasion (LVSI) and stage. We also analyzed whether staging procedures like pelvic or para-aortic lymph node metastasis, peritoneal cytology and extension beyond of uterus were related to FS findings. Staging was based on the FIGO 2009.

RESULTS

FS results were agreement in 89.9 % for grade, 88.6 % for depth of MI, 100 % for cervical invasion, and 92.4 % for LVSI, compared with PS. On FS, 12, 16.6 and 44.4 % of specimens in stages of IA, IB and II became upstaged in final pathology, respectively. Of 79 cases, 5 (6.3 %) were upstaged to IIIC1, and 3 (3.8 %) were upstaged to IIIC2 because of lymph node metastasis. A significant relationship was detected between lymph node metastasis, and FS grades (p = 0.001), LVSI (p = 0.000), cervical invasion (p = 0.006) and MI (p = 0.001).

CONCLUSION

We consider that intraoperative FS is a useful procedure to identify poor prognostic pathological factors. While grading, depth of MI, cervical stromal invasion and LVSI on FS are significant in predicting lymph node metastasis, the existence of cervical stromal invasion and LVSI should be considered more effective parameters in the identification of metastatic endometrial cancer risks.

Reproducibility of histological cell type in high-grade endometrial carcinoma

Subclassification of endometrial carcinoma according to histological type shows variable interobserver agreement. The aim of this study was to assess specifically the interobserver agreement of histological type in high-grade endometrial carcinomas, recorded by gynecological pathologists from five academic centers across Canada. In a secondary aim, the agreement of consensus diagnosis with immunohistochemical marker combinations was assessed including six routine (TP53, CDKN2A (p16), ER, PGR, Ki67, and VIM) and six experimental immunohistochemical markers (PTEN, ARID1A, CTNNB1, IGF2BP3, HNF1B, and TFF3). The paired interobserver agreement ranged from κ 0.50 to 0.63 (median 0.58) and the intraobserver agreement from κ 0.49 to 0.67 (median 0.61). Consensus about histological type based on morphological assessment was reached in 72% of high-grade endometrial carcinomas. A seven-marker immunohistochemical panel differentiated FIGO grade 3 endometrioid from serous carcinoma with a 100% concordance rate compared with the consensus diagnosis. More practically, a three-marker panel including TP53, ER, and CDKN2A (p16) can aid in the differential diagnosis of FIGO grade 3 endometrioid from endometrial serous carcinoma. Our study demonstrates that the inter- and intraobserver reproducibility of histological type based on morphology alone are mostly moderate. Ancillary techniques such as immunohistochemical marker panels are likely needed to improve diagnostic reproducibility of histological types within high-grade endometrial carcinomas.

Is the two-tier ovarian serous carcinoma grading system potentially useful in stratifying uterine serous carcinoma? A large multi-institutional analysis

OBJECTIVE

A subset of uterine serous carcinoma (USC) may have better clinical behavior bringing up the possibility that there may be morphologic features, which would help in their categorization. The aim of this study is to evaluate the potential use of the MD Anderson Cancer Center 2-tier grading system for ovarian carcinoma in USC.

METHODS

Tumors assigned a combined score included in this analysis were 1) low-grade: tumors without marked atypia and 12 mitoses/10 high power field (HPF) and 2) high grade: tumors with severe nuclear atypia and >12 mitoses/10 HPF. Clinicopathologic parameters evaluated included patients' age, tumor size, myometrial invasion (MI), lymphovascular invasion (LVI), lymph node (LN), FIGO stage, and patient outcome.

RESULTS

140 patients with USC were included, 30 low grade uterine serous carcinoma (LGUSC) and 110 high grade uterine serous carcinoma (HGUSC). Of all parameters only 2 (MI and stage IA) reached statistical significance. 67% of LGUSC cases showed myometrial invasion versus 93.6% HGUSC cases (p = 0.003). A higher percentage of LGUSC (63.3%) versus HGUSC (32.7%) were in stage IA (p = 0.01). However, by multivariate analysis including age, LVI, stage and tumor grade only stage was an independent prognostic factor.

CONCLUSION

The presence of atypia and mitosis across a uterine serous carcinoma is notoriously variable in magnitude and extent, potentially making evaluation of these features difficult and subsequent grading subjective. Our findings thus show that actual prognostic utility of application of MDACC two-tier grading system to uterine serous carcinoma may not be applicable.

Poor interobserver reproducibility in the diagnosis of high-grade endometrial carcinoma

Patients with high-grade subtypes of endometrial carcinoma (grade 3 endometrioid, serous, clear cell, or carcinosarcoma) have a relatively poor prognosis. The specific subtype may be used to guide patient management, but there is little information on the reproducibility of subtype diagnosis in cases of high-grade endometrial carcinoma. Fifty-six cases diagnosed as a high-grade subtype of endometrial carcinoma were identified from the pathology archives of Vancouver General Hospital. All slides for each case were reviewed independently by 3 pathologists, who diagnosed the specific tumor subtype(s) and assigned the percentage of each subtype for mixed tumors. Agreement between observers was categorized as follows: major disagreement: (A) no consensus for low-grade endometrioid versus high-grade carcinoma (any subtype), or (B) no consensus with respect to the predominant high-grade subtype present; minor disagreement: consensus was reached about the cell type of the predominant component of a mixed tumor, but there was disagreement about the subtype of the minor component. A tissue microarray was constructed from these cases and immunostained for p16, ER, PR, PTEN, and p53. In 35 of 56 (62.5%) cases, there was agreement between all 3 reviewers regarding the subtype diagnosis of the exclusive (in pure tumors) or predominant (in mixed tumors) high-grade component. Of these cases, there was a minor disagreement (ie, disagreement about the minor high-grade component subtype in a mixed tumor) in 4 cases (4/56, 7.1%). In 20 of 56 (35.8%) cases there was a major disagreement; in 17 (30.4%) of these cases there was no consensus about the major subtype diagnosis, whereas in 3 (5.4%) cases there was disagreement about whether a component of high-grade endometrial carcinoma was present. In the final case, all 3 reviewers diagnosed the case as low-grade endometrioid carcinoma, disagreeing with the original diagnosis of high-grade carcinoma. The most frequent areas of disagreement were serous versus clear cell (7 cases) and serous versus grade 3 endometrioid (6 cases). Immunostaining results using the 5-marker immunopanel were then used to adjudicate in the 6 cases in which there was disagreement between reviewers with respect to serous versus endometrioid carcinoma, and these supported a diagnosis of serous carcinoma in 4 of 6 cases and endometrioid carcinoma in 2 of 6 cases. Pairwise comparison between the reviewers for the 20 cases classified as showing major disagreement was as follows: reviewer 1 and reviewer 2 agreed in 5/20 cases, reviewer 1 and reviewer 3 agreed in 7/20 cases, and reviewer 2 and reviewer 3 agreed in 8/20 cases, indicating that disagreements were not because of a single reviewer holding outlier opinions. Diagnostic consensus among 3 reviewers about the exclusive or major subtype of high-grade endometrial carcinoma was reached in only 35/56 (62.5%) cases, and in 4 of these cases there was disagreement about the minor component present. This poor reproducibility did not reflect systematic bias on the part of any 1 reviewer. There is a need for molecular tools to aid in the accurate and reproducible diagnosis of high-grade endometrial carcinoma subtype.

Proliferation indices of phosphohistone H3 and Ki67: strong prognostic markers in a consecutive cohort with stage I/II melanoma

Cellular proliferation is correlated with the progression of melanoma. Accordingly, the proliferation index of H&E-stained thin melanomas was recently included in the staging system of the American Joint Committee on Cancer. Yet, the immunohistochemical markers of proliferation phosphohistone H3 and Ki67 may improve such indices. To accurately quantify these markers, they should be combined with a melanocytic marker, for example, MART1 in an immunohistochemical double stain; also enabling automated quantification by image analysis. The aim of the study was to compare the prognostic impact of phosphohistone H3/MART1, Ki67/MART1, and H&E stains in primary cutaneous melanoma, and to determine the difference between indices established in hot spots and the global tumor areas. The study included 153 consecutive stage I/II melanoma-patients. The follow-up time was 8-14 years for event-free melanoma. Recurrent disease occurred in 43 patients; 37 died of melanoma. Both events occurred in only three thin melanomas. Their paraffin-embedded tissue was stained for phosphohistone H3/MART1, Ki67/MART1, and with H&E. And proliferation indices were established in 1-mm(2) hot spots and in the global tumor areas. In multivariate Cox analyses, only hot spot indices of phosphohistone H3/MART1 and Ki67/MART1 were independent prognostic markers. Phosphohistone H3/MART1 tended to be better than Ki67/MART1 with adjusted hazard ratios of 3.66 (95% CI, 1.40-9.55; P=0.008) for progression-free survival and 3.42 (95% CI, 1.29-9.04; P=0.013) for melanoma-specific death. In all stains, prognostic performance was substantially improved by using hot spots instead of the global tumor areas. In conclusion, phosphohistone H3/MART1 and Ki67/MART1 were superior to H&E stains, and hot spots superior to the global tumor areas. Given the potential for automated analysis, these double stains seem to be robust alternatives to conventional mitotic detection by H&E in stage I/II melanomas in general. This was particularly true for thick melanomas whereas no specific analyses for thin melanomas only could be performed.

Clinicopathologic analysis of matched primary and recurrent endometrial carcinoma

It is unknown whether the type and grade of a primary endometrial carcinoma is reliably maintained in recurrence. All matched primary and recurrent endometrial carcinomas diagnosed from 2000 to 2010 at our institution were identified; 34 cases had available slides. Histologic classification was performed using modifications to the World Health Organization criteria. Immunohistochemical analysis for p53, p16, progesterone receptor (PR), and DNA mismatch-repair proteins (MMR) (MLH1, MSH2, MSH6, and PMS2) was performed. Endometrioid carcinoma recurrences were mostly local, whereas serous carcinoma recurrences were mostly peritoneal. Compared with endometrioid carcinoma patients, serous carcinoma patients were older, presented at high stage, and had shorter survival. Serous carcinomas were the most common recurrent endometrial carcinoma (18/34 cases). Overall, 21 cases (62%) displayed similar morphology when comparing primary and recurrent carcinomas, whereas 13 displayed discordant morphology. Seven of 13 endometrioid carcinomas (54%) had a morphologically discordant recurrence, compared with 3 of 14 serous carcinomas (21%), 1 of 4 morphologically ambiguous carcinomas (25%), and both mixed epithelial carcinomas. Serous and morphologically ambiguous carcinomas therefore demonstrated relative morphologic fidelity compared with endometrioid carcinomas. Four morphologically discordant cases demonstrated either pure clear cell carcinoma or clear cell features at recurrence. Seven of 23 matched pairs displayed discordant PR results, with 5 cases, including both endometrioid and serous carcinomas, showing diminished PR expression at recurrence. p53, p16, and DNA MMR staining results were generally concordant when evaluating matched pairs, with only occasional exceptions. Sixty-four percent of all pure endometrioid carcinomas and mixed epithelial carcinomas with an endometrioid component showed loss of expression of MLH1 and/or PMS2; no serous carcinoma demonstrated this abnormality. Clinical and immunohistochemical data supported the use of modifications to the World Health Organization diagnostic criteria. More importantly, the data suggest that when confronted with recurrent endometrial carcinoma, particularly a serous carcinoma, it is reasonable to base therapeutic decisions on the type of the primary tumor, especially if sampling or excising the recurrent tumor is problematic. However, in light of the PR results, sampling a recurrent endometrioid carcinoma may be worthwhile if hormonal therapy is planned. Recurrent endometrioid carcinoma may be enriched for tumors with DNA MMR abnormalities.

Automated Quantification of MART1-Verified Ki67 Indices by Digital Image Analysis in Melanocytic Lesions

Context.—The proliferation marker Ki67 is an important diagnostic and prognostic aid in surgical pathology. However, manual quantification in a counting frame to accurately establish the proliferation rate (Ki67 index) is cumbersome and time-consuming. Instead, digital image analysis of Ki67/MART1 double stains may provide fast and novel index computations for entire tumor sections.

Objectives.—To design and compare image analysis protocols that compute Ki67 indices of Ki67/MART1 double stains, to compare automated indices with previously published manual indices, and to compare the total number of proliferating cells (mimicking a Ki67 single stain) with the number of MART1-verified proliferating cells.

Design.—Whole slide images were captured from 48 melanomas and 77 nevi stained with an immunohistochemical cocktail against Ki67 and MART1. Ki67 indices were determined by digital image analysis and different equations based on number or area.

Results.—The differences between mean indices of melanomas and nevi were significant (P &lt; .001) in all index computations. Number-based image analysis of lesions with more than 250 melanocytic cells misclassified 1 of 42 melanomas and 4 of 53 nevi, numbers comparable with manual counting. Automated indices were significantly higher than manual indices, as were indices of mimicked Ki67 single stains compared with MART1-verified Ki67 indices (P &lt; .001).

Conclusions.—Ki67 indices established by digital image analysis of Ki67/MART1 double stains demonstrated excellent abilities to discriminate melanomas from nevi with diagnostic performances equal to manually performed indices. Testing different definitions of the automated MART1-verified Ki67 index, no single definition stood out; thus, a variety of definitions may be used.

Strategies for distinguishing low-grade endometrioid and serous carcinomas of endometrium

Distinction between endometrioid and serous carcinomas of the endometrium has important prognostic and therapeutic implications. Misdiagnosing a serous carcinoma as endometrioid can have significant consequences for the patient and pathologist. Although many cases are straightforward and easy to classify, there are occasional problematic cases. This review focuses on strategies that help differentiate between low-grade endometrioid carcinoma and serous carcinoma of the endometrium. We will discuss clinical, morphologic, and immunohistochemical differences between the 2 entities and provide practical tips for practicing pathologists when confronted with this differential diagnosis.

Endometrial carcinomas: a review emphasizing overlapping and distinctive morphological and immunohistochemical features

This review focuses on the most common diagnostic pitfalls and helpful morphologic and immunohistochemical markers in the differential diagnosis between the different subtypes of endometrial carcinomas, including: (1) endometrioid versus serous glandular carcinoma, (2) papillary endometrioid (not otherwise specified, villoglandular and nonvillous variants) versus serous carcinoma, (3) endometrioid carcinoma with spindle cells, hyalinization, and heterologous components versus malignant mixed müllerian tumor, (4) high-grade endometrioid versus serous carcinoma, (5) high-grade endometrioid carcinoma versus dedifferentiated or undifferentiated carcinoma, (6) endometrioid carcinoma with clear cells versus clear cell carcinoma, (7) clear cell versus serous carcinoma, (8) undifferentiated versus neuroendocrine carcinoma, (9) carcinoma of mixed cell types versus carcinoma with ambiguous features or variant morphology, (10) Lynch syndrome-related endometrial carcinomas, (11) high-grade or undifferentiated carcinoma versus nonepithelial uterine tumors. As carcinomas in the endometrium are not always primary, this review also discusses the differential diagnosis between endometrial carcinomas and other gynecological malignancies such as endocervical (glandular) and ovarian/peritoneal serous carcinoma, as well as with extra-gynecologic metastases (mainly breast and colon).

Immunohistochemical double stains against Ki67/MART1 and HMB45/MITF: promising diagnostic tools in melanocytic lesions

Distinction between benign and malignant melanocytic lesions may be difficult by today's methods, even for highly skilled dermatopathologists, emphasizing the need for improved diagnostic tools. We have studied the discriminative abilities of immunohistochemical (IHC) double stains using the IHC markers Ki67 combined with MART1, and HMB45 combined with MITF. Paraffin-embedded tissue sections from 50 melanomas and 78 benign nevi were stained using a simple simultaneous IHC double staining technique. Both simple semiquantitative estimates of the immunopositivity in the deepest third of the lesions and full-scale quantitative measurements of the Ki67 and HMB45 indices were performed, and scores for melanomas and nevi were compared. The differences between melanomas and nevi were significant (P < 0.0001) using either analysis or stain. The misclassification rates for melanomas and nevi were generally lower for Ki67/MART1 stains than for HMB45/MITF stains. In the simple semiquantitative Ki67/MART1 analysis, the misclassification rates were 6% (2%-17%) for melanomas and 12% (6%-21%) for nevi. In full-scale quantitative analysis the corresponding rates were 4% (1%-14%) and 8% (4%-16%), and by combining Ki67 and HMB45 indices, the misclassification rates were 0% (0%-7%) for melanomas and 13% (7%-22%) for nevi. We conclude that both semiscale and fullscale quantitative analyses of Ki67/MART1 stains are valuable diagnostic tools to distinguish melanomas and nevi with a large degree of certainty. The HMB45/MITF stains may serve as adjuncts to predict malignancy and the diagnostic potential of combining the HMB45 and Ki67 indices are promising. The IHC double stains may potentially reduce misinterpretations of melanomas in histopathology.

Prognosis and Reproducibility of New and Existing Binary Grading Systems for Endometrial Carcinoma Compared to FIGO Grading in Hysterectomy Specimens

Background:

The current International Federation of Gynecology and Obstetrics (FIGO) grade in endometrial carcinomas requires the evaluation of histologic features with proven prognostic value but with questionable reproducibility. This study tests the prognostic power and reproducibility of a new binary grading system.

Study Design:

Specimens from 254 hysterectomies were graded according to the new 3- and 2-tiered FIGO grading systems described by Alkushi et al. The selected morphologic parameters for the new grading system included the presence of predominant solid or papillary architecture pattern, severe nuclear atypia, tumor necrosis, and vascular invasion. The Cox proportional hazards and κ statistics were used for comparisons.

Results:

On multivariate analysis, and looking at all tumor cell types, the 4 tested grading systems were independent predictors of survival, with the 3-tiered FIGO grading system being the most predictive (P = 0.005). In the subset of endometrioid tumors, the 3- and 2-tiered FIGO grading systems and the new grading system retained their statistical significance as predictors of survival (P = 0.004, P = 0.03, and P = 0.007, respectively), whereas the grading system of Alkushi et al did not (P = 0.1). In nonendometrioid tumors, the new grading system proved to be the best predictor of survival, reaching near statistical significance (P = 0.06). The new grading system had acceptable intraobserver and interobserver reproducibility assessment (κ = 0.87 and κ = 0.45, respectively).

Conclusion:

The 3-tiered FIGO grading system retained its superior prognostic power. However, available binary grading systems remain an attractive option by being highly reproducible and by eliminating the clinical ambiguity of intermediate grades of disease.

High-Grade Endometrial Carcinomas

High-grade endometrial carcinomas are a heterogeneous group of clinically aggressive tumors. They include FIGO grade 3 endometrioid carcinoma, serous carcinoma, clear cell carcinoma, undifferentiated carcinoma, and malignant mixed Müllerian tumor (MMMT). Epidemiologic, genetic, biologic prognostic and morphologic differences between these entities are striking in prototypic cases, yet substantial overlap exists and diagnostic criteria and therapeutic approaches that account for the group's diversity are currently insufficient. FIGO grade 3 endometrioid carcinoma demonstrates solid, trabecular or nested growth and may resemble poorly differentiated squamous cell carcinoma. Endometrioid glandular differentiation is usually focally present. Serous carcinoma usually displays papillary architecture but glandular and solid patterns may predominate. Tumor cells typically display diffuse and severe atypia. Clear cell carcinoma should be diagnosed by recognizing characteristic papillary or tubulocystic architecture with cuboidal tumor cells showing atypical but uniform nuclei. Cells with clear cytoplasm are frequently but not always present. On the other hand, clear cells may be encountered in endometrioid and serous carcinomas. Immunohistochemical stains for p53, p16, ER, PR, mib-1, hepatocyte nuclear factor 1β and pan-cytokeratin can be helpful in classifying these high-grade carcinomas. They should be used in concert with thorough morphologic examination, as part of a rational panel of markers and only in specific circumstances. Although these tumors may appear clinically and even morphologically similar, demographic and epidemiologic features as well as patterns of spread and treatment modalities differ.

Atypical Endometrial Hyperplasia and Well Differentiated Endometrioid Adenocarcinoma of the Uterine Corpus

The distinction between atypical endometrial hyperplasia and well differentiated adenocarcinoma of the endometrium is one of the more difficult differential diagnoses in gynecologic pathology. Different pathologists apply different histologic criteria, often with different individual thresholds for atypical endometrial hyperplasia and grade 1 adenocarcinoma. While some classifications are based on a series of molecular genetic alterations (which may or may not translate into biologically or clinically relevant risk lesions), almost all current diagnostic criteria use a series of histologic features - usually a combination of architecture and cytology - for diagnosing atypical hyperplasia and adenocarcinoma. This article presents evidence-based histologic criteria for atypical endometrial hyperplasia and low grade endometrial carcinoma (both FIGO grade 1 and 2) with emphasis on common and not so common histologic mimics. Grade 3 endometrioid carcinoma is discussed in the Oliva and Soslow article in this publication.