Accurate Distinction of Ovarian Clear Cell From Endometrioid Carcinoma Requires Integration of Phenotype, Immunohistochemical Predictions, and Genotype: Implications for Lynch Syndrome Screening.

Ovarian clear cell carcinoma (OCCC) and ovarian endometrioid carcinoma (OEC) are both associated with endometriosis but differ in histologic phenotype, biomarker profile, and survival. Our objectives were to refine immunohistochemical (IHC) panels that help distinguish the histotypes and reassess the prevalence of mismatch repair deficiency (MMRd) in immunohistochemically confirmed OCCC. We selected 8 candidate IHC markers to develop first-line and second-line panels in a training set of 344 OCCC/OEC cases. Interobserver reproducibility of histotype diagnosis was assessed in an independent testing cohort of 100 OCC/OEC initially without and subsequently with IHC. The prevalence of MMRd was evaluated using the testing cohort and an expansion set of 844 ovarian carcinomas. The 2 prototypical combinations (OCCC: Napsin A+/HNF1B diffusely+/PR-; OEC: Napsin A-/HNF1B nondiffuse/PR+) occurred in 75% of cases and were 100% specific. A second-line panel (ELAPOR1, AMACR, CDX2) predicted the remaining cases with 83% accuracy. Integration of IHC improved interobserver reproducibility (κ=0.778 vs. 0.882, P<0.0001). The prevalence of MMRd was highest in OEC (11.5%, 44/383), lower in OCCC (1.7%, 5/297), and high-grade serous carcinomas (0.7%, 5/699), and absent in mucinous (0/126) and low-grade serous carcinomas (0/50). All 5 MMRd OCCC were probable Lynch syndrome cases with prototypical IHC profile but ambiguous morphologic features: 3/5 with microcystic architecture and 2/5 with intratumoral stromal inflammation. Integration of first-line and second-line IHC panels increases diagnostic precision and enhances prognostication and triaging for predisposing/predictive molecular biomarker testing. Our data support universal Lynch syndrome screening in all patients with OEC when the diagnosis of other histotypes has been vigorously excluded.

p16 is superior to Stathmin-1 and HSP27 in identifying cervical dysplasia.

BACKGROUND: The aim of this study was to determine how Stathmin-1 and Heat Shock Protein 27 (HSP27) can be used as adjunctive biomarkers to differentiate high-grade dysplasia from benign/reactive lesions in cervical tissues. In addition, we aimed to see if any of these markers can differentiate endometrial from endocervical adenocarcinomas. METHODS: Fifty cases including benign cervical tissue, low-grade squamous intraepithelial lesion (LSIL), high-grade squamous intraepithelial lesion (HSIL), adenocarcinoma in situ of the endocervix, invasive endocervical adenocarcinoma, and endometrial adenocarcinoma were selected. Stathmin-1 and HSP27 immunohistochemistry (IHC) were performed for each case and the results were compared to the previously available p16 IHC stains. RESULTS: p16 stained positively in 100% of HSIL, endocervical adenocarcinoma in situ, and invasive endocervical cases. Stathmin-1 stained positively in 43% of HSIL and 90% of endocervical adenocarcinoma in situ and all invasive endocervical cases. Stathmin-1 and p16 were negative in all benign cervical samples. Stathmin-1, HSP27, and p16 stained 100% of LSIL cases. HSP27 stained indiscriminately, including 100% of benign cervical tissue. 87% of the endometrial adenocarcinomas stained positively for p16, Stathmin-1, and HSP27. CONCLUSION: p16 remains superior to both Stathmin-1 and HSP27 in differentiating dysplasia from benign, reactive changes of the cervix.

Clinicopathological features and prognostic significance of CTNNB1 mutation in low-grade, early-stage endometrial endometrioid carcinoma.

Low-grade and early-stage endometrioid endometrial carcinomas (EECs) have an overall good prognosis but biomarkers identifying patients at risk of relapse are still lacking. Recently, CTNNB1 exon 3 mutation has been identified as a potential risk factor of recurrence in these patients. We evaluate the prognostic value of CTNNB1 mutation in a single-centre cohort of 218 low-grade, early-stage EECs, and the correlation with beta-catenin and LEF1 immunohistochemistry as candidate surrogate markers. CTNNB1 exon 3 hotspot mutations were evaluated by Sanger sequencing. Immunohistochemical staining of mismatch repair proteins (MLH1, PMS2, MSH2, and MSH6), p53, beta-catenin, and LEF1 was performed in representative tissue microarrays. Tumours were also reviewed for mucinous and squamous differentiation, and MELF pattern. Nineteen (8.7%) tumours harboured a mutation in CTNNB1 exon 3. Nuclear beta-catenin and LEF1 were significantly associated with CTNNB1 mutation, showing nuclear beta-catenin a better specificity and positive predictive value for CTNNB1 mutation. Tumours with CTNNB1 exon 3 mutation were associated with reduced disease-free survival (p = 0.010), but no impact on overall survival was found (p = 0.807). The risk of relapse in tumours with CTNNB1 exon 3 mutation was independent of FIGO stage, tumour grade, mismatch repair protein expression, or the presence of lymphovascular space invasion. CTNNB1 exon 3 mutation has a negative impact on disease-free survival in low-grade, early-stage EECs. Nuclear beta-catenin shows a higher positive predictive value than LEF1 for CTNNB1 exon 3 mutation in these tumours.

BRG1, INI1, and ARID1B Deficiency in Endometrial Carcinoma: A Clinicopathologic and Immunohistochemical Analysis of a Large Series From a Single Institution.

Switch/sucrose nonfermenting complex subunits, such as BRG1, INI1, and ARID1B, are inactivated in a subset of endometrial undifferentiated carcinoma and dedifferentiated carcinoma (DC). Limited information is currently available on their prevalence in other subtypes or the nosological status of endometrial carcinoma with their deficiencies. This study immunohistochemically examined the expression status of BRG1, INI1, and ARID1B using 570 archived cases of endometrial carcinoma and carcinosarcoma resected at a single institution. We identified 1 BRG1-deficient undifferentiated carcinoma, 8 BRG1/INI1/ARID1B-deficient DC, and 3 BRG1-deficient clear-cell carcinomas. None of the cases of endometrioid and serous carcinomas or carcinosarcoma showed deficiencies of these subunits. We then compared 8 BRG1/INI1/ARID1B-deficient DC with 6 BRG1/INI1/ARID1B-intact DC and 28 carcinosarcomas, the latter of which was often confused with DC. Histologically, BRG1/INI1/ARID1B-intact and BRG1/INI1/ARID1B-deficient DC shared a monotonous solid appearance with rhabdoid and epithelioid cells and a myxoid stroma; however, abrupt keratinization and cell spindling was absent in BRG1/INI1/ARID1B-deficient tumors. The median overall survival of patients with BRG1/INI1/ARID1B-deficient DC was 3.8 months, which was worse than those with BRG1/INI1/ARID1B-intact DC (P=0.008) and with carcinosarcoma (P=0.004). BRG1/INI1/ARID1B-deficient DC may be a separate entity with an aggressive behavior to be distinguished from BRG1/INI1/ARID1B-intact DC and carcinosarcoma. Regarding clear-cell carcinoma (n=12), BRG1 deficiency appeared to be mutually exclusive with abnormal ARID1A, BRM, and p53 expression. Further studies are needed to clarify whether BRG1 deficiency plays a role in the pathogenesis of clear-cell carcinoma.

Molecular Profiles of Mixed Endometrial Carcinoma.

Mixed endometrial carcinomas are defined as a combination of 2 or more distinct histologic subtypes, one of which must be a type II tumor comprising at least 5% of the tumor volume. The oncogenesis of these tumors remains unclear, particularly in light of the increasingly appreciated morphologic overlap among subtypes, as well as evolving molecular data. We evaluated 8 cases of mixed endometrial carcinoma, including 4 endometrioid (EC)/serous (SC), 1 SC/clear cell (CC), and 3 EC/CC cases, to study the underlying molecular features and oncogenic mechanisms at play. Each component was analyzed by a targeted next-generation sequencing assay. All tumors shared mutations in both components. In 6 cases, one component showed additional mutations. Two EC/SC cases showed shared mutations and mutations unique to each component. When present, unique mutations were typically seen in the SC component, including variants in POLE and TP53, as well as potentially targetable genes DDR2, MAP2K1, and CCNE1. In EC/SC tumors, ERBB2 abnormalities were seen in 2 cases. EC/CC cases showed FGFR2 activating mutations in the EC component only. No fusion drivers were identified. Our data suggest that the majority of these tumors begin as a single clone and diverge along 2 pathways: (1) tumor progression, with one component showing additional mutations, and (2) tumor divergence, in which tumor components have both shared mutations and mutations unique to each component. In addition, the findings suggest a component of morphologic mimicry in these tumors. Our findings are clinically relevant since targetable mutations may be present in only one component of mixed tumors.

Proteomic analysis in endometrial cancer and endometrial hyperplasia tissues by 2D-DIGE technique.

OBJECTIVE: To compare the protein expression of complex atypical endometrial hyperplasia, endometrial carcinoma and healthy endometrial tissues, and by this way, to identify proteins that can be used for diagnosis, prognosis and therapeutic targets. METHODS: Histopathological examination of the D&C material had reported "benign endometrial changes", "complex atypical endometrial hyperplasia" and "endometrioid adenocarcinoma" and 30 patients ,who underwent surgery with these diagnosis, were studied. Protein profiles of the study groups were detected using 2D-DIGE technique and compared to the control group. Protein spots which showing different expression, were defined by MALDI TOF/TOF-MS method. RESULTS: In the present study, significant elevations were observed in the levels of K2C8, UAP56, ENOA, ACTB, GRP78, GSTP1, PSME1, CALR, PPIA, PDIA3 and IDHc proteins when comparisons were made among the cancer cases and the healthy and complex atypical hyperplasia cases. We determined that the induction of CALR activity may be a factor that progresses apoptosis, thus, may be a hope for postoperative new chemotherapy treatment methods. Moreover, when the expressions of the CAH1 and PPIB proteins are compared to complex atypical hyperplasia and endometrial adenocarcinoma stages, we determined that the CAH1 and PPIB levels increased in more advanced stages. Among these indicators, the proteins that had the closest relation to advanced stage cancer were determined as K2C8, UAP56 and GRP78. CONCLUSION: We think that it would be useful to determine the diagnosis, prediction of prognosis and identifying therapeutic targets of the highlighted proteins of our study that are K2C8, UAP56, GRP78 and CALR in endometrial cancer.

Endometrioid Tubal Intraepithelial Neoplasia (E-TIN) of the Fallopian Tube: A Case Series.

Although serous tubal intraepithelial carcinoma has been well described in the distal fallopian tube as precancers of pelvic high-grade serous carcinoma, endometrioid precancers have drawn less attention. Recently, endometrioid precursor lesions have been identified and reported to have a specific immunophenotype (PAX2-, ALDH1+, diffuse nuclear beta-catenin), as well as an association with both uterine and ovarian endometrioid carcinomas. These have been referred to as endometrioid (or type II) secretory cell outgrowths. A subset of endometrioid secretory cell outgrowths show architectural complexity resembling hyperplasia of the endometrium and have been referred to as endometrioid tubal intraepithelial neoplasia. We report 4 cases of endometrioid tubal intraepithelial neoplasia with clinical correlation and morphologic differential diagnosis.

Role of epithelial-mesenchymal transition factors in the histogenesis of uterine carcinomas.

Several subtypes of high-grade endometrial carcinomas (ECs) contain an undifferentiated component of non-epithelial morphology, including undifferentiated and dedifferentiated carcinomas and carcinosarcomas (CSs). The mechanism by which an EC undergoes dedifferentiation has been the subject of much debate. The epithelial-mesenchymal transition (EMT) is one of the mechanisms implicated in the transdifferentiation of high-grade carcinomas. To improve our understanding of the role of EMT in these tumors, we studied a series of 89 carcinomas including 14 undifferentiated/dedifferentiated endometrial carcinomas (UECs/DECs), 49 CSs (21 endometrial, 29 tubo-ovarian and peritoneal), 17 endometrioid carcinomas (grade 1-3), and 9 high-grade serous carcinomas of the uterus, using a panel of antibodies targeting known epithelial markers (Pan-Keratin AE1/AE3 and E-cadherin), mesenchymal markers (N-cadherin), EMT transcription factors (TFs) (ZEB1, ZEB2, TWIST1), PAX8, estrogen receptors (ER), progesterone receptors (PR), and the p53 protein. At least one of the three EMT markers (more frequently ZEB1) was positive in the sarcomatous component of 98% (n = 48/49) of CSs and 98% (n = 13/14) of the undifferentiated component of UEC/DEC. In addition, 86% of sarcomatous areas of CSs and 79% of the undifferentiated component of UEC/DEC expressed all three EMT-TFs. The expression of these markers was associated with the loss of or reduction in epithelial markers (Pan-keratin, E-cadherin), PAX8, and hormone receptors. In contrast, none of the endometrioid and serous endometrial carcinomas expressed ZEB1, while 6% and 36% of endometrioid and 11% and 25% of serous carcinomas focally expressed ZEB2 and TWIST1, respectively. Although morphologically different, EMT appears to be implicated in the dedifferentiation in both CSs and UEC/DEC. Indeed, we speculate that the occurrence of EMT in a well differentiated endometrioid carcinoma may consecutively lead to a dedifferentiated and undifferentiated carcinoma, while in a type II carcinoma, it may result in a CS.

Expression of microRNA-145, OCT4, and SOX2 in double primary endometrioid endometrial and ovarian carcinomas.

Double primary endometrioid endometrial and ovarian carcinomas (DPEEOCs) are the most common multiple gynecological carcinomas. In recent years, gene sequential comparison analysis has strongly supported the opinion that sporadic double endometrioid endometrial and ovarian cancers (DEEOCs) are clonally related in both primary and metastatic tumors. In order to find more clonal evidence for DPEEOC, we investigated cancer stem cells (CSCs). SOX2 and OCT4 are two common factors in CSCs. MicroRNA (miRNA)-145, a small non-coding RNA, has effects in regulating gene expression and tumorigenesis in CSCs. The aim of this study was to assess the involvements of SOX2, OCT4, and miRNA-145 in the tumorigenesis of DPEEOCs. In our study, twenty DPEEOC patients were chosen. Metastatic DEEOCs and normal endometrial and ovarian tissues were also included. The expression of miRNA-145 was detected by real-time quantitative PCR. Immunohistochemical staining was used to measure the expression of OCT4 and SOX2. The results showed that miRNA-145 expression was lower in DPEEOC endometrial tissues and higher in DPEEOC ovarian tissues compared to the corresponding normal tissues. Both SOX2 and OCT4 were over-expressed in cancer tissues compared with that in normal tissues. MiRNA-145, SOX2, and OCT4 were expressed at similar levels in two cancer sites of a given DPEEOC or metastatic DEEOC sample. Besides, metastatic DEEOC sections expressed a higher level of SOX2 and OCT4 compared to the corresponding DPEEOC tissues. Together, these results support the clonality of DPEEOCs. Moreover, SOX2 and OCT4 may have some implication in DPEEOC and metastatic DEEOC diagnosis.

High-grade Endometrioid Carcinoma of the Ovary: A Clinicopathologic Study of 30 Cases.

Although infrequently encountered, the diagnosis of ovarian high-grade endometrioid carcinoma remains a diagnostic challenge with potential consequences for targeted therapies and genetic counselling. We studied the clinical, morphologic, and immunohistochemical features of ovarian high-grade endometrioid carcinomas and their diagnostic reproducibility compared with tuboovarian high-grade serous carcinomas. Thirty cases confirmed as International Federation of Gynecology and Obstetrics grade 3 endometrioid carcinomas were identified from 182 ovarian endometrioid carcinomas diagnosed in Alberta, Canada, between 1978 and 2010, from the population-based Alberta Ovarian Tumor Types cohort. Cases of lower grade endometrioid and high-grade serous carcinoma served for comparison. Ten immunohistochemical markers were assessed on tissue microarrays. Clinical data were abstracted and survival analyses performed using Cox regression. Interobserver reproducibility for histologic type was assessed using 1 representative hematoxylin and eosin-stained slide from 25 randomly selected grade 3 endometrioid carcinomas and 25 high-grade serous carcinomas. Histotype was independently assigned by 5 pathologists initially blinded to immunohistochemical WT1/p53 status, with subsequent reassessment unblinded to WT1/p53 status. Patients diagnosed with grade 3 endometrioid carcinoma had a significantly longer survival compared with high-grade serous carcinoma in univariate analysis (hazard ratio [HR]=0.34, 95% confidence interval [CI]=0.16-0.67, P=0.0012) but not after adjusting for age, stage, treatment center, and residual tumor (HR=1.01, 95% CI=0.43-2.16, P=0.98). Grade 3 endometrioid carcinoma cases (N=30) were identical to grade 2 endometrioid carcinoma cases (N=23) with respect to survival in univariate analysis (HR=1.07, 95% CI=0.39-3.21, P=0.89) and immunohistochemical profile. Using histomorphology alone, interobserver agreement for the diagnosis of grade 3 endometrioid or high-grade serous carcinoma was 69%, which significantly increased (P<0.0001) to 96% agreement with the knowledge of WT1/p53 status. Our data support the diagnostic value of WT1/p53 status in differentiating between grade 3 endometrioid carcinoma and high-grade serous carcinoma. However, grade 3 and grade 2 endometrioid carcinomas showed no differences in immunophenotype or clinical parameters, suggesting that they could be combined into a single group.

Panel of Villin, Pro-Ex-C, Estrogen Receptor and Progesterone Receptor Expressions Could Help in Differentiation Between Endocervical and Endometrioid Adenocarcinoma.

OBJECTIVE: Endocervical and endometrioid adenocarcinoma have marked overlapping features and the differentiation between them is important for their accurate management. Villin is an actin-binding protein which has an important role in the maintenance of microvilli in epithelial cells and epithelial cell-specific anti-apoptotic protein processes. Pro-Ex-C is a marker for higher-risk human papilloma virus (HPV) which targets the cell cycle proteins causing their overexpression. The aim of the study was to clarify the diagnostic and predictive role of villin, Pro-Ex-C, estrogen receptor (ER) and progesterone receptor (PR) expression in endocervical and endometrioid adenocarcinoma. MATERIAL AND METHOD: We evaluated villin, Pro-Ex-C, ER and PR expressions in 15 cases of endocervical adenocarcinoma and 30 cases of endometrioid adenocarcinoma. We analyzed the diagnostic and predictive role of that panel in both carcinoma subtypes. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated. RESULTS: Positive villin and Pro-Ex-C expressions were positively correlated with the presence and pattern of cervical stromal invasion (p < 0.05). ER was positive in all cases of endometrioid adenocarcinoma. PR was detected in most cases of endometrioid adenocarcinoma. The differences of villin, Pro-Ex-C, ER and PR expression in endocervical and endometrioid adenocarcinoma was statistically significant (p < 0.05). This methodology for distinguishing endocervical and endometrioid adenocarcinoma had a sensitivity of 100%, a specificity of 100% and a significant prognostic and predictive role. CONCLUSION: In conclusion, villin, Pro-Ex-C, ER and PR expressions have diagnostic and predictive roles in endocervical and endometrioid adenocarcinoma.

[Morphologic features of fallopian tubal epithelium in pelvic high-grade serous carcinoma].

Objective: To study the pathologic features of fallopian tubal epithelium in patients with pelvic high-grade serous carcinoma (HGSC), to investigate its role in pelvic serous carcinogenesis and to reclassify the primary site of HGSC based on recently proposed criteria. Methods: The fallopian tubes in 58 cases of pelvic HGSC (54 cases of ovarian primary, 3 cases of tubal primary, 1 case of peritoneum) and 25 cases of pelvic non-HGSC (5 cases of ovarian low-grade serous cancer, 9 cases of endometrioid cancer, and 11 cases of clear cell ovary carcinoma) were collected from June 2015 to December 2016, and serially examined under light microscope (SEE-FIM protocol). Immunostaining for p53 and Ki-67 was performed to evaluate the presence of p53 signature, serous tubal intraepithelial lesion (STIL), serous tubal intraepithelial carcinoma (STIC) and invasive carcinoma in these fallopian tubes. Meanwhile, primary site of HGSC based on the recently proposed diagnostic criteria were also reclassified. Results: Among the study group, the frequencies of p53 signature, STIL, STIC and invasive HGSC were 27.6% (16/58), 43.1% (25/58), 36.2% (21/58) and 67.2% (39/58), respectively, while in control group, the proportions were 24.0% (6/25), 0, 0 and 8.0% (2/25), respectively. The continuum of epithelial changes in the process of serous neoplasia including p53 signature, STIL, STIC and invasive carcinoma was identified in 8 cases of pelvic HGSC. The proportions of STIL, STIC and invasive carcinomas in HGSC group were higher than that in non-HGSC group (P<0.01). About 80.0% (20/25) of STIL and 85.7% (18/21) of STIC were present unilaterally. Diagnostically, the study group contained the 17 cases of ovarian HGSC, 40 cases of tubal HGSC, and 1 case of peritoneal HGSC after reclassification of the cancer primary. Conclusions: Continuous changes of tubal epithelium including p53 signature, STIL, STIC and invasive carcinomas are identified in patients with HGSC, supporting the current understanding that the fallopian tube is likely the cellular source of the majority HGSC. STIL and STIC may be specific to pelvic HGSC and may act as a target for future research on the early detection and prevention of this disease. The newly proposed diagnostic criteria for pelvic HGSC will lead us to more accurate classification of cancer primary sites. Correct classification of HGSC may have potential impacts for cancer prevention and improve our understanding of ovarian serous carcinogenesis.

L1CAM expression associates with poor outcome in endometrioid, but not in clear cell ovarian carcinoma.

OBJECTIVE: Our aim was to study the expression of L1CAM in endometrioid and clear cell ovarian carcinomas and to evaluate its correlation with clinical parameters and patient prognosis. METHODS: Tissue microarray -based immunohistochemical analysis of L1CAM expression was performed in 249 endometrioid and 140 clear cell ovarian carcinomas. Concurrent endometrial carcinoma was found in 57 of these patients. RESULTS: L1CAM expression was found in 15% of endometrioid and 23% of clear cell ovarian carcinomas. L1CAM expression was strongly associated with poor disease-specific overall survival and poor disease-free survival in endometrioid (p<0.0001, p=0.0005), but not in clear cell ovarian carcinomas. Significant association of L1CAM expression with poor overall survival was observed in grade 1-2 carcinomas (p<0.0001), but not in grade 3 tumors. In endometrioid ovarian carcinomas, L1CAM expression was associated with aggressive tumor characteristics, such as higher grade and stage, and incomplete response to primary therapy. However, L1CAM expression was not an independent prognostic factor for overall or disease-free survival. Of the 57 patients with concurrent endometrial carcinoma L1CAM positivity was found in 4 cases both in the ovarian and endometrial tumors, and in 3 cases only in the endometrial tumor. All these seven patients with L1CAM positive tumors had poor outcome. CONCLUSIONS: L1CAM expression could serve as a biomarker for predicting clinical outcome and response to therapy in patients with endometrioid ovarian carcinoma, but not in clear cell carcinomas. L1CAM positivity also predicts poor outcome in patients with concurrent endometrioid ovarian and endometrial carcinomas.

Endometrioid endometrial carcinomas with microcystic, elongated, and fragmented (MELF) type of myoinvasion: role of immunohistochemistry in the detection of occult lymph node metastases and their clinical significance.

In endometrioid endometrial carcinomas (EECs), microcystic, elongated, and fragmented (MELF) myoinvasion is associated with easily overlooked lymph node metastases; however, the role of immunohistochemistry in their detection and their clinical significance have not been addressed. We identified MELF in 43 of 101 (43%) myoinvasive EECs. Nodes were removed in 49 (49%), 25 with MELF and 24 without MELF. Metastases were initially reported in 3 of the former (12%) and 2 of the latter (8%). All negative nodes were reviewed, and cytokeratin immunohistochemistry was performed. Three metastases were identified in the MELF group but none in the EECs without MELF. By immunohistochemistry, metastatic nodal isolated tumor cells (ITCs) were found in 6 of the remaining 19 MELF-positive cases. In contrast, lymph node metastases were detected in only 2 of the 22 EECs without MELF. MELF-positive cases had more lymph node metastases (P=.03) than myoinvasive EECs without MELF. At follow-up, all 6 patients with grade 1-2 EECs and nodal ITCs/micrometastases were alive (5 no evidence of disease and 1 with perineal disease). In contrast, 3 of 4 patients with grade 3 EECs and nodal ITCs/micrometastases died of disease, and the other patient was alive with tumor. In MELF, the frequency of ITCs/micrometastases in apparently negative lymph nodes is high. In patients with grade 1-2 EEC who had not received chemotherapy, the presence of nodal ITCs/micrometastases did not affect survival. In contrast, in high-grade tumors, ITCs/micrometastases were associated with unfavorable prognosis. Immunohistochemistry should be done in MELF-positive cases to detect occult lymph node metastases, especially in high-grade tumors.

L1CAM and HER2 Expression in Early Endometrioid Uterine Cancer.

Recently L1CAM was shown to be a promising biomarker for early-stage endometrial carcinoma (EC). As L1CAM expression was found to be related to serous ECs and areas of serous differentiation in endometrioid carcinomas, there is evidence that L1CAM-positive cancers more likely resemble type II carcinomas. Furthermore, expression of growth factor receptor HER2 has been found to be closely associated with serous ECs. We conducted a retrospective study on 142 patients in FIGO stages I and II with endometrioid EC and analyzed L1CAM and HER2 expression by double-staining immunohistochemistry. The association between these 2 transmembrane molecules and their impact on patient outcome was analyzed. Both L1CAM and HER2 showed a significant association with recurrent disease (P<0.001 and P=0.007, respectively). We found 39 (27%) L1CAM-positive cases and 17 (12%) HER2-positive cases. About 6.3% of cases were positive for both biomarkers. Survival of L1CAM-positive patients showed a significant difference between HER2-positive and HER2-negative patients (P=0.019) regarding disease-free survival. The most unfavorable disease-free survival and overall survival was found for patients with L1CAM and HER2 double-positive tumors (P<0.001). Double immunostaining revealed a mutually exclusive staining pattern for L1CAM and HER2 expression on the level of tumor cells. In early endometrioid uterine carcinoma, an additional expression of HER2 to L1CAM seems to further worsen disease-free survival and overall survival. In terms of "personalized medicine," detection of these molecules in endometrioid ECs may open new avenues for targeted therapies with the newly available anti-HER2 drugs and/or with the upcoming humanized anti-L1CAM antibodies.

Atypical mucinous glandular proliferations in endometrial samplings: follow-up and other clinicopathological findings in 41 cases.

The 2014 World Health Organization classification calls for endometrial mucinous proliferations that display "confluent or cribriform architecture with even minimal atypia" in sampling specimens to be classified as carcinoma, and others whose features are not diagnostic of carcinoma to be categorized as atypical mucinous glandular proliferations (AMGPs). Herein, we evaluate follow-up findings in 41 cases that were classified as AMGP from our files. The average patient age was 46years (range, 37-59 years). Postbiopsy follow-up duration ranged from 15 to 109weeks (mean, 40 weeks). There was no follow-up resection in 12 patients (9 with repeat biopsies, all 9 with no clinical evidence of disease, mean follow-up of 43weeks), and 29 patients underwent a hysterectomy an average of 2.4months after the index biopsy. The distribution of pathologic findings in the uteri was as follows: no residual AMGP or carcinoma (5/29; 17%), AMGP (11/29; 38%), and adenocarcinoma (13/29; 45%). All adenocarcinomas were grade I and stage I, and histotypes were endometrioid (n=8), mucinous (n=3), and endometrioid with mucinous differentiation (n=2). Only 3 (23%) carcinomas were myoinvasive, of which 1 case, a mucinous carcinoma with a 40% endometrioid component, showed greater than 50% myometrial invasion. None of a wide array of morphologic features was significantly associated with a hysterectomy diagnosis of carcinoma (versus AMGP) on univariate analyses. In conclusion, our cohort of AMGP represents a biologically variable spectrum of lesions that includes mucinous hyperplastic proliferations as well as endometrioid and mucinous adenocarcinomas that are occasionally myoinvasive. Morphologic features that optimally stratified AMGP cases into clinically relevant subgroups were not identified.

Morphologic Reproducibility, Genotyping, and Immunohistochemical Profiling Do Not Support a Category of Seromucinous Carcinoma of the Ovary.

The 2014 World Health Organization Classification of Tumors of Female Reproductive Organs endorsed the new category of seromucinous carcinoma, a neoplasm that exhibits morphologic and immunophenotypic overlap with other histotypes of ovarian carcinoma. The goal of this study was to determine whether seromucinous carcinoma was a distinct histotype by assessing its diagnostic reproducibility and comparing its molecular composition to the 5 major histotypes of ovarian carcinoma. Thirty-two tumors diagnosed as seromucinous carcinomas from 2 centers were studied. Eighteen cases were randomly selected for a review set comprising a total of 50 ovarian carcinomas of various histotypes. Morphologic histotype was independently assessed by 4 pathologists. For the 32 seromucinous carcinomas, a histotype-specific immunophenotype was assigned using a diagnostic immunohistochemical panel. Histotype-specific genotype was assigned using a combination of immunohistochemistry and targeted next-generation sequencing for somatic mutations, including genes recurrently mutated in ovarian carcinomas. There was low to modest agreement between pathologists with the reference diagnosis of seromucinous carcinoma, ranging from 39% to 56% for the 4 observers. The immunophenotype was not unique but overlapped predominantly with endometrioid and to a lesser extent with mucinous and low-grade serous carcinoma. Genomic and immunohistochemical alterations were detected in a number of target genes, including KRAS (70%), PIK3CA (37%), PTEN (19%), and ARID1A (16%); no CTNNB1 mutations were identified. Nine cases (30%) harbored concurrent KRAS/PIK3CA mutations. An endometrioid genotype was assigned to 19 cases, a low-grade serous genotype to 9, and a mucinous genotype to 1 and 3 cases were uninformative. Integrating morphology, immunophenotype, and genotyping resulted in reclassifying the seromucinous carcinomas to endometrioid 23/32 (72%), low-grade serous 8/32 (25%), and mucinous 1/32 (3%). The morphologic diagnosis of seromucinous carcinomas is not very reliable and it does not exhibit a distinct immunophenotype or genotype. The molecular features overlap mostly with endometrioid and low-grade serous carcinomas. Our data suggest the category of seromucinous carcinoma be discontinued as ancillary molecular tests can assign cases to one of the major histotypes.

Distinct molecular landscapes between endometrioid and nonendometrioid uterine carcinomas.

Endometrial carcinoma (EC) is traditionally characterized as endometrioid and nonendometrioid based on histopathologic phenotypes. Molecular-based classifications have been proposed, but are not widely implemented. Herein we examine molecular profiles between EC histologic subtypes. 3133 ECs were submitted between March 2011 and July 2014: 1634 Type I and 1226 Type II. In situ hybridization and immunohistochemistry were used to assess copy number and protein expression of selected genes. Sequenced variants in 47 genes were analyzed using the Illumina TruSeq Amplicon Cancer Panel. Type II EC included 628 cases of uterine serous cancer (USC), 136 cases of clear cell (CC), 361 cases of carcinosarcoma (CS), 38 cases of mucinous, and 36 cases of squamous cell. PI3K/Akt/mTOR pathway was most frequently dysregulated within Type I and mucinous histologies, least altered in CS and squamous. PD-L1 expression was highest in mucinous, absent in squamous. ER/PR expression was common in Type II, most frequent in USC, mucinous, and squamous. Receptor tyrosine kinase was frequently dysregulated in Type II disease: HER2 amplification highest in USC and CC, EGFR mutations exclusively seen in mucinous EC, KRAS mutations common in mucinous, squamous, and Type I, and c-MET overexpression high in CC and mucinous. BRCA1 and BRCA2 were most frequently mutated in CS. Grade 3 EC shares features of G1 tumor and Type II disease, most notably resembling CS. Endometrial carcinomas are a molecularly heterogeneous group of tumors. A histology-based molecular map can identify rational targets to optimize treatment and guide future clinical trials.

Microcystic, elongated, and fragmented pattern invasion is mainly associated with isolated tumor cell pattern metastases in International Federation of Gynecology and Obstetrics grade I endometrioid endometrial cancer.

Although many studies have evaluated the impact of mismatch repair protein loss of expression (MMR LOE) or microcystic, elongated, and fragmented (MELF) pattern of myometrial invasion as individual factors in endometrial cancer, we analyzed the combined impact of both. We reviewed every case of International Federation of Gynecology and Obstetrics (FIGO) grade 1 endometrioid endometrial cancers (EECs) from our institution, between 2011 and 2015, that had a sentinel lymph node biopsy and/or a lymphadenectomy, and examined the following data: age, myometrial infiltration, MELF infiltration, lymphovascular space invasion, and lymph node status. These cases were then grouped according to the absence of lymph node metastases, the presence of isolated tumor cell (ITC) lymph node metastases, or the presence of non-ITC metastases. Among the 127 cases that were in our study, 105 patients did not have nodal metastases, whereas 22 patients showed metastases, of which 11 were ITC. MMR LOE was only significantly associated with a higher odds ratio (OR) of metastases (OR, 7.44; P < .001). MELF was only associated with a higher OR of ITC-pattern metastases (OR, 32.3; P < .001). This study distinguished the effects of MELF and MMR LOE on the risk of metastases in FIGO grade 1 EEC. Further research on the clinical impact of MELF and ITC-pattern metastases is warranted to better guide clinicians on the management of patients with FIGO grade 1 EEC harboring such characteristics, which are still considered low-risk cancer.

[Characteristic and clinical significance of DNA methyltransferase 3B overexpression in endometrial carcinoma].

OBJECTIVE: To determine the clinicopathological significance of the DNA methyltransferase 3B (DNMT3B) overexpression in endometrial carcinomas and to evaluate its correlation with hormone receptor status. METHODS: Immunohistochemistry was performed to assess the expression of DNMT3B and hormone receptors in 104 endometrial carcinomas. RESULTS: DNMT3B overexpression occurred frequently in endometrioid carcinoma (EC, 54.8%) more than in nonendometrioid carcinoma (NEC, 30.0%) with statistical significance (P=0.028). Furthermore, there was a trend that EC with worse clinico-pathological variables and shorter survival had a higher DNMT3B expression, and the correlation between DNMT3B and tumor grade reached statistical significance (P=0.019).A negative correlation between DNMT3B and estrogen receptor (ER) or progesterone receptor (PR) expression was found in EC. NMT3B overexpression occurred frequently in the ER or PR negative subgroups (78.9%, 86.7%) more than in the positive subgroups (47.7%, 47.8%) with statistical significance (P=0.016, P=0.006). In addition, the DNMT3B overexpression increased in tumors with both ER and PR negative expression (92.9%, P=0.002). However, no such correlation was found in NEC (P>0.05). Sequence analyses demonstrated multiple ER and PR binding sites in the promoter regions of DNMT3B gene. CONCLUSION: This study showed that the expression of DNMT3B in EC and NEC was different. DNMT3B overexpression in EC was associated with the worse clinicopathological variables and might have predictive value. The methylation status of EC and NEC maybe different. In addition, in EC, DNMT3B overexpression negatively correlated with ER or PR expression. In NEC, the correlation between DNMT3B and ER or PR status was not present.