International Journal of Gynecological Pathology最新文献

{"title":"Divergent Malignant Melanocytic Differentiation in Ovarian Endometrioid Adenocarcinoma With Aberrant β-Catenin Expression: A Case Expanding the Histologic Spectrum of β-Catenin Activated Gynecologic Neoplasia.","authors":"Jin Xu, Paul S Weisman","doi":"10.1097/PGP.0000000000000992","DOIUrl":"10.1097/PGP.0000000000000992","url":null,"abstract":"<p><p>Divergent differentiation in gynecologic carcinomas encompasses a broad range of lineages, including mesenchymal, germ cell, high-grade neuroendocrine, neuroectodermal, and cutaneous adnexal differentiation. Here we present a case of ovarian endometrioid adenocarcinoma with divergent malignant melanocytic differentiation (MMeD). The background ovarian endometrioid adenocarcinoma showed focally aberrant β-catenin expression and histologic patterns associated with β-catenin activation, including spindled elements and corded and hyalinized foci. The areas with MMeD had both spindled and epithelioid morphology, diffusely aberrant β-catenin expression, expression of melanocytic markers (an HMB45/Mart-1 cocktail, MITF, and S100), and no staining for myogenic markers (SMA and desmin) or epithelial markers (cytokeratins and E-cadherin). INI1, BRG1, PMS2, and MSH6 were retained, and p53 showed a wild-type expression pattern. No areas with definitive carcinosarcomatous differentiation were identified despite extensive sampling. While a single case of gynecologic carcinosarcoma with a serous epithelial component and a small focus on malignant melanoma has been reported in the English literature, the current case represents what is, to the best of our knowledge, the first case of MMeD arising in the context of a β-catenin activated endometrioid adenocarcinoma. Pathogenetic and differential diagnostic considerations are discussed.</p>","PeriodicalId":14001,"journal":{"name":"International Journal of Gynecological Pathology","volume":" ","pages":"302-307"},"PeriodicalIF":2.4,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71481323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Proposal of Novel Binary Grading Systems for Cervical Squamous Cell Carcinoma.","authors":"Simona Stolnicu, Aaron M Praiss, Douglas Allison, Basile Tessier-Cloutier, Jessica Flynn, Alexia Iasonos, Lien Hoang, Cristina Terinte, Anna Pesci, Claudia Mateoiu, Ricardo R Lastra, Takako Kiyokawa, Rouba Ali-Fehmi, Mira Kheil, Esther Oliva, Kyle Devins, Nadeem Abu-Rustum, Robert A Soslow","doi":"10.1097/PGP.0000000000000979","DOIUrl":"10.1097/PGP.0000000000000979","url":null,"abstract":"<p><p>We compared grading systems and examined associations with tumor stroma and survival in patients with cervical squamous cell carcinoma. Available tumor slides were collected from 10 international institutions. Broders tumor grade, Jesinghaus grade (informed by the pattern of tumor invasion), Silva pattern, and tumor stroma were retrospectively analyzed; associations with overall survival (OS), progression-free survival (PFS), and presence of lymph node metastases were examined. Binary grading systems incorporating tumor stromal changes into Broders and Jesinghaus grading systems were developed. Of 670 cases, 586 were reviewed for original Broders tumor grade, 587 for consensus Broders grade, 587 for Jesinghaus grade, 584 for Silva pattern, and 556 for tumor stroma. Reproducibility among grading systems was poor (κ = 0.365, original Broders/consensus Broders; κ = 0.215, consensus Broders/Jesinghaus). Median follow-up was 5.7 years (range, 0-27.8). PFS rates were 93%, 79%, and 71%, and OS rates were 98%, 86%, and 79% at 1, 5, and 10 years, respectively. On univariable analysis, original Broders ( P < 0.001), consensus Broders ( P < 0.034), and Jesinghaus ( P < 0.013) grades were significant for OS; original Broders grade was significant for PFS ( P = 0.038). Predictive accuracy for OS and PFS were 0.559 and 0.542 (original Broders), 0.542 and 0.525 (consensus Broders), 0.554 and 0.541 (Jesinghaus grade), and 0.512 and 0.515 (Silva pattern), respectively. Broders and Jesinghaus binary tumor grades were significant on univariable analysis for OS and PFS, and predictive value was improved. Jesinghaus tumor grade ( P < 0.001) and both binary systems (Broders, P = 0.007; Jesinghaus, P < 0.001) were associated with the presence of lymph node metastases. Histologic grade has poor reproducibility and limited predictive accuracy for squamous cell carcinoma. The proposed binary grading system offers improved predictive accuracy for survival and the presence of lymph none metastases.</p>","PeriodicalId":14001,"journal":{"name":"International Journal of Gynecological Pathology","volume":" ","pages":"203-214"},"PeriodicalIF":2.4,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11031322/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138798934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dedifferentiated Leiomyosarcoma-morphology, Immunohistochemistry, and Molecular Findings of a Case and Review of Literature.","authors":"Aisha Kousar, Abigail I Wald, Michelle Heayn, Nicholas D Cardillo, Esther Elishaev, Rohit Bhargava","doi":"10.1097/PGP.0000000000000986","DOIUrl":"10.1097/PGP.0000000000000986","url":null,"abstract":"<p><p>We present a case of uterine dedifferentiated leiomyosarcoma in a 42-yr-old woman who presented with severe abdominal pain and vaginal bleeding. The mass measured 10.5 cm. The \"differentiated\" tumor component ranged from leiomyoma-like areas to smooth muscle tumor of uncertain malignant potential to frank leiomyosarcoma. The undifferentiated tumor component showed extreme hypercellularity, intermediate to large polygonal cells, with significant cytologic atypia and numerous mitotic figures (67 mitotic figures per 10 high-power fields). This undifferentiated component imperceptibly blended into more recognizable smooth muscle areas. In contrast to the differentiated component, the undifferentiated component lacked staining for smooth muscle markers. Targeted next-generation sequencing revealed TP53 , NF1 , and NOTCH2 mutations in both differentiated and undifferentiated components. In addition, the undifferentiated tumor component also harbored multiple additional chromosomal abnormalities including gains in 1q, 22q, and copy number losses in 3p, 9p, and 11q. The undifferentiated tumor component was also identified in an adhesion involving the small bowel and omentum at complete staging. The patient was subsequently treated with 6 cycles of adriamycin chemotherapy. Computerized tomography scan after 3 cycles showed no residual disease. Published literature regarding dedifferentiated leiomyosarcoma is reviewed.</p>","PeriodicalId":14001,"journal":{"name":"International Journal of Gynecological Pathology","volume":" ","pages":"264-270"},"PeriodicalIF":1.6,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71481321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hematoxylin and Eosin Staining Helps Reduce Maternal Contamination in Short Tandem Repeat Genotyping for Hydatidiform Mole Diagnosis.","authors":"Yating Zhao, Luya Cai, Xiaofei Zhang, Huifang Zhang, Limeng Cai, Lin Zhou, Bo Huang, Jianhua Qian","doi":"10.1097/PGP.0000000000000973","DOIUrl":"10.1097/PGP.0000000000000973","url":null,"abstract":"<p><p>Short tandem repeat (STR) genotyping provides parental origin information about aneuploidy pregnancy loss and has become the current gold standard for hydatidiform mole diagnosis. STR genotyping diagnostic support most commonly relies on formalin-fixed paraffin-embedded samples, but maternal contamination is one of the most common issues based on traditional unstained sections. To evaluate the influence of hematoxylin and eosin (H&E) staining on DNA quality and STR genotyping, DNA was isolated from unstained, deparaffinized hydrated, and H&E-stained tissue sections (i.e. 3 groups) from each of 6 formalin-fixed paraffin-embedded placentas. The macrodissected view field, DNA quality, and polymerase chain reaction amplification efficiency were compared among groups. STR genotyping analysis was performed in both the test cohort (n = 6) and the validation cohort (n = 149). H&E staining not only did not interfere with molecular DNA testing of formalin-fixed paraffin-embedded tissue but also had a clearer macrodissected field of vision. In the test cohort, H&E-stained sections were the only group that did not exhibit maternal miscellaneous peaks in STR genotyping results. In the validation cohort, 138 (92.62%) cases yielded satisfactory amplification results without maternal contamination. Thus, H&E staining helped to reduce maternal contamination in STR genotyping for hydatidiform mole diagnosis, suggesting that H&E-stained sections can be incorporated into the hydatidiform mole molecular diagnostic workflow.</p>","PeriodicalId":14001,"journal":{"name":"International Journal of Gynecological Pathology","volume":" ","pages":"253-263"},"PeriodicalIF":2.4,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11022989/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9976728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular Classification of Endometrial Endometrioid Carcinoma With Microcystic Elongated and Fragmented Pattern.","authors":"Baohui Ju, Jianghua Wu, Lin Sun, Chunrui Yang, Hu Yu, Quan Hao, Jianmei Wang, Huiying Zhang","doi":"10.1097/PGP.0000000000000980","DOIUrl":"10.1097/PGP.0000000000000980","url":null,"abstract":"<p><p>The studies on the molecular classification of endometrioid carcinoma (EC) with microcystic, elongated, and fragmented (MELF) pattern invasion are limited. In this study, 77 cases of ECs with MELF patterns in Chinese women were collected. The molecular classification of the fifth edition of the World Health Organization was used to classify the molecular subtypes using immunohistochemistry staining (mismatch repair [MMR]-immunohistochemistry: MSH2, MSH6, MLH1, and PMS2; p53) and Sanger sequencing targeted POLE . The results showed that the prevalence of the 4 molecular subtypes in EC with MELF pattern was 6.5% (5/77) for POLE mutation, 20.8% (16/77) for MMR deficient, 11.7% (9/77) for p53-mutant, and 61.0% (47/77) for no specific molecular profile. The clinicopathological characteristics of each subtype were compared. The p53-mutant and no specific molecular profile subgroups were associated with higher International Federation of Gynecology and Obstetrics stage and International Federation of Gynecology and Obstetrics grade, deeper myometrial invasion, lymphovascular space invasion, lymph node metastasis, and absence of tumor-infiltrating lymphocytes, whereas the POLE mutation and MMR deficient subgroups were associated with lower aggressive features and prominent tumor-infiltrating lymphocytes. Progression-free survival showed that the p53-mutant and no specific molecular profile subgroups had a poorer prognosis than the POLE mutation and MMR deficient subgroups. However, lymph node metastasis was an independent factor associated with a higher risk of disease recurrence in multivariate analysis. In conclusion, ECs with MELF patterns can be divided into 4 molecular subtypes with discrepancies in aggressive clinicopathological characteristics and tumor-infiltrating lymphocytes. Molecular classification has clinical significance in a morpho-molecular approach for ECs with MELF patterns.</p>","PeriodicalId":14001,"journal":{"name":"International Journal of Gynecological Pathology","volume":" ","pages":"233-241"},"PeriodicalIF":2.4,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41138256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Endometrioid Adenocarcinoma With \"Burrowing\" Invasion of the Cervix Represents a Separate Primary From the Concurrent Uterine Corpus Endometrial Endometrioid Adenocarcinoma: Histology, Immunohistochemistry, and Next-generation Sequencing Study of a Single Case.","authors":"Yan Li, Jackson Chen, Shuang Niu","doi":"10.1097/PGP.0000000000000990","DOIUrl":"10.1097/PGP.0000000000000990","url":null,"abstract":"<p><p>A small subset of endometrial endometrioid adenocarcinoma cases first reported in 2003, showed a distinct cervical component with a so-called \"burrowing\" invasion pattern. Initially, the cervical component was regarded as cervical involvement by the endometrial adenocarcinoma. However, a 2010 study argued that these cases actually might represent separate primary endometrial and cervical endometrioid adenocarcinomas. However, additional data on this topic are scarce. Here, we report a case of endometrioid adenocarcinoma with a \"burrowing\" cervical invasion that is morphologically distinct from the patient's endometrial endometrioid adenocarcinoma. By comparing the morphology, immunophenotype, and genetic profile obtained by next-generation sequencing, we demonstrated that the cervical and endometrial tumors were of 2 separate primaries. Our report adds additional data to this unique phenomenon, and will hopefully help to reignite interest in investigating this controversial topic.</p>","PeriodicalId":14001,"journal":{"name":"International Journal of Gynecological Pathology","volume":" ","pages":"271-274"},"PeriodicalIF":2.4,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71481324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PReferentially Expressed Antigen in MElanoma Expression in Uterine and Ovarian Carcinosarcomas.","authors":"Alaaeddin Alrohaibani, Yun Yu, Lina Gao, Kimberly M McLean, Jonathon Hetts, Ozlen Saglam","doi":"10.1097/PGP.0000000000000959","DOIUrl":"10.1097/PGP.0000000000000959","url":null,"abstract":"<p><p>Carcinosarcoma (CS) is an aggressive form of gynecologic malignancy that accounts for ~5% of carcinomas in the endometrium and ovaries. There has been no significant improvement in survival over the last decades despite additional treatment options. PReferentially Expressed Antigen in MElanoma (PRAME) is an immunotherapy target used for the treatment of several solid tumors. We explored the PRAME protein expression levels in ovarian and uterine CS (n = 29). The expression levels were recorded by H-score (percentage of positively stained cells multiplied by staining intensity) in carcinomatous and sarcomatous components separately and compared by paired t-test. The marker expression levels of ovarian and uterine CS were tested against each other in the CS group. Sarcoma-predominant samples (>50% of the sampled tissue) were compared with samples without predominant sarcomatous components by a 2-sample pooled t-test. In addition, high-grade carcinomatous components of CS samples were tested against low-grade endometrioid carcinoma (International Federation of Gynecology and Obstetrics grades 1 and 2; n = 13), and sarcomatous components against uterine leiomyosarcoma (n = 14). There was no significant difference between any subgroups except for sarcomatous elements of CS and leiomyosarcoma ( P < 0.001). A weak positive correlation was found between H-scores of carcinomatous and sarcomatous components ( P = 0.062, r = 0.36). In the ovarian CS group, there was a moderate inverse correlation between age and the mean H-score of the carcinomatous component ( r = -0.683, P = 0.02). Our results further support PRAME overexpression in gynecologic cancers, including CS with similar expression levels in epithelial and mesenchymal components. PRAME might have a role in epithelial-mesenchymal transition in this group of cancers.</p>","PeriodicalId":14001,"journal":{"name":"International Journal of Gynecological Pathology","volume":" ","pages":"284-289"},"PeriodicalIF":2.4,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138798932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ovarian Mesonephric-like Adenocarcinoma Recurring With a Rhabdomyosarcoma Component: A Case Report.","authors":"Akiko Yamamoto, Takeshi Nagai, Aoi Sukeda, Manami Kajiwara, Masaharu Fukunaga, Toru Sasaki, Yuta Kinoshita, Motoshige Hayashi, Shigehiro Hayashi, Masataka Ono, Masayuki Futagami, Hirotaka Nishi","doi":"10.1097/PGP.0000000000000991","DOIUrl":"10.1097/PGP.0000000000000991","url":null,"abstract":"<p><p>Mesonephric-like adenocarcinoma (MLA) has recently been described as a tumor of the endometrium or ovaries, which, morphologically and immunohistochemically, resembles mesonephric adenocarcinoma arising mostly in the uterine cervix. Herein, we report, to our knowledge, the first case of ovarian MLA that developed into an extremely rapidly growing recurrent mesonephric-like carcinosarcoma, as confirmed by a genomic profiling test. A 51-year-old woman underwent chemotherapy with complete debulking surgery for ovarian carcinoma. Pathologically, the patient was diagnosed with stage IVB ovarian MLA. Subsequent to 15 months of complete remission, an enhanced computed tomography scan revealed a solid tumor of 10 cm diameter in the abdominal cavity. Secondary surgery was terminated with a 2 cm 2 tumor biopsy specimen collection considering perioperative complications. Histologically, the tumor consisted of short spindle cells, and immunohistochemical staining revealed a rhabdomyosarcomatous profile without an epithelial component. Despite treatment for the sarcoma, she died 3 months after the detection of the tumor. The genomic profiling of the primary ovarian carcinoma and secondary resected tumor biopsy specimens revealed an identical KRAS mutation in both. Therefore, we concluded that the ovarian MLA recurred with a rhabdomyosarcoma component.</p>","PeriodicalId":14001,"journal":{"name":"International Journal of Gynecological Pathology","volume":" ","pages":"296-301"},"PeriodicalIF":2.4,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138798817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fibroepithelial Stromal Polyp of the Vulvovaginal Region as Part of the RB1 Family of Tumors: Friend or Foe?","authors":"Fleur Cordier, Nadine Van Roy, Bart Matthys, Pascale De Paepe, Koen Van de Vijver, Jo Van Dorpe, David Creytens","doi":"10.1097/PGP.0000000000000998","DOIUrl":"10.1097/PGP.0000000000000998","url":null,"abstract":"<p><p>Fibroepithelial stromal polyps (FSPs) are benign mesenchymal lesions occurring in the vulvovaginal region. Following the identification of loss of Retinoblastoma 1 (RB1) on immunohistochemical staining in routine practice, we stained a series of FSPs and performed additional fluorescence in situ hybridization (FISH) and copy number variation (CNV) sequencing to detect losses/deletions in the Retinoblastoma transcriptional corepressor 1 (RB1) gene. Fifteen FSP cases were stained for RB1, and subsequently, 9 cases were examined by FISH to detect a loss of RB1 (13q). Next, CNV sequencing was performed to assess genomic alterations. The mean age of the patients was 50 years. Loss of RB1 expression on immunohistochemistry was seen in 13 cases, and heterogeneous RB1 staining in the remaining 2 cases. FISH showed deletion of RB1 in all of the cases. CNV sequencing failed in almost all cases due to a low tumor content. Based on our findings, we hypothesize that FSPs are part of a spectrum of genetically related lesions, namely the 13q/RB1 family of tumors (which includes pleomorphic fibromas and spindle cell/pleomorphic lipomas). Due to the clinical, morphologic, and molecular overlap, we suggest that FSPs are pleomorphic fibromas occurring in the specialized stroma of the genital region.</p>","PeriodicalId":14001,"journal":{"name":"International Journal of Gynecological Pathology","volume":" ","pages":"215-220"},"PeriodicalIF":2.4,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71481325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"HER2-low and Overexpression in Mucinous Ovarian Cancer: Analysis of ASCO/CAP and ToGA Immunohistochemical Scoring.","authors":"Rachel Han, Ainhoa Madariaga, Eduardo Gonzalez-Ochoa, Adam C Smith, Lisa Wang, Stephanie Lheureux, Marjan Rouzbahman","doi":"10.1097/PGP.0000000000000972","DOIUrl":"10.1097/PGP.0000000000000972","url":null,"abstract":"<p><p>Mucinous ovarian carcinoma is an uncommon malignancy characterized by resistance to chemotherapy and poor survival in the metastatic setting. HER2 amplification is a frequent late event in carcinogenesis, yet the incidence of HER2-low in mucinous ovarian carcinoma is unknown. Further, the optimal method for determining overexpression in these tumors is not established. We sought to assess the ASCO/CAP and ToGA trial scoring methods for HER2 IHC with correlation to FISH, p53, and mismatch repair protein status and to determine the incidence of HER2-low in mucinous ovarian carcinoma. A total of 29 tumors from 23 patients were included. Immunohistochemistry for HER2, p53, MLH1, PMS2, MSH2, and MSH6 was performed. Scoring was performed according to the ASCO/CAP and ToGA trial criteria. HER2 FISH was performed and scored according to the ASCO/CAP criteria. The proportion of HER2-low, defined as 1+ or 2+ staining with negative FISH, was determined. Using ASCO/CAP, 26% demonstrated 3+ while 35% demonstrated 2+ staining. Using ToGA, 30% demonstrated 3+ while 57% demonstrated 2+ staining. By FISH, 26% were positive for HER2 amplification. Both systems captured all FISH-positive cases; the use of ASCO/CAP resulted in fewer equivocal and false-positive cases. Among HER2-negative cases, 88% were HER2-low. Aberrant p53 expression was detected in 55% of cases; mismatch repair deficiency was not identified in any cases. ASCO/CAP guidelines are accurate and resource-effective in determining HER2 overexpression in mucinous ovarian carcinoma. HER2-low is common in these tumors; further studies to determine the role of HER2-targeted therapy including antibody-drug conjugates are indicated.</p>","PeriodicalId":14001,"journal":{"name":"International Journal of Gynecological Pathology","volume":" ","pages":"275-283"},"PeriodicalIF":2.4,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140021717","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}