Expression and Prognostic Significance of LAG-3, TIGIT, VISTA, and IDO1 in Endometrial Serous Carcinoma.

Endometrial serous carcinoma (ESC) is an uncommon, aggressive type of endometrial cancer. While immune checkpoint blockade has emerged as a promising treatment option for endometrial carcinomas, research on the expression of immune checkpoints that could serve as prospective immunotherapy targets in ESC is limited. We examined the prevalence and prognostic value of lymphocyte-activation gene 3 (LAG-3), T-cell immunoglobulin and ITIM domain (TIGIT), V-domain immunoglobulin (Ig) suppressor of T-cell activation (VISTA), and indoleamine 2,3-dioxygenase 1 in 94 cases of ESC and correlated their expression with CD8+ and FOXP3+ tumor-infiltrating lymphocytes (TILs). We observed a positive correlation among LAG-3, TIGIT, and VISTA expressed on immune cells, and among these markers and CD8+ and FOXP3+ TIL densities. In Kaplan-Meier survival analysis, tumors with high levels of LAG-3 and TIGIT expression had better progression-free survival (PFS) and overall survival (OS) than those with lower levels of expression (LAG-3: PFS, P = .03, OS, P = .04; TIGIT: PFS, P = .01, OS, P = .009). In multivariate analysis, only high TIGIT expression was of independent prognostic value for better OS. VISTA expression in immune or tumor cells, and indoleamine 2,3-dioxygenase 1 expression in tumor cells, did not show a significant association with survival. Our data indicate that LAG-3, TIGIT, and VISTA immune checkpoints have roles in the microenvironment of ESC, and their expression patterns highlight the complex interactions among the different components of this system. High levels of these markers, together with high CD8+ TIL, suggest the potential immunogenicity of a subset of these tumors. Further studies are needed to elucidate the roles of various immune components in the ESC microenvironment and their association with intrinsic tumor properties.

Utility of a PAX2, PTEN, and ß-catenin Panel in the Diagnosis of Atypical Hyperplasia/Endometrioid Intraepithelial Neoplasia in Endometrial Polyps.

The diagnosis of atypical hyperplasia/endometrioid intraepithelial neoplasm (AH/EIN) within endometrial polyps (EMPs) often poses a diagnostic conundrum. Our previous studies demonstrated that a panel of immunohistochemical (IHC) markers consisting of PAX2, PTEN, and ß-catenin can be effectively utilized for the identification of AH/EIN. A total of 105 AH/EIN within EMP were analyzed using the 3-marker panel. We also evaluated these cases for the presence of morules. Benign EMP (n=90) and AH/EIN unassociated with polyp (n=111) served as controls. Aberrant expression of PAX2, PTEN, or ß-catenin was observed in AH/EIN in EMP in 64.8%, 39.0%, and 61.9% of cases, respectively. At least 1 IHC marker was abnormal in 92.4% of cases. Overall, 60% of AH/EIN in EMP demonstrated abnormal results for≥2 IHC markers. The prevalence of PAX2 aberrancy was significantly lower in AH/EIN in EMP than in nonpolyp AH/EIN (64.8% vs. 81.1%, P =0.007), but higher than in benign EMP (64.8% vs. 14.4%, P <0.00001). The prevalence of ß-catenin aberrancy was significantly higher in AH/EIN in EMP than in nonpolyp AH/EIN (61.9% vs. 47.7%, P =0.037). All control benign EMP demonstrated normal expression of PTEN and ß-catenin. Morules were present in 38.1% of AH/EIN in EMP versus 24.3% in nonpolyp AH/EIN, and absent in benign EMP. A strong positive association was found between ß-catenin and morules (Φ=0.64). Overall, 90% cases of atypical polypoid adenomyoma (n=6) and mucinous papillary proliferation (n=4) showed IHC marker aberrancy. In conclusion, the 3-marker IHC panel (PAX2, PTEN, and ß-catenin) is (1) a useful tool in the diagnosis of AH/EIN in EMP; (2) PAX2 loss should be interpreted with caution and in combination with morphology and other markers.

COL1A1-PDGFB Fusion Associated Fibrosarcoma of the Uterine Corpus: A Case Report and Literature Review.

Uterine collagen type 1 alpha 1 (COL1A1) and platelet-derived growth factor beta chain (PDGFB) fusion associated fibrosarcoma is a recently described entity characterized by a specific translocation t(17;22) (q22;q13) leading to the formation of COL1A1-PDGFB fusion transcripts that are typically associated with dermatofibrosarcoma protuberans. So far, only 4 cases of COL1A1-PDGFB fusion associated fibrosarcoma involving the female reproductive system have been reported in the literature. All cases showed strong diffuse expression of CD34. COL1A1-PDGFB fusion associated fibrosarcomas are aggressive tumors with a propensity for chemotherapy resistance and a poor prognosis. We are reporting the fifth case of a uterine COL1A1-PDGFB fusion associated fibrosarcoma. A 58-yr-old female presented with a large uterine mass with extension into bilateral pelvic sidewalls, mesentery of rectosigmoid colon and the vagina. A hysterectomy, bilateral salpingo-oophorectomy, and tumor debulking procedure was performed. Microscopic evaluation revealed a mitotically active cellular spindle cell neoplasm with focal osteoclast like giant cells, myxoid changes and necrosis. CD34 was diffusely and strongly positive throughout the tumor. Next-generation sequencing showed presence of the COL1A1-PDGFB fusion. The patient was treated with multiple chemotherapy regimens, however, progressed under therapy with worsening symptoms and development of extensive pelvic disease. She died of disease 13 mo after the initial diagnosis. In summary, uterine COL1A1-PDGFB fusion associated fibrosarcomas are rare tumors with aggressive clinical behavior that need to be considered in the differential diagnosis of CD34-positive uterine spindle cell neoplasms. Novel treatment options may include imatinib, a tyrosine kinase inhibitor used for treatment of advanced and unresectable dermatofibrosarcoma protuberans that was given in 1 uterine sarcoma case and showed promising initial response.

Prevalence and prognostic significance of PD-L1, TIM-3 and B7-H3 expression in endometrial serous carcinoma.

Endometrial serous carcinoma (ESC) is an aggressive type of endometrial carcinoma with a poor prognosis. Immune checkpoint blockade has evolved as a novel treatment option for endometrial cancers; however, data on expression of immune checkpoints that may be potential targets for immunotherapy in ESC are limited. We analyzed the prevalence and prognostic significance of PD-L1, TIM-3 and B7-H3 immune checkpoints in 99 ESC and evaluated their correlation with CD8 + tumor infiltrating lymphocytes. Applying the tumor proportion score (TPS) with a cutoff of 1%, PD-L1, TIM-3 and B7-H3 expression was present in 17%, 10% and 93% of cases, respectively. Applying the combined positive score (CPS) with a cutoff of 1, PD-L1, TIM-3 and B7-H3 expression was present in 63%, 67% and 94% of cases, respectively. Expression of these markers was largely independent of one another. PD-L1 correlated with higher CD8 + T-cell density when evaluated by either TPS (p = 0.02) or CPS (p < 0.0001). TIM-3 correlated with CD8 + T-cell density when evaluated by CPS (p < 0.0001). PD-L1 positivity was associated with improved overall survival (p = 0.038) when applying CPS. No association between PD-L1 expression and survival was found using TPS, and there was no association between TIM-3 or B7-H3 positivity and survival by either TPS or CPS. Using TPS, PD-L1 correlated with a higher tumor stage but not with survival, whereas the converse was true when PD-L1 was evaluated by CPS, suggesting that PD-L1 expression in immune cells correlates with prognosis and is independent of tumor stage. In conclusion, PD-L1, TIM-3 and B7-H3 may be potential therapeutic targets in selected patients with ESC. Further investigation of their roles as predictive biomarkers is needed.

Morules But Not Squamous Differentiation are a Reliable Indicator of CTNNB1 (ß-catenin) Mutations in Endometrial Carcinoma and Precancers.

Although collectively regarded as "squamous differentiation (SD)" in endometrial endometrioid carcinoma (EEC) and atypical hyperplasia/endometrioid intraepithelial neoplasia (AH/EIN), morules (often referred to as "squamous morules") and true SD may represent two distinct phenomena. Here, we explored the distinction between morules versus SD and investigated the association of morules and SD with CTNNB1 mutations. A total of 270 cases of EEC and AH/EIN were studied, including EEC with (n=36) or without (n=36) morules and AH/EIN with (n=80) or without (n=118) morules. Cases were analyzed by immunohistochemistry and selected cases (n=20) by targeted next-generation sequencing panel. Near-perfect agreement was found between morules and glandular ß-catenin nuclear staining in AH/EIN and EEC. A strong positive association was found between morules and glandular ß-catenin nuclear staining ( P <0.0001, Φ=0.59 in AH/EIN; P <0.0001, Φ=0.85 in EEC). There was no association between (1) morules and glandular PAX2 or PTEN aberrant expression or (2) SD and aberrant expression of ß-catenin, PAX2 or PTEN (Φ=0.09, ß-catenin; Φ=0.16, PAX2; Φ=0.13, PTEN). CTNNB1 mutations were identified in all 20 selected morule-containing cases (100%). Next-generation sequencing was performed on 2 (preprogestin and postprogestin treatment) biopsies from 1 patient, revealing identical mutational profile in morules and glands. In conclusion, (1) SD and morules are distinct biological phenomena; (2) the presence of morules, but not SD, is a reliable indicator of CTNNB1 mutations in EEC and AH/EIN. Our findings demonstrate that SD and morules are distinct biological phenomena. Since morules but not SD are associated with ß-catenin mutations, the distinction is clinically relevant and should be included in diagnostic reports.

Gestational trophoblastic disease- rare, sometimes dramatic, and what we know so far.

Gestational trophoblastic disease (GTD) is a heterogeneous group of lesions that are characterized by the abnormal proliferation of the trophoblast. Morphology, behavior and clinical significance vary tremendously and range from benign, non-neoplastic lesions that cause sometimes dysfunctional uterine bleeding to aggressive, highly, malignant tumors. The recently updated 2020 World Health Organization (WHO) Classification of Female Genital Tumors divides GTD in molar pregnancies/ hydatidiform moles, gestational trophoblastic neoplasms, tumor-like lesions and abnormal (nonmolar) villous lesions. In this article we review the typical clinical presentations of GTDs, their histopathologic features, contributing immunohistochemical stains and current diagnostic criteria. We discuss novel insights in the proposed pathogenesis, newly proposed entities and advances in ancillary diagnostic techniques and their relevance to the histopathologic diagnosis of GTD. Additionally we briefly review current treatment options, prognosis and prognostic factors of GTDs.

Rare Complete Hydatidiform Mole With p57 Expression in Villous Mesenchyme: Case Report and Review of Discordant p57 Expression in Hydatidiform Moles.

Complete hydatidiform mole (CHM) is a premalignant proliferative disease of the placenta characterized by misexpression of imprinted gene products, most notably p57. The majority of CHM exhibit immunohistochemical absence of p57 protein in villous mesenchyme (VM) and cytotrophoblast (CT) and are thus p57 VM/CT concordant. However, some gestations show loss of p57 in only VM or CT, either in all chorionic villi or a subset thereof (VM/CT discordant). Here, we present a rare case of a p57 VM/CT-discordant CHM with diffuse retention of p57 expression in VM but complete absence in CT. Histologically, the case exhibited typical features of CHM including trophoblast hyperplasia and severe nuclear atypia, but was unusual in the presence of gestational membranes identified ultrasonographically and histologically. Ploidy determination by FISH and genotyping by short tandem repeat analyses showed that this was a diploid gestation with variable allelic ratios and with an androgenetic lineage, similar to previously reported p57 VM/CT-discordant cases.

Reliable Identification of Endometrial Precancers Through Combined Pax2, ß-Catenin, and Pten Immunohistochemistry.

The diagnosis of endometrial atypical hyperplasia/endometrioid intraepithelial neoplasia (AH/EIN) remains challenging and subjective in some cases, with variable histologic criteria and differences of opinion among gynecologic pathologists, potentially leading to under/overtreatment. There has been growing interest in the use of specific immunohistochemical markers as adjuncts in AH/EIN diagnosis. For example, the World Health Organization 2020 Classification specifies that loss of Pten, Pax2, or mismatch repair proteins are desirable diagnostic criteria. Other markers, most notably ß-catenin and Arid1a, are also aberrantly expressed in some AH/EIN. However, the performance of some markers individually-and more importantly as a group-has not been rigorously explored, raising questions as to which marker(s) or combination(s) is the most effective in practice. Formalin-fixed paraffin-embedded tissue sections from AH/EIN cases (n=111) were analyzed by immunohistochemistry for 6 markers: Pax2, Pten, Mlh1, ß-catenin, Arid1a, and p53. Aberrant expression was tabulated for each case and marker. An additional set of normal endometria (n=79) was also analyzed to define optimal diagnostic criteria for marker aberrance. The performance characteristics of each marker, the entire panel, and subsets thereof were quantitatively and statistically analyzed. In order of number of cases detected, the most frequently aberrant markers in AH/EIN were Pax2 (81.1% of cases), Pten (50.5%), ß-catenin (47.7%), Arid1a (7.2%), Mlh1 (4.5%), and p53 (2.7%). The majority of cases showed aberrant expression of ≥2 markers. All 6 markers together identified 92.8% of cases. Arid1a, Mlh1, and p53 were robust and readily scored markers, but all cases showing aberrant expression of these 3 markers were also detected by Pax2, Pten, or ß-catenin. A focused panel of only 3 markers (Pax2, Pten, and ß-catenin) showed optimal performance characteristics as a diagnostic adjunct in the histopathologic diagnosis of AH/EIN. Use of this panel is practicable and robust, with at least 1 of the 3 markers being aberrant in 92.8% of AH/EIN.

Navigating through perplex morphologic changes after exogenous hormone usage.

Clinical application of exogenous hormone as a method of contraception and/or treatment of various gynecologic disorders is exceedingly common. Unfortunately, the concurrent use of these agents also complicates the interpretation of pathology specimens. Various studies have shown that morphologic changes induced by hormonal therapies are present in both non-neoplastic and neoplastic tissues within the women's reproductive tract. It is important to understand the exogenous hormone induced morphologic changes, as it helps the pathologists make the accurate diagnosis, and in turn, guide clinicians to make optimal clinical decisions. In this review, we summarize the morphologic changes in both neoplastic and non-neoplastic endometrial, cervical, and myometrial surgical specimens after hormonal therapies, particularly after progestin treatment. In the endometrium, particularly in the scenario of progestin-treated atypical endometrial hyperplasia/endometrioid intraepithelial neoplasia (AEH/EIN), there is notoriously poor interobserver agreement and difficulty in assessing for the residual disease. We summarize current literature and propose our recommended approach in assessing these challenging endometrial biopsies, including a diagnostic algorism, the use of PAX-2, PTEN, beta-catenin immunohistochemistry panel, as well as consistency in diagnostic wording of the report. In the cervix, progestin makes dysplastic lesions appear metaplastic, thus high-grade squamous dysplastic lesions may be easily missed. Within the myometrium, lesions such as adenomyosis may show various degree of decidualization, while smooth muscle neoplasms may show apoplectic changes, and stromal lesions including endometrial stromal sarcoma may show more eosinophilic cytoplasm. All such changes may pose more or less diagnostic challenges in our daily practice. However, most are readily recognizable when we understand particular hormone related scenarios.

PD-L1 Expression in Endocervical Adenocarcinoma: Correlation With Patterns of Tumor Invasion, CD8+ Tumor-infiltrating Lymphocytes, and Clinical Outcomes.

Programmed death-1 ligand (PD-L1) expression has been used as a predictive marker for response to immune checkpoint inhibitors and has been reported to have prognostic value. Its prevalence and significance in endocervical adenocarcinoma (ECA) remain underinvestigated. We evaluated PD-L1 expression and CD8+ tumor-infiltrating lymphocyte density in whole tissue sections of 89 ECAs. PD-L1 expression was observed in 68% of ECAs by combined positive score (CPS, cutoff 1) and 29% of ECAs by tumor proportion score (TPS, cutoff 1%). Using CPS, PD-L1 expression was seen in 11%, 78%, and 72% of pattern A, B, and C tumors, respectively, with significantly higher expression in tumors with destructive-type invasion (B and C) (P=0.001 [A vs. B], 0.0006 [A vs. C], 0.0002 [A vs. B+C]). Using TPS, no significant difference in PD-L1 expression was seen between tumors with different invasion patterns (0%, 22%, and 32% in tumors with pattern A, B, and C, respectively; P=0.27 [A vs. B], 0.053 [A vs. C], 0.11 [A vs. B+C]). PD-L1-positive ECAs demonstrated significantly higher CD8+ tumor-infiltrating lymphocyte density (CPS: P=0.028; TPS: P=0.013) and worse progression-free survival when compared with PD-L1-negative ECAs (CPS: hazard ratio [HR]=4.253 vs. 0.235, P=0.025; TPS: HR=4.98 vs. 0.2; P=0.004). When invasion patterns were separately assessed, pattern C tumors similarly showed worse progression-free survival in PD-L1-positive tumors (CPS: HR=6.15 vs. 0.16, P=0.045; TPS: HR=3.78 vs. 0.26, P=0.027). In conclusion, our data show frequent PD-L1 expression in ECA with destructive-type invasion, supporting the role of the PD-1/PD-L1 pathway as a therapeutic target for these tumors. Our data also support PD-L1 as a negative prognostic marker associated with a potentially unfavorable outcome.

Specific Biomarker Expression Patterns in the Diagnosis of Residual and Recurrent Endometrial Precancers After Progestin Treatment: A Longitudinal Study.

BACKGROUND: Conservative management with progestin is a treatment option for atypical hyperplasia (AH). However, pathologic diagnosis of residual/recurrent lesions is often problematic because of the profound morphologic changes induced by progestin and the lack of established diagnostic criteria for progestin-treated residual AH. METHODS: We conducted a longitudinal study of 265 endometrial biopsies from 54 patients with a history of AH on progestin therapy. Patient outcomes were divided into 3 categories after morphologic review and immunohistochemical staining with phosphatase and tensin homolog (PTEN) and paired box 2 (PAX2): (1) persistent or residual disease; (2) recurrent disease; (3) complete response. All specimens were classified into 3 categories based on morphology: (1) persistent/recurrent disease (nonresponse), (2) morphologically uncertain response, (3) optimally treated (complete response). The staining patterns of PTEN/PAX2 were tracked over time in individual patients and correlated with morphologic findings before and after progestin therapy. RESULTS: Our data showed that aberrant expression patterns of PTEN and/or PAX2 were identified in 48 (88.9%) of the 54 primary biopsies and persisted in persistent/recurrent AH across serial endometrial biopsies (n=99, P<0.00001), while normal PTEN and PAX2 expressions were consistently observed in optimally treated cases (n=84, P<0.00001). More importantly, follow-up biopsies that showed a morphologically uncertain response but a PTEN/PAX2 expression pattern identical to the initial biopsy were significantly correlated with persistent or recurrent disease (n=18, P=0.000182), as evidenced by areas with morphologic features diagnostic of AH on subsequent biopsy. CONCLUSIONS: Biomarker PTEN/PAX2 signatures offer a valuable diagnostic aid to identify residual AH in progestin-treated endometrial samples for which the biomarker status from preprogestin treated AH is known. The findings of this study are promising for a possible future change of diagnostic practice.

PD-L1 Expression and CD8+ Tumor-infiltrating Lymphocytes in Different Types of Tubo-ovarian Carcinoma and Their Prognostic Value in High-grade Serous Carcinoma.

The prevalence and significance of programmed death-1 ligand (PD-L1) expression in different types of tubo-ovarian carcinoma have not been well defined. We evaluated PD-L1 expression and CD8 tumor-infiltrating lymphocyte (TIL) density in whole tissue sections of 189 cases of tubo-ovarian carcinoma, including high-grade serous carcinoma (HGSC, n=100), clear cell carcinoma (CCC, n=24), endometrioid carcinoma (EmC, n=40), and mucinous carcinomas (MC, n=25). Using the tumor proportion score (TPS) with a 1% cutoff, PD-L1 expression was present in 21% of HGSC, 16.7% of CCC, 2.5% of EmC, and 4% of MC. Using the combined positive score (CPS) with a cutoff of 1, PD-L1 expression was present in 48% of HGSC, 25% of CCC, 20% of EmC, and 24% of MC. HGSC demonstrated significantly higher CD8 TIL density than CCC (P=0.013238), EmC (P=0.01341), or MC (P=0.004556). In HGSC, CD8 TIL density was directly correlated with PD-L1 positivity using either TPS (P=0.0008) or CPS (P=0.00011). Survival analysis of patients with high stage (stage III to IV) HGSC revealed PD-L1 positivity by TPS to be associated with improved progression-free survival (adjusted hazard ratio: 0.4912 vs. 2.036, P=0.0378). Although not statistically significant, a similar trend was observed in overall survival (adjusted hazard ratio: 0.3387 vs. 2.953, P=0.0548). In contrast, with CPS, no significant difference was identified between PD-L1-positive and negative groups in either progression-free survival (P=0.5086) or overall survival (P=0.7823). Neoadjuvant chemotherapy was associated with higher PD-L1 expression by TPS (P=0.00407) but not CPS. No significant difference in PD-L1 expression was detected in tumors from patients with germline BRCA1/2 mutations compared with germline mutation-negative tumors by either TPS or CPS. In conclusion, the prevalence of PD-L1 expression is variable in different types of tubo-ovarian carcinoma and is highest in HGSC. In high-stage HGSC, PD-L1 positivity in tumor cells is associated with an increased immune response and improved survival.

Cervical Adenocarcinoma: Histopathologic Features From Biopsies to Predict Tumor Behavior.

The pattern-based classification system of endocervical adenocarcinoma correlates with nodal metastasis and clinical outcomes, but its application in biopsies is challenging. The aim of this study was the correlation of additional histologic features with patterns of invasion as well as prognosis. A total of 103 specimens from 71 cervical adenocarcinoma cases were studied. Among the 71 cases, all had resection specimens including hysterectomy, cold knife cone excision or loop electrosurgical excision procedure excision, and 32 of these had prior cervical biopsies. We applied the pattern-based classification system to all the specimens and evaluated histopathologic features microscopically. Findings in biopsies were compared with their corresponding resections and correlated with nodal status and disease stage. In 71 resection specimens, pattern A was present in 10 (14.1%), pattern B in 12 (16.9%), and pattern C in 49 (69%) cases. Of the 32 cervical biopsies, pattern of invasion could be classified in only 16 (50%) cases, including 1 (6%) with pattern A, 4 (25%) with pattern B, and 11 (69%) with pattern C. Of the 32 cervical biopsies, 30 could be evaluated for intraluminal necrotic/tumor debris and/or grade 3 nuclei, which correlated with pattern C as well as with lymph node metastasis in the subsequent staging specimens. No tumor with patterns A or B had intraluminal necrotic/tumor debris or grade 3 nuclei in either biopsy or resection specimens. Therefore, intraluminal necrotic/tumor debris and grade 3 nuclei are highly predictive histologic features for cervical adenocarcinomas with pattern C invasion and nodal metastasis.

Mass lesions of the myometrium: interpretation and management of unexpected pathology.

PURPOSE OF REVIEW: Uterine leiomyomas are the most common benign uterine smooth muscle tumors. On the basis of imaging, these masses are often presumed to be benign conventional leiomyomas and surgical excision is a common treatment choice. After myomectomy or hysterectomy for presumed leiomyomas, the surgical pathology report may reveal an unexpected diagnosis of another type of mesenchymal tumor. These can range from a variant of benign smooth muscle tumors to smooth muscle tumors of uncertain malignant potential to malignant sarcomas. This review describes these variant pathologies and reviews data on recurrence risk and postoperative management. RECENT FINDINGS: The majority of benign smooth muscle tumors will be classified as leiomyomas. Cellular, bizarre nuclei, mitotically active, epitheliod, myxoid, and dissecting are all terms that describe pathologic variants of benign leiomyomas. Smooth muscle tumors of uncertain malignant potential contain both benign and malignant features and should be referred to Gynecologic Oncology for follow-up. Leiomyosarcomas and low-grade endometrial stromal sarcomas may present preoperatively as benign tumors but are malignant with a high risk of recurrence and should be referred to Gynecologic Oncology. SUMMARY: We advocate for the continued benefits of minimally invasive procedures in appropriately selected patients. Despite these measures, unexpected pathologic diagnoses can occur and should be managed appropriately.

Targeted Molecular and Immunohistochemical Analyses of Endometrial Clear Cell Carcinoma Show that POLE Mutations and DNA Mismatch Repair Protein Deficiencies Are Uncommon.

Endometrial clear cell carcinoma (ECCC) is an uncommon histotype without unique identified molecular alterations. Recently, The Cancer Genome Atlas molecular subtypes have been reported in ECCC. ECCC cases were collected from 11 institutions with diagnoses confirmed by morphologic review and immunohistochemistry. DNA mismatch repair (MMR) proteins, p53 expression, and ARID1A expression was assessed by immunohistochemistry on tissue microarrays. Targeted next-generation sequencing was completed for POLE, TP53, KRAS, and PIK3CA. Pathogenicity of mutations was determined using MutationTaster and PolyPhen databases. For p53, immunohistochemistry and sequencing were complimentarily used to assess the p53 status. Of 57 cases, 46 were considered prototypical ECCC by morphology and immunohistochemical profile (Napsin A-positive and ER-negative). Three cases were excluded because of insufficient sample for complete immunohistochemical analysis, and 6 had failed sequencing, resulting in 37 cases. Of the 37 remaining cases, 6/37 (16%) had predicted pathogenic mutations in the exonuclease domain of POLE with an allelic frequency >10%; however, no hot-spot mutations were identified. No cases were MMR-deficient. The gene most commonly affected was TP53 (59%, 22/37), followed by KRAS (13%, 2/15) and PIK3CA (13%, 2/15). The current study is the largest molecular analysis of pure ECCC reported to date. When strict classification criteria are applied, MMR-deficient and POLE mutated subtypes are not represented. Further consensus on what represents a deleterious POLE mutations is needed. The findings support separately studying histologically/immunohistochemically defined ECCC to identify characteristic molecular alterations in future studies.

Clear Cell Renal Cell Carcinoma Metastatic to the Gynecologic Tract: A Clinicopathologic Analysis of 17 Cases.

Clear cell renal cell carcinomas (CCRCC) rarely metastasizes to the gynecologic tract. In this study, we analyzed a multi-institutional data set to provide insights into the clinical, morphologic, and immunophenotypic features of this phenomenon. Seventeen metastatic CCRCC involving the gynecologic tract [ovary/fallopian tube (n=9), vulva (n=2), uterine corpus (n=3), cervix (n=2), uterine serosa (n=1)] were analyzed. Mean patient age was 62 yr (range: 45-79 yr). Most cases (15/17) presented as a recurrence 6 to 72 mo postnephrectomy, 1 case was concurrently diagnosed, and 1 case (a cervical metastasis) was diagnosed prenephrectomy. In 10 cases, metastases to other locations were identified within 6 wk of the gynecologic tract lesion. The adnexa were the most common site of metastases and the mean tumor size of adnexal metastases was 3.7 cm; in only 2 of 9 cases were metastases bilateral and only 1 had external surface nodules. The morphologic and immunohistochemical features of metastatic CCRCC were compared with those of 102 müllerian clear cell carcinomas (müllerian CCC: 49 endometrial, 53 ovarian). Although CCRCC and müllerian CCC displayed extensive morphologic overlap, a higher mitotic index and a higher frequency of an alveolar pattern were seen in CCRCC, whereas diffuse hobnail cells, hyaline globules, tubulocystic pattern, or any papillary pattern were more frequently seen in müllerian CCC. CA-IX, CD10, and renal cell carcinoma antigen were more frequently expressed in CCRCC than müllerian CCC, whereas Napsin-A, CK7, and p504S showed the reverse. PAX8 and HNF1ß did not significantly distinguish between the 2 groups. In summary, gynecologic tract metastases most often occur as a relapse of a previously resected CCRCC, and these relapses may occur many years postnephrectomy. Gynecologic tract metastases are often accompanied by concurrent metastases to other organs. The gross pathology of metastatic CCRCC in the ovary may potentially overlap with primary neoplasia. However, the expected morphology and immunophenotype of CCRCC are maintained in most gynecologic tract metastases. As such, although metastatic CCRCC and müllerian CCC may display significant overlap in pathologic features, several morphologic and immunophenotypic features are useful in their distinction.

The Stem Cell-associated Transcription Factor SOX2 as a Diagnostic Marker of High-grade Squamous Intraepithelial Lesion of the Uterine Cervix in Comparison With p16 and Ki-67.

The transcription factor SOX2 has been identified as an oncogene involved in the pathogenesis of squamous cell carcinoma (SCC) of multiple sites, including the uterine cervix. The relationship between SOX2 overexpression and the continuum of precancerous lesions of the cervix has not been previously elucidated. We evaluated SOX2 immunohistochemical expression in normal cervix, low-grade squamous intraepithelial lesion (LSIL) (mild squamous dysplasia), high-grade squamous intraepithelial lesion (HSIL) (moderate and severe dysplasia) and SCC of the cervix in comparison with p16 and Ki-67. Staining patterns were scored as negative, basal one third of the epithelium, lower two third, or full thickness. The results showed that SOX2 expression was limited to the basal one third in 84% of LSIL cases, whereas 95% of HSIL showed SOX2 expression up to two third or full thickness (P<0.0001). p16 and Ki-67 displayed similar results. The difference in SOX2 expression between moderate and severe dysplasia was not statistically significant (P=0.53). Invasive SCC positivity was as follows: SOX2 94%; p16 89%; and Ki-67 100%. Our findings support a role for SOX2 in the progression of squamous dysplasia to SCC. The Lower Anogenital Standardization Terminology Project's recent assertion of a lack of a biological correlate to cervical intraepithelial neoplasia II is also upheld by SOX2. For equivocal situations in which a diagnosis of cervical intraepithelial neoplasia II would have been made, Lower Anogenital Standardization Terminology recommends p16, or other biomarkers such as Ki-67 to clarify the diagnosis. SOX2, with a clean nuclear staining pattern, may also be suitable for this role.

Prolactin Receptor-Mediated Internalization of Imaging Agents Detects Epithelial Ovarian Cancer with Enhanced Sensitivity and Specificity.

Poor prognosis of ovarian cancer, the deadliest of the gynecologic malignancies, reflects major limitations associated with detection and diagnosis. Current methods lack high sensitivity to detect small tumors and high specificity to distinguish malignant from benign tissue, both impeding diagnosis of early and metastatic cancer stages and leading to costly and invasive surgeries. Tissue microarray analysis revealed that >98% of ovarian cancers express the prolactin receptor (PRLR), forming the basis of a new molecular imaging strategy. We fused human placental lactogen (hPL), a specific and tight binding PRLR ligand, to magnetic resonance imaging (gadolinium) and near-infrared fluorescence imaging agents. Both in tissue culture and in mouse models, these imaging bioconjugates underwent selective internalization into ovarian cancer cells via PRLR-mediated endocytosis. Compared with current clinical MRI techniques, this targeted approach yielded both enhanced signal-to-noise ratio from accumulation of signal via selective internalization and improved specificity conferred by PRLR upregulation in malignant ovarian cancer. These features endow PRLR-targeted imaging with the potential to transform ovarian cancer detection. Cancer Res; 77(7); 1684-96. ©2017 AACR.

Are clear cell carcinomas of the ovary and endometrium phenotypically identical? A proteomic analysis.

Phenotypic differences between otherwise similar tumors arising from different gynecologic locations may be highly significant in understanding the underlying driver molecular events at each site and may potentially offer insights into differential responses to treatment. In this study, the authors sought to identify and quantify phenotypic differences between ovarian clear cell carcinoma (OCCC) and endometrial clear cell carcinoma (ECCC) using a proteomic approach. Tissue microarrays were constructed from tumor samples of 108 patients (54 ECCCs and 54 OCCCs). Formalin-fixed samples on microarray slides were analyzed by matrix-assisted laser desorption/ionization mass spectrometry, and 730 spectral peaks were generated from the combined data set. A linear mixed-effect model with random intercept was used to generate 93 (12.7%) peaks that were significantly different between OCCCs and ECCCs at the fold cutoffs of 1.5 and 0.667 and an adjusted P value cutoff of 1.0 × 10(-10). Liquid chromatography-tandem mass spectrometry was performed on selected cores from each group, and peptides identified therefrom were compared with lists of statistically significant peaks from the aforementioned linear mixed-effects model to find matches within 0.2 Da. A total of 53 candidate proteins were thus identified as being differentially expressed in OCCCs and ECCCs, 45 (85%) of which were expressed at higher levels in ECCCs than OCCCs. These proteins were functionally diverse and did not highlight a clearly dominant cellular theme or molecular pathway. Although ECCCs and OCCCs are very similar, some phenotypic differences are demonstrable. Additional studies of these differentially expressed proteins may ultimately clarify the significance of these differences.