Nonsclerotic Lichen Sclerosus of Vulva: A Clinicopathologic Analysis.

The International Society of the Study of Vulvovaginal Diseases (ISSVD) recently defined nonsclerotic lichen sclerosus (NSLS) as a scenario wherein the clinical findings are consistent with lichen sclerosus (LS), but no microscopic evidence of dermal sclerosis is found and recognized 4 histologic subcategories. Herein, we present an institutional experience with NSLS, with an emphasis on frequency, application of the ISSVD categories in routine practice, and clinicopathologic correlation. The authors reviewed clinical and pathologic findings for consecutive vulvar biopsies in which LS was a clinical and/or pathologic consideration. Cases were classified as classical/sclerotic LS (CLS), NSLS (per ISSVD criteria), and "unclassified," the latter of which were cases not classifiable as NSLS or CLS, despite a clinical impression or LS or LS being a significant clinical consideration (ie, "clinical LS"). In clinical LS cases, CLS and NSLS were diagnosed histologically in 61% (182/298) and 15% (44/298), respectively, whereas the remainder were histologically unclassified. The latter group was microscopically heterogeneous, devoid of a consistent pathologic profile, and generally showed absence, focality, minimality, ambiguity, or infrequency of features that would have allowed their categorization into one of the NSLS categories. Among the 4 categories for the categorizable NSLS cases, the "lichenoid dermatitis" pattern (61.4%) was the commonest, followed by dermal fibrosis with acanthosis (22.7%), dermal fibrosis without acanthosis (9.1%), and hypertrophic lichenoid dermatitis (6.8%). The clinical response rates to topical therapies for the NSLS and unclassified groups were 71% and 62%, respectively (P=0.4). Our findings highlight the significance of clinicopathologic correlation in the diagnosis of NSLS. In the setting of clinical LS, some histologic evidence to support that impression is found in most cases when the ISSVD system for diagnosis and classification of biopsies is applied. However, a subset of clinical LS cases are not pathologically classifiable as either CLS or any of the NSLS categories; these display nonspecific histologic features and require future study.

Isolated Monoclonal T-Cell Receptor Gene Rearrangement in a Lung Adenocarcinoma Harboring MET Exon 14 Skipping: Diagnostic Pitfall.

In the diagnostic workup of poorly differentiated tumors, T-cell receptor (TCR) clonality has long been considered as evidence of T-cell lymphoma. MET exon 14 skipping (METex14) is a mutation typically seen in lung adenocarcinoma. Herein, we present the first report of METex14 lung adenocarcinoma with isolated monoclonal TCRγ gene rearrangement. A 69-year-old woman presented to an outside hospital with pleural effusions. A pleural decortication demonstrated malignant cells positive for CD30 and CD138 but negative for BerEP4, KRT5, and EMA. An equivocal HHV8 staining was interpreted as positive, leading to the erroneous outside diagnosis of primary effusion lymphoma. Additional workup at our institution revealed a lack of HHV8 and T-cell markers but the presence of TCRγ clonality, pankeratin, and TTF1 expression. Repeat TCRγ testing on the in-house biopsy was negative for clonality. Next-generation sequencing detected METex14, confirming the diagnosis of lung adenocarcinoma. The potential diagnostic pitfall and prognostic/predictive implications are discussed.

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.

The Malignant Potential of Ovarian Steroid Cell Tumors Revisited: A Multi-institutional Clinicopathologic Analysis of 115 Cases.

Steroid cell tumors (SCTs) of the ovary are rare and understudied, and as such, uncertainties remain about their malignant potential, as well as clinicopathologic predictors of patient outcome. Based on a multi-institutional cohort of cases, we present findings from the largest study of SCT reported to date. Clinicopathologic data were documented on 115 cases of SCT that were assembled from 17 institutions. The median patient age was 55 years (range: 9 to 84). When measured, preoperative androgen levels were elevated in 84.2% (48/57) of patients. A total of 111 (96.5%) cases were classified as stage I (103 stage IA; 2 stage IB; 6 stage IC). The stage distribution for the remaining 4 patients was as follows: stage II (n = 1), III (n = 3; 1 IIIA, 1 IIIB, 1 IIIC). The median tumor size was 3 cm (range: 0.2 to 22). Cytologic atypia, microscopic tumor necrosis, microscopic tumor hemorrhage, and a mitotic index of >1 mitotic figure/10 high-power fields were present in 52% (60/115), 9.6% (11/115), 37% (43/115), and 19% (22/115) of cases, respectively. Of 115 patients, 7 (6.1%) recurred postexcision, 4 (3.5%) ultimately died of disease, and 10 (8.7%) either recurred, died of disease, or were advanced stage at presentation. The median duration to recurrence postresection was 33 months (range: 23 to 180). Four of the 7 recurrences were stage IA at baseline. Tumor size >4 cm, International Federation of Gynecology and Obstetrics (FIGO) stage ≥IB, tumor necrosis, and tumor hemorrhage were each significantly associated with reduced recurrence-free survival in log-rank tests and univariable Cox models, with age older than 65 years being of marginal significance (hazard ratio [HR]: 5.4, 95% CI: 1.0-30.0, P = 0.05). Multivariable analyses suggested that FIGO stage ≥IB (HR: 27.5, 95% CI: 2.6-290.5), and age older than >65 years (HR: 21.8, 95% CI: 1.6-303.9) were the only parameters that were independently associated with recurrence. Cross-section analyses showed that tumor necrosis, tumor hemorrhage, and larger tumor size were significantly associated with a FIGO stage ≥IB status, which bolstered the conclusion that they are not independent predictors of recurrence. In summary, <10% of SCTs are clinically malignant, a substantially lower frequency than has previously been reported in the literature. Clinicopathologic predictors of patient outcomes that are prospectively applicable in practice could not be definitively established. Recurrences may occur many years (up to 15 y in this study) after primary resection, even in stage IA cases.

Ovarian steroid cell tumors: what do we know so far?

Steroid cell tumors (SCT) of the ovary are rare, which has limited advances in the understanding of this enigmatic neoplasm. In this review, we summarize currently known clinicopathologic information on SCT. SCT are frequently hormonally active, leading to elevated serum and/or urine levels of androgenic hormones or their metabolites, and associated symptomatology, including virilization. The reported age at diagnosis is broad and has ranged from as young as 1 year old to 93 years old, although most patients were between ages 20 and 40 years. Most tumors are stage I and unilateral. The tumors are usually well circumscribed with a solid or solid to cystic cut surface. The tumors in one series reportedly ranged in size from 1.2 to 45 cm (average 8.4 cm). MRI is a useful imaging modality, typically showing a well delineated mass with contrast enhancement and lipid content on T2 and T1 weighted images, respectively. Microscopically, SCT display polygonal to epithelioid cells with abundant eosinophilic to vacuolated/clear cytoplasm and display an immunoprofile that is consistent with sex cord-stromal differentiation. Most cases are benign, without any recurrences after primary resection, but a subset - probably less than 20% of cases -are clinically malignant. Pathologic criteria that can specifically predict patient outcomes remain elusive, although features that correlate with adverse outcomes have been proposed based on retrospective studies. The molecular characteristics of SCTs are similarly under characterized, although there is some evidence of an enrichment for hypoxia-signaling gene mutations in SCT. In malignant SCT, the tumors generally show greater global genomic instability, copy number gains in oncogenes, and occasional BAP1 mutation. Future studies involving multi-institutional cohort and unbiased molecular profiling using whole exome/transcriptome sequencing are needed to help advance our molecular understanding of SCTs.

Selective breast/gynecologic pathology fellowship training in the United States: Experience of program directors.

Published data on combined breast and gynecologic [breast/gyn] surgical pathology fellowship training programs are limited. Our study aimed to survey the landscape of such fellowships in the United States (US), including specific information about their characteristics and the educational activities therein. Using web searches, we identified programs offering combined breast/gyn surgical pathology fellowship training. We developed a 26-item questionnaire asking program directors to report on the characteristics of their fellowship training structure. The search revealed 25 academic based programs offering one-year combined breast/gyn fellowship training, predominantly located (40 %) in the Northeast area. The following data was obtained: 44 % of the programs were accredited by the ACGME, 82 % required >19 weeks of breast and gyn service, and 69.6 % accepted the common application, 54.5 % of programs require completion of a research project for graduation. An annual average of 3000 breast and 3000 gyn cases appears to be the usual volume of cases. Interestingly, only 36 % of the program directors are graduates of a combined breast/gyn fellowship program. In conclusion, we present the most comprehensive and up-to-date census of combined breast/gyn pathology fellowships in the US. Our study provides valuable information on the current state of combined breast/gyn pathology fellowship training. The information will be helpful to current and prospective trainees, as well as program leaders.

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.

Fumarate Hydratase-Deficient Leiomyoma of the Uterine Corpus: Comparative Morphologic Analysis of Protein-Deficient Tumors With and Without Pathogenic Germline Fumarate Hydratase Gene Mutations.

Deficiency of fumarate hydratase (FH) protein expression in uterine corpus leiomyomas may be attributable to either germline or somatic mutations of the FH gene, the former being definitional for the hereditary leiomyomatosis and renal cell cancer syndrome. The authors assess whether, using previously reported FH-associated morphologic features, FH protein-deficient uterine corpus leiomyomas associated with a pathogenic germline mutations of the FH gene (group 1) are distinguishable from FH protein-deficient uterine corpus leiomyomas without such mutations (and whose FH protein loss is presumed to be attributable to somatic/epigenetic inactivation or other unknown phenomena: group 2). Groups 1 and 2 were compared regarding a variety of clinicopathologic features, including 7 core "FH-associated" tumoral morphologic features: staghorn vasculature; alveolar-type edema; bizarre nuclei; chain-like tumor nuclei; hyaline cytoplasmic globules; prominent nucleoli, intranuclear inclusions, and perinucleolar halos; and prominent eosinophilic/fibrillary cytoplasm. Among 2418 patients diagnosed with uterine corpus leiomyoma during the study period, FH-associated morphologic features were reported in 1.5% (37 patients), and FH immunohistochemistry was performed in 29 (1.19%). Fourteen (48.27%) of the 29 patients showed FH protein deficiency by immunohistochemistry. Twelve patients underwent germline testing, of which 8 (66.7%) were classified as group 1 and 4 (33.3%) as group 2. FH protein-deficient tumors were larger (10.44 vs 4.08 cm, P = 0.01) and associated with younger patients (42.05 vs 47.97, P = 0.004) than 370 randomly selected uterine leiomyoma controls. Groups 1 and 2 showed no significant differences in patient age and tumor size. In group 1 tumors, the FH-associated morphologic features were generally present diffusely; all group 1 tumors displayed ≥5 FH-associated features, whereas all group 2 tumors displayed <5 FH-associated features (means 6.5 ± 0.53 vs 3.5 ± 1.00, P < 0.001). Notably, eosinophilic/fibrillary cytoplasm and alveolar-type edema were each significantly more prevalent in group 1 tumors than group 2 tumors (P = 0.018 for both). No single morphologic feature was found to be completely sensitive and specific in making the distinction between group 1 and 2 tumors. Our findings suggest that groups 1 and 2 are unlikely to be morphologically distinguishable by individual morphologic features. Whether there is a combination of features that can reliably make this distinction is unclear and will require additional studies with larger cohorts.

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.

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.

GATA3 Expression in HPV-associated and HPV-independent Vulvar Squamous Cell Carcinomas: Patterns of Expression and Prognostic Significance.

Substantial diminution or loss of GATA3 expression is reportedly frequent in human papillomavirus-independent (HPVI), p53-mediated vulvar intraepithelial neoplasia. Herein, we study GATA3 expression in vulvar squamous cell carcinoma (VSCC) and assess its clinicopathologic significance. Eighty-six cases of VSCC diagnosed at a single institution were immunohistochemically assessed for their expression of GATA3, as well as any possible relationships with patient outcomes and other clinicopathologic parameters. Given that GATA3 expression pattern in the normal vulvar epidermis is typically strong basal staining with a uniform upward extension until at least the mid epidermal layers, VSCCs were scored using a previously reported tripattern system: pattern 0 (>75% tumor staining), pattern 1 (25% to 75% staining), and pattern 2 (<25% staining). Severe loss of GATA3 expression (pattern 2) was present in both human papillomavirus-associated (HPVA) and HPVI VSCC but was significantly more common in HPVI cases ( P <0.001). Among 52 HPVA VSCCs, 16 (30.7%), 15 (28.8%), and 21 (40.3%) cases showed patterns 0, 1, 2 staining whereas among 34 HPVI VSCCs, the respective frequencies were 1 (2.9%), 5 (14.7%), and 28 (82.3%). None of the 30 p53 abnormal VSCCs showed pattern 0 staining (0%). Five (16.6%) and 25 (83.3%) showed patterns 1 and 2 staining, respectively. On univariate analysis, the pattern 2 cohort showed a significantly worse overall survival (OS) and disease-free survival (DFS) than the pattern 0 or 1 cohort ( P =0.011 and 0.024, respectively), but this finding was not independent of stage on multivariate analysis ( P =0.34; hazard ratio: 1.82; 95% CI: 0.55-6.06). Subgroup analysis of the p53 wild-type cases showed significantly worse OS for pattern 2 than the pattern 0 or 1 cohorts, independent of stage ( P =0.04; hazard ratio: 6.5; 95% CI: 1.08-39.8). Subgroup analysis of p53 abnormal cases, however, showed no difference in OS and DFS among the 3-tiered GATA3 cohorts. In summary, loss of GATA3 may be seen in both HPVA and HPVI VSCCs but is significantly more common in HPVI SCCs. Loss or substantial diminution of GATA3 expression (pattern 2) is a negative prognostic factor in vulvar SCCs, but only in the p53 wild-type subset, where its negative prognostic significance appears to be independent of stage.

Refined criteria for p53 expression in ovarian mucinous tumours are highly concordant with TP53 mutation status, but p53 expression/TP53 status lack prognostic significance.

In gynecological neoplasms, immunohistochemical (IHC) expression of p53 is generally an accurate predictor of TP53 mutation status if correctly interpreted by the pathologist. However, the literature concerning cut-offs, frequency and prognostic significance of p53 staining in ovarian mucinous tumours is limited and heterogeneous. We performed an analysis of 123 primary ovarian mucinous tumours including mucinous borderline tumours (MBT), mucinous carcinomas (MC), and tumours with equivocal features between MBT and MC. We assessed p53 expression for the three recognised patterns of aberrant staining in ovarian carcinoma [overexpression ('all'), null and cytoplasmic] but using a recently suggested cut-off for aberrant overexpression in ovarian mucinous tumours (strong nuclear p53 staining in ≥12 consecutive tumour cells) and correlated the results with next generation sequencing (NGS) in all qualitatively sufficient cases (92/123). Aberrant p53 expression was present in 25/75 (33.3%) MBT, 23/33 (69.7%) MC (75% of MC with expansile invasion and 61.5% with infiltrative invasion), and 10/15 (66.7%) tumours equivocal between MBT and MC. Regarding the 92 tumours with paired IHC and mutation results, 86 showed concordant results and six cases were discordant. Three discordant MBT cases showed aberrant expression but were TP53 wild-type on sequencing. Three cases had normal p53 expression but contained a TP53 mutation. Overall, IHC predicted the TP53 mutation status with high sensitivity (94.1%) and specificity (92.7%). The accuracy of IHC was 93.5% with a positive predictive value of 94.1% and a negative predictive value of 92.7%. When comparing MC cases with wild-type TP53 versus those with TP53 mutation, there were no significant differences concerning disease-free survival, local recurrence-free survival, or metastases-free survival (p>0.05). In the MBT subgroup, there were no events for survival analyses. In conclusion, using an independent large sample set of ovarian mucinous tumours, the results of our study confirm that the suggested refined cut-off of strong nuclear p53 staining in ≥12 consecutive tumour cells reflect high accuracy, sensitivity and specificity for an underlying TP53 mutation but the TP53 mutation status has no prognostic significance in either MC or MBT.

GATA3 immunohistochemistry as a diagnostic adjunct for differentiated vulvar intraepithelial neoplasia: utility and limitations.

Herein, the authors evaluate the diagnostic utility and limitations of GATA3 immunohistochemistry for the distinction of differentiated vulvar intraepithelial neoplasia (dVIN) from its potential mimics. Immunohistochemical studies for GATA3, p53, and p16 were performed on 124 pathologic vulvar tissues, inclusive of dVIN (n = 21), vulvar aberrant maturation (n = 10), high-grade squamous intraepithelial lesion (HSIL) (n = 44), and 49 non-neoplastic vulvar dermatoses of various types. GATA3 expression was scored using a modification of previously proposed criteria: pattern 0 (no significant loss of basal layer staining, >75% staining), pattern 1 (25-75% staining), and pattern 2 (<25% staining). With the exception of lichen sclerosus, 8% of which showed pattern 1 or 2 staining, all other non-neoplastic lesions showed pattern 0 expression. Aberrant GATA3 expression (i.e., patterns 1 or 2) was present in 90% of dVIN cases (2 [9.5%], 3 [14.3%], 16 [76.2%] with patterns 0, 1, and 2 respectively), 90% of vulvar aberrant maturation cases (1 [10%],7 [70%], 2 [20%] with patterns 0, 1, and 2 respectively), and 15.9% of HSIL cases (84.1% pattern 0; 2.3% pattern 1; 13.6% pattern 2). All HSIL cases were p16 positive, including the 7 pattern 1 and 2 cases. All cases of dVIN-like HSIL were pattern 0, and all (n = 2) cases of HSIL-like (basaloid) dVIN were pattern 2 (both of the latter cases displayed complete absence of epidermal staining). Only 1 dVIN case was both pattern 0 and p53-wild-type. We conclude that GATA3 is useful for the distinction of dVIN from non-neoplastic dermatoses and from HSIL, but is best used as part of a panel that includes p53 and p16 to mitigate its limitations.

Microsatellite instability in non-endometrioid ovarian epithelial tumors: a study of 400 cases comparing immunohistochemistry, PCR, and NGS based testing with mutation status of MMR genes.

Testing of microsatellite instability is not only used as a triage for possible Lynch syndrome, but also to predict immunotherapy treatment response. The aim of this study was to assess the frequency of mismatch repair deficiency (MMR-D)/microsatellite instability (MSI) in 400 cases of non-endometrioid ovarian tumors (high-grade serous, low-grade serous, mucinous and clear cell), to compare different methodological approaches of testing, and to assess the optimal approach for next generation sequencing (NGS) MSI testing. For all tumors, we evaluated immunohistochemical (IHC) expression of MMR proteins and assessed microsatellite markers by PCR-based method. Except for high-grade serous carcinoma, we correlated the findings of IHC and PCR with NGS-based MSI testing. We compared the results with somatic and germline mutation in MMR genes. Among the whole cohort, seven MMR-D cases, all clear cell carcinomas (CCC), were found. On PCR analysis, 6 cases were MSI-high and one was MSS. In all cases, mutation of an MMR gene was found; in 2 cases, the mutation was germline (Lynch syndrome). An additional 5 cases with a mutation in MMR gene(s) with MSS status and without MMR-D were identified. We further utilized sequence capture NGS for MSI testing. Employing 53 microsatellite loci provided high sensitivity and specificity. Our study shows that MSI occurs in 7% of CCC while it is rare or absent in other nonendometrioid ovarian neoplasms. Lynch syndrome was present in 2% of patients with CCC. However, some cases with MSH6 mutation can evade all testing methods, including IHC, PCR, and NGS-MSI.

Fallopian tubal histogenesis of ovarian endometriosis-A study of folate receptor-alpha expression.

Background: Ovary is a common organ site involved by endometriosis. We previously found that fallopian tube may contribute to the histogenesis of ovarian endometriosis. The finding was novel and requires further studies. We addressed this issue by examining a differentially expressed gene folate receptor alpha (FOLR1) and its protein (FRA) in this study. Results: A total of 144 tissue samples were studied. These included 32-paired tubal-endometrial-ovarian endometriosis samples (n = 96), 18 samples of ovarian endometriosis without corresponding fallopian tube or endometrium, and 30 ovarian tissue samples with ovarian surface epithelia but without endometriosis. Multiple comparisons among groups of ovarian endometriosis, normal fallopian tube and benign endometrium were performed. FOLR1 was highly expressed in the epithelia of fallopian tube and ovarian endometriosis, with paired endometrial samples showing a significantly lower level of expression. Similar differential studies for FRA protein were performed through Western blot and immunohistochemistry (IHC). The expression of folate receptor alpha at both mRNA and protein levels in the tissues (fallopian tube or ovarian endometriosis vs. the endometrium) were significantly different (p < 0.001). All ovarian surface mesothelial epithelia showed negative expression of FRA by IHC. Conclusion: The results further support that the fallopian tube may contribute to the development of ovarian endometriosis. Understanding the tubal contribution to ovarian endometriosis should ultimately contribute to ongoing investigative efforts aimed at identifying alternative ways to prevent and treat endometriosis. High level of FRA expression in the fallopian tube and endometriosis might be considered as potential tissue sites for targeted therapy.

A comprehensive immunohistochemical analysis of IMP2 and IMP3 in 542 cases of ovarian tumors.

BACKGROUND: IMP2 and IMP3 are mRNA binding proteins involved in carcinogenesis. We examined a large cohort of ovarian tumors with the aim to assess the value of IMP2 and IMP3 for differential diagnosis, and to assess their prognostic significance. METHODS: Immunohistochemical analyses with antibodies against IMP2 and IMP3 were performed on 554 primary ovarian tumors including 114 high grade serous carcinomas, 100 low grade serous carcinomas, 124 clear cell carcinomas, 54 endometrioid carcinomas, 34 mucinous carcinomas, 75 mucinous borderline tumors, and 41 serous borderline tumors (micropapillary variant). The associations of overall positivity with clinicopathological characteristics were evaluated using the chi-squared test or Fisher's Exact test. RESULTS: We found IMP2 expression (in more than 5% of tumor cells) in nearly all cases of all tumor types, so the prognostic meaning could not be analyzed. The positive IMP3 expression (in more than 5% of tumor cells) was most common in mucinous carcinomas (82%) and mucinous borderline tumors (81%), followed by high grade serous (67%) and clear cell carcinomas (67%). The expression was less frequent in endometrioid carcinomas (39%), low grade serous carcinomas (23%), and micropapillary variant of serous borderline tumors (20%). Prognostic significance of IMP3 could be evaluated only in low grade serous carcinomas in the case of relapse-free survival, where negative cases showed better RFS (p = 0.033). CONCLUSION: Concerning differential diagnosis our results imply that despite the differences in expression in the different ovarian tumor types, the practical value for diagnostic purposes is limited. Contrary to other solid tumors, we did not find prognostic significance of IMP3 in ovarian cancer, with the exception of RFS in low grade serous carcinomas. However, the high expression of IMP2 and IMP3 could be of predictive value in ovarian carcinomas since IMP proteins are potential therapeutical targets.