Comprehensive next-generation sequencing identifies novel putative pathogenic or likely pathogenic germline variants in patients with concurrent tubo-ovarian and endometrial serous and endometrioid carcinomas or precursors.

BACKGROUND: Endometrial serous carcinoma (ESC) and tubo-ovarian high-grade serous carcinoma (HGSC) are characterized by late-stage presentation and high mortality. Current guidelines for prevention recommend risk-reducing salpingo-oophorectomy (RRSO) in patients with hereditary mutations in cancer susceptibility genes. However, HGSC displays extensive genetic heterogeneity with alterations in 168 genes identified in TCGA study, but current germline testing panels are often limited to the handful of recurrently mutated genes, leaving families with rare hereditary gene mutations potentially at-risk. OBJECTIVE: To determine if there are rare germline mutations that may aid in early identification of more patients at-risk for ESC and/or HGSC by evaluating patients with concurrent ESC, HGSC or precursor lesions, and endometrial atypical hyperplasia (CAH) or low-grade endometrial endometrioid adenocarcinoma (LGEEA). METHODS: We performed targeted next-generation sequencing using TSO 500, a 523 gene panel, on formalin-fixed paraffin-embedded tumor and matched benign non-tumor tissue blocks from 5 patients with concurrent ESC, HGSC or precursor lesions, and CAH or LGEEA. RESULTS: We identified germline pathogenic, likely pathogenic or uncertain significance variants in cancer susceptibility genes in 4 of 5 patients - affected genes included GLI1, PIK3R1, FOXP1, FANCD2, INPP4B and H3F3C. Notably, none of these genes were included in the commercially available germline testing panels initially used to evaluate the patients at the time of their diagnoses. CONCLUSION: Comprehensive germline testing of patients with concurrent LGEEA or CAH and ESC, HGSC or precursor lesions may aid in early identification of relatives at-risk for cancer who may be candidates for RRSO with hysterectomy.

HER2 Status Assessment in Endometrial Serous Carcinoma: Comparative Analysis of Two Proposed Testing and Interpretation Algorithms.

HER2 status is now routinely assessed in endometrial serous carcinoma (ESC) due to the reported predictive value of HER2 protein overexpression and/or gene amplification. Herein the authors compare 2 proposed testing and interpretation guidelines for HER2 in ESC. Forty-three consecutive cases of ESC that had been dually tested by both HER2 immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) were interpreted using 2 sets of guidelines. Guideline set 1 (GS1) is the 2018 American Society of Clinical Oncology/College of American Pathologists guidelines for breast cancer. Guideline set 2 (GS2) is a recent proposal that is a slight modification of the enrollment criteria for the clinical trial (NCT01367002) that demonstrated a survival benefit for anti-HER2 therapy in ESC. By IHC, GS1 and GS2, respectively classified 39.5% (17/43) and 28% (12/43) of ESC as HER2-negative, 37.2% (16/43) and 53.4% (23/43) as HER2 equivocal, and 23.2% (10/43) and 18.6% (8/43) as HER2-positive ( P > 0.05 for all). IHC and FISH were highly concordant at the extremes using either set of guidelines, as no cases were found to be IHC3+/FISH-negative or IHC 0-1+/FISH-positive. GS1 and GS2 were comparable regarding the proportion of IHC equivocal cases that were HER2 amplified by FISH (19% vs 23% respectively; [ P = 0.71]). GS1 and GS2 displayed 98% (42/43) concordance regarding the final (IHC and/or FISH-based) classification of tumors as being HER2-positive or negative, and the same 13 cases were ultimately classified as HER2 amplified using either GS1 or GS2. One "discordant" case was classified as HER2-positive using GS2 but HER2-negative using GS1 (HER2 IHC score 2+ using both guidelines, HER2:CEP17 signal ratio of 3, HER2 signal number of 3.4). Six (14%) of the 43 cases (FISH Groups: 2, 3, and 4) would require IHC results to interpret the FISH findings using GS1. Because GS1 requires that the HER2 IHC staining be observed within a homogeneous and contiguous invasive cell population, and this is not a requirement in GS2, GS2 may be better suited for ESC given its frequently heterogeneous staining pattern. Additional studies may be required on the optimal interpretation of problematic dual-probe FISH scenarios in GS2 and the necessity for IHC correlation in such scenarios. Using either set of guidelines, our findings support a reflex testing strategy of restricting FISH testing to cases that are IHC equivocal.

SMARCA4 / BRG1 -deficient Uterine Neoplasm With Hybrid Adenosarcoma and Carcinoma Features: Expanding the Molecular-morphologic Spectrum of SMARCA4 -driven Gynecologic Malignancies.

SMARCA4 gene encodes BRG1 , a member of the SWItch/sucrose non-fermentable protein family involved in epigenetic transcriptional regulation of important cellular processes. In the uterine corpus, SMARCA4 / BRG1 deficiency is associated with a novel class of undifferentiated uterine sarcomas, characterized by younger age onset, rhabdoid histology, focal phyllodiform architecture, high-risk pathologic findings, and dismal prognosis. Herein, we report a case of a 34-year-old Asian woman with a SMARCA4 / BRG1 -deficient uterine tumor fulfilling the clinicopathologic features of an undifferentiated uterine sarcoma. However, the tumor exhibited several unique features that have not been previously emphasized, including (1) conspicuous phyllodiform architecture recapitulating conventional adenosarcoma, (2) rhabdoid tumor cells forming cords and keratin-positive cohesive epithelial islands, and (3) cooccurrence with a spatially distinct and discrete endometrial complex atypical hyperplasia from the rest of the proliferation. By immunohistochemistry, the tumor cells were diffusely positive for synaptophysin, whereas BRG1 was lost. Pertinent molecular findings included frameshift mutations in the SMARCA4 gene, mutations in histone modification and chromatin remodeling genes, including KMT2C , ARID1B , KAT6A , and NCOR1 , and mutations in Wnt signaling involving APC and CTNNB1 . Copy number gain in MDM2 and CDK4 were also identified. The tumor mutation burden was intermediate (6.8/MB) and it was microsatellite stable. On balance, our case exhibited morphologic and molecular features that overlap with (1) an undifferentiated uterine sarcoma, (2) an adenosarcoma with sarcomatous overgrowth, and (3) a mixed adenosarcoma and undifferentiated endometrial carcinoma. These hybrid features further expand the molecular-morphologic spectrum of SMARCA4 / BRG1 -deficient uterine neoplasms.

Neuroendocrine Marker Expression in Primary Non-neuroendocrine Epithelial Tumors of the Ovary: A Study of 551 Cases.

Expression of neuroendocrine (NE) markers in primary ovarian non-NE epithelial tumors has rarely been evaluated. The aim of our study was to evaluate the expression of the most widely used NE markers in these neoplasms and to determine any prognostic significance of NE marker expression. The cohort consisted of 551 primary ovarian tumors, including serous borderline tumors, low-grade serous carcinomas, high-grade serous carcinomas (HGSC), clear cell carcinomas, endometroid carcinomas, mucinous borderline tumors, and mucinous carcinomas. Immunohistochemical analysis was performed using antibodies against INSM1, synaptophysin, chromogranin, and CD56 on tissue microarray. Positivity for INSM1, synaptophysin, chromogranin, and CD56 was most frequently observed in mucinous tumors (48.7%, 26.0%, 41.5%, and 100%, respectively). The positivity for these NE markers was mostly restricted to nonmucinous elements distributed throughout the tumor. The mucinous borderline tumor and mucinous carcinomas groups had similar proportions of positivity (mucinous borderline tumor: 53%, mucinous carcinomas: 39%). In the other tumor types, except for HGSC, there was only focal expression (5%-10%) or negativity for NE markers. HGSC showed high CD56 expression (in 26% of cases). Survival analysis was only performed for CD56 in HGSC as this was the only group with sufficient positive cases, and it showed no prognostic significance. Except for mucinous tumors, expression of NE markers in non-NE ovarian epithelial tumors is low. CD56 expression in HGSC occurs frequently but is without diagnostic or prognostic value.

Clinicopathologic Predictors of Clinical Outcomes in Mammary Adenoid Cystic Carcinoma: A Multi-institutional Study.

Adenoid cystic carcinoma (AdCC) is an uncommon type of invasive breast carcinoma with a favorable prognosis. However, some cases are aggressive. The study aims to define the clinicopathologic predictors of outcome. Clinical, radiological, and pathologic variables were recorded for 76 AdCC cases from 11 institutions. The following histologic characteristics were evaluated by the breast pathologist in each respective institution, including Nottingham grade (NG), percentages of various growth patterns (solid, cribriform, trabecular-tubular), percentage of basaloid component, tumor borders (pushing, infiltrative), perineural invasion, lymphovascular invasion, necrosis, and distance from the closest margin. Various grading systems were evaluated, including NG, salivary gland-type grading systems, and a new proposed grading system. The new grading system incorporated the growth pattern (percent solid, percent cribriform), percent basaloid morphology, and mitotic count using the Youden index criterion. All variables were correlated with recurrence-free survival. Nineteen (25%) women developed local and/or distant recurrence. Basaloid morphology (≥25% of the tumor) was identified in 20 (26.3%) cases and a solid growth pattern (using ≥60% cutoff) in 22 (28.9%) cases. In the univariate analysis, the following variables were significantly correlated with worse recurrence-free survival: solid growth pattern, basaloid morphology, lymphovascular invasion, necrosis, perineural invasion, and pN-stage. In the multivariate analysis including basaloid morphology, pN-stage, lymphovascular invasion, and perineural invasion, basaloid morphology was statistically significant, with a hazard ratio of 3.872 (95% CI, 1.077; 13.924; P =.038). The NG and the new grading system both correlated with recurrence-free survival. However, grade 2 had a similar risk as grade 3 in the NG system and a similar risk as grade 1 in the new grading system. For solid growth patterns and basaloid morphology, using a 2-tier system with 1 cutoff was better than a 3-tier system with 2 cutoffs. Basaloid morphology and solid growth pattern have prognostic values for AdCC, with a 2-tier grading system performing better than a 3-tier system.

Multi-institutional Assessment of Pathologist Scoring HER2 Immunohistochemistry.

The HercepTest was approved 20+ years ago as the companion diagnostic test for trastuzumab in human epidermal growth factor 2 (HER2) or ERBB2 gene-amplified/overexpressing breast cancers. Subsequent HER2 immunohistochemistry (IHC) assays followed, including the now most common Ventana 4B5 assay. Although this IHC assay has become the clinical standard, its reliability, reproducibility, and accuracy have largely been approved and accepted on the basis of concordance among small numbers of pathologists without validation in a real-world setting. In this study, we evaluated the concordance and interrater reliability of scoring HER2 IHC in 170 breast cancer biopsies by 18 breast cancer-specialized pathologists from 15 institutions. We used the Observers Needed to Evaluate Subjective Tests method to determine the plateau of concordance and the minimum number of pathologists needed to estimate interrater agreement values for large numbers of raters, as seen in the real-world setting. We report substantial discordance within the intermediate categories (<1% agreement for 1+ and 3.6% agreement for 2+) in the 4-category HER2 IHC scoring system. The discordance within the IHC 0 cases is also substantial with an overall percent agreement (OPA) of only 25% and poor interrater reliability metrics (0.49 Fleiss' kappa, 0.55 intraclass correlation coefficient). This discordance can be partially reduced by using a 3-category system (28.8% vs 46.5% OPA for 4-category and 3-category scoring systems, respectively). Observers Needed to Evaluate Subjective Tests plots suggest that the OPA for the task of determining a HER2 IHC score 0 from not 0 plateaus statistically around 59.4% at 10 raters. Conversely, at the task of scoring HER2 IHC as 3+ or not 3+ pathologists' concordance was much higher with an OPA that plateaus at 87.1% with 6 raters. This suggests that legacy HER2 IHC remains valuable for finding the patients in whom the ERBB2 gene is amplified but unacceptably discordant in assigning HER2-low or HER2-negative status for the emerging HER2-low therapies.

Primary Mucinous Tumors of the Ovary: An Interobserver Reproducibility and Detailed Molecular Study Reveals Significant Overlap Between Diagnostic Categories.

Primary ovarian mucinous tumors represent a heterogeneous group of neoplasms, and their diagnosis may be challenging. We analyzed 124 primary ovarian mucinous tumors originally diagnosed as mucinous borderline tumors (MBTs) or mucinous carcinomas (MCs), with an emphasis on interobserver diagnostic agreement and the potential for diagnostic support by molecular profiling using a next-generation sequencing targeted panel of 727 DNA and 147 RNA genes. Fourteen experienced pathologists independently assigned a diagnosis from preset options, based on a review of a single digitized slide from each tumor. After excluding 1 outlier participant, there was a moderate agreement in diagnosing the 124 cases when divided into 3 categories (κ = 0.524, for mucinous cystadenoma vs MBT vs MC). A perfect agreement for the distinction between mucinous cystadenoma/MBT as a combined category and MC was found in only 36.3% of the cases. Differentiating between MBTs and MCs with expansile invasion was particularly problematic. After a reclassification of the tumors into near-consensus diagnostic categories on the basis of the initial participant results, a comparison of molecular findings between the MBT and MC groups did not show major and unequivocal differences between MBTs and MCs or between MCs with expansile vs infiltrative pattern of invasion. In contrast, HER2 overexpression or amplification was found only in 5.3% of MBTs and in 35.3% of all MCs and in 45% of MCs with expansile invasion. Overall, HER2 alterations, including mutations, were found in 42.2% of MCs. KRAS mutations were found in 65.5% and PIK3CA mutations in 6% of MCs. In summary, although the diagnostic criteria are well-described, diagnostic agreement among our large group of experienced gynecologic pathologists was only moderate. Diagnostic categories showed a molecular overlap. Nonetheless, molecular profiling may prove to be therapeutically beneficial in advanced-stage, recurrent, or metastatic MCs.

ALK Immunoexpression is Specific for Inflammatory Myofibroblastic Tumor Among Vulvovaginal Mesenchymal Neoplasms.

Gynecologic tract origin of inflammatory myofibroblastic tumor (IMT), a receptor tyrosine kinase fusion driven tumor with malignant potential, is uncommon and mostly involves the uterine corpus where misclassification as a smooth muscle tumor may occur due to overlapping morphologic features. With rare exception, uterine IMT involves ALK rearrangements and exhibits ALK immunoexpression. Molecularly confirmed vulvovaginal IMT has not been reported, but several low-grade mesenchymal tumors in this region exhibit myxoid stroma and/or inflammatory infiltrates that may resemble IMT. The aims of this study were to define the diagnostic specificity of ALK immunoexpression for IMT among a broad spectrum (107 cases) of vulvovaginal mesenchymal tumors in the differential diagnosis of IMT and to report the clinicopathologic features of vulvovaginal IMT identified in our archives or via retrospective ALK staining of otherwise classified vulvovaginal tumors. Review of archives from 5 different centers revealed a single case of vulvar IMT in a 62-yr-old woman. The 2.5 cm well-circumscribed tumor exhibited the typical microscopic features of IMT, namely a loose fascicular distribution of bland spindle cells within a myxoid stroma, accompanied by an infiltrate of plasma cells, lymphocytes, and eosinophils. The tumor cells exhibited expression for smooth muscle actin, desmin, h-caldesmon, and ALK. Break-apart fluorescence in situ hybridization confirmed the presence of ALK rearrangement. The patient did not receive any treatment and is alive without disease 32 mo later. No evidence of ALK expression was detected in any of the other 107 vulvovaginal tumors, which included 14 aggressive angiomyxomas, 2 superficial angiomyxomas, 12 angiomyofibroblastomas, 8 cellular angiofibromas, 15 smooth muscle neoplasms, 10 peripheral nerve sheath tumors, 20 fibroepithelial polyps, and a variety of other low grade mesenchymal tumors. Although vulvovaginal ALK- rearranged IMT is exceedingly rare, the behavior remains to be fully understood. ALK immunohistochemistry, which appears specific for IMT in this anatomic site, is advised in the evaluation of vulvovaginal mesenchymal tumors exhibiting myxoid stroma and/or an inflammatory infiltrate.

Conjunctival Perivascular Epithelioid Cell Neoplasm With RBM10-TFE3 Fusion Presenting as Recurrent Subconjunctival Hemorrhage.

Subconjunctival hemorrhages commonly present to eye care professionals and are frequently regarded as benign self-limited conditions. In selected cases, subconjunctival hemorrhages can be a harbinger of more severe disease. Perivascular epithelioid cell tumors, or PEComas, are rare mesenchymal neoplasms believed to originate from perivascular myoid cells and are rarely present in ocular structures. We present a rare case of a conjunctival perivascular epithelioid cell tumor that initially presented with recurrent subconjunctival hemorrhage. To our knowledge, this is the first description of a PEComa with a RBM10-TFE3 gene fusion, only previously seen with renal cell carcinoma. Physicians should be aware of this rare condition, its location in the fornix and its presentation as a recurrent subconjunctival hemorrhage.

Mucinous Proliferations of the Uterine Corpus: Comprehensive Appraisal of an Evolving Spectrum of Neoplasms.

A variety of endometrial lesions may contain mucinous cells. Herein, the author reviews the literature on the classification and clinicopathologic significance of uterine corpus proliferations with a significant mucinous component, assesses the 2020 World Health Organization classification of such lesions, and presents a diagnostic framework. The key epithelial mucinous lesions include mucinous metaplasia, atypical mucinous glandular proliferation and mucinous carcinoma. Each of these categories are classifiable into "usual" and gastrointestinal subtypes, the latter being indicative of intestinal (presence of goblet cells) and/or gastric-type (abundant, pale eosinophilic or clear cytoplasm and well-defined cell borders) morphology. It has been proposed that at least focal expression of gastrointestinal immunohistochemical markers be required for all gastrointestinal type lesions, and for gastrointestinal type atypical mucinous glandular proliferation and carcinoma, minimality or absence of estrogen receptor expression, and the absence of an endometrioid component. Mucinous carcinomas of the usual type, in which >50% of the tumor is comprised of a mucinous component, are the most common. Morphologic subtypes include mucinous carcinoma with microglandular features and mucinous carcinoma with signet rings (signet ring carcinoma). Endometrioid carcinomas with a less than a 50% mucinous component are classified as endometrioid carcinoma with mucinous differentiation. Several studies have directly compared endometrioid and mucinous carcinomas, the latter presumably of the usual type, with respect to patient outcomes after treatment. All have found no difference in overall and disease free survival between these groups. However, three major studies have found mucinous carcinomas to be associated with a higher risk of lymph node metastases. Nineteen cases of mucinous carcinoma of the gastrointestinal type have been reported, and the limited data on their follow-up after primary treatment suggests that this subtype is more clinically aggressive and should accordingly be classified separately from mucinous carcinomas of the usual type. The morphologic spectrum of mucinous carcinoma of the gastrointestinal type is unclear and continues to evolve. Mucinous change, which may sometimes be extensive, may also be associated with papillary proliferation of the endometrium, adenomyoma of the endocervical type, atypical, and typical adenomyomas. In a curettage or biopsy, intestinal type mucinous epithelium may be indicative of any of the gastrointestinal lesions mentioned above, but may also represent samplings of uterine teratomas, yolk sac tumors, genital and extragenital adenocarcinomas with intestinal differentiation, or low-grade appendiceal mucinous neoplasms that secondarily involve the endometrium.

Endometrial Carcinoma as the Presenting Malignancy in a Teenager With a Pathogenic TP53 Germline Mutation: A Case Report and Literature Review.

Patients with germline TP53 mutations are characterized by the occurrence of multiple early-onset malignancies. The characteristic syndrome is Li-Fraumeni syndrome (OMIM # 151623), an autosomal dominant disorder typified by premenopausal breast carcinoma, adrenal cortical tumors, bone and soft tissue sarcomas, leukemias, and tumors of the brain and spinal cord. Gynecologic malignancies are uncommonly reported in families harboring TP53 mutations, and the predominant tumor type reported is ovarian. Uterine carcinoma has been reported only a handful of times in patients with germline TP53 mutations, none as a presenting tumor in a teenager. We report on an 18-year-old patient who presented with grade 3, high-stage endometrioid endometrial carcinoma. Sequencing detected a single-nucleotide substitution in the TP53 gene (NM_000546.6:c.818G>A), encoding the missense substitution p.Arg273His (R273H) in both the tumor and normal tissue, consistent with a germline mutation. We discuss the biology of the TP53 gene and p53 protein, with emphasis on the R273H mutation. We also review the literature on endometrial carcinoma in patients with germline TP53 mutations.

PTEN Loss and ARID1A Mutation in an HPV-positive Metastatic Adenocarcinoma Diagnosed Almost 18 yr After an Intact Cone Excision for Endocervical Adenocarcinoma In Situ.

There have been previous reports of neoplasms with the morphology of endocervical adenocarcinoma in situ (AIS) that secondarily involve the ovaries, presumably through transtubal spread, with a smaller subset metastasizing to distant sites. These ovarian metastases have been discovered up to 7 yr postexcision of the endocervical lesion, consistent with the known potential for overtly invasive cervical carcinomas to recur late after primary curative management. Herein, we present a case of a premenopausal woman with a pelvic mass classified as metastatic human papillomavirus (HPV)-associated endocervical adenocarcinoma (p16-block immunoreactive, high-risk HPV positive by in situ hybridization with PTEN loss, ARID1A, and PBRM1 mutations detected by qualitative next-generation sequencing), identified 17.7 yr (212 mo) after a fertility-sparing cone excision with negative margins for endocervical AIS [HPV-associated, p16-block immunoreactive; PTEN, and BAF250a (ARID1a) expression retained]. Our case highlights: (1) the potential for a subset of lesions with the morphology of AIS to metastasize, and the extraordinarily long timeframe (almost 18 y, the longest reported to date) during which metastases may still be identified; (2) alterations in PTEN and ARID1A may play a role in the progression of a subset of endocervical carcinomas; and (3) the need for studies to evaluate the utility of incorporating ovarian/pelvic imaging into surveillance protocols following fertility-sparing excisions or ovarian-preserving hysterectomies, during the management of endocervical adenocarcinomas, as well as the need to counsel patients about the small but real risk of delayed discovery of ovarian metastases following fertility-preserving surgeries for AIS.

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.

Revisiting the necessity for routine appendectomies in mucinous neoplasms of the ovary: An evaluation of 460 mucinous ovarian tumors.

Appendectomies are not uncommonly performed following an intraoperative diagnosis of a mucinous ovarian neoplasm, although the evidentiary basis for the practice is relatively limited. The current study is a contemporary re-examination of the issue, based on an analysis of a large single institutional cohort. We assessed whether there are any composite of factors that may be associated with the finding of significant disease in the appendix in this setting following intraoperative consultation (IOC) diagnosis of a mucinous neoplasm on an ovary-based mass. Records for 460 consecutive patients whose ovarian tumors were classified as "mucinous" on IOC (n = 246) and/or permanents (n = 214) were reviewed. The distribution of IOC diagnoses on the 246 tumors were as follows: cystadenoma (114), borderline (55), carcinoma (21), mucinous neoplasm or tumor without definitive classification (53), and probable metastases (3). Appendectomies were performed on 82 (33%) of the 246 cases. In 30 (36%) of these 82 cases, the appendix was grossly normal, the ovarian tumor was unilateral, and there was no intraabdominal/peritoneal disease. Microscopic examination of the appendices in these 30 cases showed no mucinous neoplasms therein, but one case had a grossly inapparent, 4 mm well-differentiated carcinoid. In contrast, among the remaining 52 cases (i.e. those with at least one of the "key abnormal features": intra-abddominal/peritoneal disease and/or appendiceal gross abnormality and/or ovarian tumor bilaterality), 12 neoplasms (23%) were microscopically identified in the appendix (4 adenocarcinomas; 7 LAMN; 1 carcinoid) [p = 0.0256]. Of these 12, a grossly abnormal appendix, intraabdominal/peritoneal disease, and ovarian tumor bilaterality was the sole key abnormal feature in 10, 8 and 4 cases respectively, meaning that requiring that any one feature be present to justify the appendectomy would have missed 17%, 33% and 67% of cases respectively. Only 33% (3/12) cases had all 3 features. Our findings support the emerging body of work that indicates that appendectomies should not be routinely performed during the primary surgery for suspected or confirmed mucinous tumors that involve the ovary, unless there is a specific indication. In our cohort, all identified mucinous appendiceal neoplasms were associated with at least one key abnormal feature (gross abnormalities of the appendix, intraabdominal/peritoneal disease, ovarian tumor bilaterality), which suggests that only in patients that meet these criteria would appendectomies most likely be beneficial.

The Diagnostic Criteria for Chronic Endometritis: A Survey of Pathologists.

While acute endometritis is a reasonably well-defined entity of ascending infection and attendant active inflammation, chronic endometritis is less well defined. As part of a broad effort to define and refine the diagnostic criteria and management of the disease, we conducted a survey of pathologists to understand the variability in diagnostic criteria and implications of the diagnosis of nonspecific, nonobstetric chronic endometritis. Members of national and international professional pathology societies were surveyed utilizing anonymous electronic surveys designed to examine diagnostic criteria, etiological understanding and treatment implications of a pathologic diagnosis of nonspecific, nonobstetric chronic endometritis. There was substantial variability among pathologists in the diagnostic criteria used for making a diagnosis of nonspecific, nonobstetric chronic endometritis, with 28.5% of pathologists using the presence of a single plasma cell for making the diagnosis. There was additional variability in the use of special stains, reporting in the presence of coexisting lesions and the hormonal stage of the endometrium. There were no differences between generalists and specialists in the diagnostic criteria used, except the significantly greater likelihood of specialists making the diagnosis in gestational endometrium. The substantial variability in diagnostic criteria for nonspecific, nonobstetric chronic endometritis among pathologists, including among gynecologic pathologists, has the potential to confound the management of patients. Standardization of diagnostic criteria for chronic endometritis is essential to understand the implications of the diagnosis.

Online Training and Self-assessment in the Histopathologic Classification of Endocervical Adenocarcinoma and Diagnosis of Pattern of Invasion: Evaluation of Participant Performance.

Histopathologic classification of endocervical adenocarcinomas (EAC) has recently changed, with the new system based on human papillomavirus (HPV)-related morphologic features being incorporated into the 5th edition of the WHO Blue Book (Classification of Tumours of the Female Genital Tract). There has also been the introduction of a pattern-based classification system to assess invasion in HPV-associated (HPVA) endocervical adenocarcinomas that stratifies tumors into 3 groups with different prognoses. To facilitate the introduction of these changes into routine clinical practice, websites with training sets and test sets of scanned whole slide images were designed to improve diagnostic performance in histotype classification of endocervical adenocarcinoma based on the International Endocervical Adenocarcinoma Criteria and Classification (IECC) and assessment of Silva pattern of invasion in HPVA endocervical adenocarcinomas. We report on the diagnostic results of those who have participated thus far in these educational websites. Our goal was to identify areas where diagnostic performance was suboptimal and future educational efforts could be directed. There was very good ability to distinguish HPVA from HPV-independent adenocarcinomas within the WHO/IECC classification, with some challenges in the diagnosis of HPV-independent subtypes, especially mesonephric carcinoma. Diagnosis of HPVA subtypes was not consistent. For the Silva classification, the main challenge was related to distinction between pattern A and pattern B, with a tendency for participants to overdiagnose pattern B invasion. These observations can serve as the basis for more targeted efforts to improve diagnostic performance.

Molecular events in the pathogenesis of vulvar squamous cell carcinoma.

Vulvar squamous cell carcinomas (VSCC), which constitute over 90% of vulvar malignancies in adults, are classifiable into 2 subgroups that are mostly clinicopathologically distinct, a classification that is fundamentally based whether or not the tumors are HPV-mediated. In this review, we aim to summarize the recent advances in the understanding of molecular events in the pathogenesis of VSCC, including common and targetable mutations, copy number alterations, epigenetics, noncoding RNAs, and tumor immune microenvironment, which may provide insight into the future management of the disease. These events show substantial differences between the 2 subgroups, although significant areas of overlap exist. Recurrent, driver mutations appear to be substantially more prevalent in HPV(-) VSCC. TP53 mutations are the most common somatic mutations in VSCC overall, and are notably predominant in the HPV(-) VSCC, where 30-88% show a mutation. TP53 mutations are associated with worse patient outcomes, and co-mutations between TP53 and either HRAS, PIK3CA or CDKN2A appear to define subsets with even worse outcomes. A wide variety of other somatic mutations have been identified, including a subset with different mutational frequencies between HPV(+) and HPV(-) VSCC. CDKN2A mutations are common, and have been identified in 21 to 55% of HPV(-) VSCC, and in 2 to 25% of HPV(+) VSCC. Hypermethylation of CDKN2A is the most frequently reported epigenetic alteration in VSCC and the expression of some microRNAs may be associated with patient outcomes. The PTEN/PI3K/AKT/mTOR pathway is commonly altered in HPV(+) VSCC, and is accordingly potentially targetable. HPV-positivity/p16 block expression by immunohistochemistry has been found to be an independent prognostic marker for improved survival in VSCC, and may have some predictive value in VSCC patients treated with definitive radiotherapy. 22-39.3% and 68% of VSCC show EGFR amplification and protein overexpression respectively, although the prognostic and predictive value of an EGFR alteration requires additional study. Recurrent chromosomal gains in VSCCs have been found at 1q, 2q, 3q, 4p, 5p, 7p, 8p, 8q, and 12q, and there may be differential patterns of alterations depending on HPV-status. At least one-third of VSCC patients may potentially benefit from immune checkpoint inhibition therapy, based on a high frequency of PD-L1 expression or amplification, or a high tumor mutational burden. Additional studies are ultimately required to better understand the global landscape of genetic and epigenetic alterations in VSCC, and to identify and test potential targets for clinical application.

Pediatric vulvar malignancies: rare but important to know.

Malignancies of the vulva in the pediatric population are exceptionally rare, which makes it difficult to gain any insight into their clinicopathologic profile. In this review, we summarize all published cases of a vulva malignancy in pediatric patients (≤21 years) reported in the English language literature for the 50-year period between 1970 and 2020. We estimate that less than 100 malignancies have been reported in total, approximately 50% of which were rhabdomyosarcomas. Invasive squamous cell carcinomas, yolk sac tumors, Ewing sarcoma/primitive neuroectodermal tumors (ES/PNET) and melanomas each represented approximately 10% of reported cases. For rhabdomyosarcoma, the alveolar and embryonal subtypes were reported with equal frequency, with both representing 70% of cases combined. The average patient age was 9.8 years. 48% and 35% were Intergroup Rhabdomyosarcoma Study clinical groupings I and III respectively. Managements were generally multimodal, and overall outcomes for the group were favorable. For invasive squamous cell carcinoma, the patients were all in their teenage years, with an average age at diagnosis of 15.2 years. A small subset of cases were associated with human papillomavirus and immunosuppression, and it is possible that immunosuppression has a role in vulvar squamous carcinogenesis in this population. One case was associated with lichen sclerosus. The patients with yolk sac tumors ranged in age from less than 1 year to 20 years (mean 12) and 67% of cases were stage I at presentation. An insufficient number of cases have been reported to define their prognosis, although some cases were notably aggressive. The few reported cases of melanoma are distinctive only because they were all associated with lichen sclerosus, suggestive of some role for the latter in their pathogenesis. The average age of patients reported with ES/PNET was 15 years (range 3.3 to 20). At least half of the reported cases were advanced stage at presentation, and patient outcomes were notably poor: 62.5% were dead of disease at follow-up. Pediatric vulvar malignancies are rare and are mostly comprised of 5 entities. Their accurate pathologic classification is necessary to facilitate optimal management.

Primary adenocarcinomas of the vulva and related structures: An enigmatic and diverse group of tumors✰.

Approximately half of adenocarcinomas that involve the vulva are secondary, either through direct extension or metastases from elsewhere. Primary vulvar adenocarcinomas are rare and encompass a diverse array of neoplasms that are nominally classified based on the presumed tissue or organ of origin, the tumoral phenotype, or both. In this review, we summarize the clinicopathologic features of adenocarcinomas that originate from the vulva and related structures, including the terminal urethra. Adenocarcinomas of this region encompass lesions that are defined by their primary site (such as adenocarcinomas of the Bartholin gland, which by definition must be in the region of the Bartholin gland), histomorphology and immunophenotype (such as clear cell carcinoma and adenocarcinoma of intestinal [cloacogenic] type), or both (such as adenocarcinoma of skene gland origin, which is associated with that specific organ but which also displays a distinctive phenotype that is similar to the phenotype of high grade prostatic adenocarcinoma). Other types, such as mammary-type adenocarcinomas, are presumed to originate from the putative mammary-like glands of the vulva and display a spectrum of pathologic features that are similar to their mammary counterparts. Similarly, vulvar carcinomas of sweat gland origin are pathologically similar to their counterparts in the non-vulvar skin and include a variety of cutaneous adnexal-type malignancies such as apocrine adenocarcinoma and eccrine adenocarcinoma. Some tumors, such as adenoid cystic carcinoma, may represent a Bartholin gland adenocarcinoma, a carcinoma of sweat gland origin, or a carcinoma arising from extramammary Paget disease (EMPD), depending on the context. Invasive carcinomas of various types have been reported in 7-12.7% of EMPD, and these are likely the most common primary glandular malignancy of the vulva. Occasional vulvar adenocarcinomas have been reported to be HPV-associated, although this association has not been established for the broader group of vulvar adenocarcinomas. Rare adenocarcinomas are not classifiable by the aforementioned nosologic scheme, and are designated as vulvar adenocarcinoma NOS.

Prospective multi-institutional evaluation of pathologist assessment of PD-L1 assays for patient selection in triple negative breast cancer.

The US Food and Drug Administration (FDA) approved the PD-L1 immunohistochemical assay, SP142, as a companion test to determine eligibility for atezolizumab therapy in patients with advanced triple negative breast cancer (TNBC) but data in lung cancer studies suggest the assay suffers from poor reproducibility. We sought to evaluate reproducibility and concordance in PD-L1 scoring across multiple pathologists. Full TNBC sections were stained with SP142 and SP263 assays and interpreted for percentage (%) immune cell (IC) staining by 19 pathologists from 14 academic institutions. Proportion of PD-L1 positive cases (defined as ≥1% IC) was determined for each assay as well as concordance across observers. We utilized a new method we call Observers Needed to Evaluate Subjective Tests (ONEST) to determine the minimum number of evaluators needed to estimate concordance between large numbers of readers, as occurs in the real-world setting. PD-L1 was interpreted as positive with the SP142 assay in an average 58% of cases compared with 78% with SP263 (p < 0.0001). IC positive continuous scores ranged from 1 to 95% (mean = 20%) and 1 to 90% (mean = 10%) for SP263 and SP142, respectively. With SP142, 26 cases (38%) showed complete two category (<1% vs. ≥1%) concordance; with SP263, 38 cases (50%) showed complete agreement. The intraclass correlation coefficient (ICC) for two category scoring of SP263 and SP142 was 0.513 and 0.560. ONEST plots showed decreasing overall percent agreement (OPA) as observer number increased, reaching a low plateau of 0.46 at ten observers for SP263 and 0.41 at eight observers for SP142. IC scoring with both assays showed poor reproducibility across multiple pathologists with ONEST analysis suggesting more than half of pathologists will disagree about IC scores. This could lead to many patients either receiving atezolizumab when they are unlikely to benefit, or not receiving atezolizumab when they may benefit.