International Journal of Gynecological Pathology最新文献

{"title":"Validation of Tumor Budding as a Prognostic Factor in Ovarian Clear Cell Carcinoma Using an Independent Cohort.","authors":"Lawrence H Lin, Lina Irshaid, Ursula A Matulonis, David L Kolin","doi":"10.1097/PGP.0000000000001099","DOIUrl":"https://doi.org/10.1097/PGP.0000000000001099","url":null,"abstract":"<p><p>Ovarian clear cell carcinoma (OCCC) is an endometriosis-related neoplasm, in which traditional histologic grading does not show prognostic significance. Tumor budding was associated with poorer outcomes in OCCC in previous studies. We aimed to evaluate the prognostic significance of tumor budding in OCCC in an independent cohort. Seventy patients diagnosed with OCCC were retrospectively identified. Slides from primary ovarian resections were reviewed by 2 pathologists blinded to outcomes. Tumor budding was defined as single or clusters of <5 tumor cells in peritumoral and/or intratumoral nonhyalinized stroma. Most patients were diagnosed at an early stage (stage I: 69%; II: 20%; III: 10%; IV: 1%). Twenty-one patients experienced recurrences (30%) and 2 progressive disease (3%). At the last follow-up, 52 patients had no evidence of disease, 6 were alive with disease, and 12 died of disease. The median follow-up time was 66.7 mo. Tumor budding was identified in 41 cases (59%) with a kappa coefficient of 0.60. On univariate analysis, tumor budding (P=0.022) and stage (P=0.0005) were associated with shorter progression-free survival (PFS), but only stage was independently associated with shorter PFS on multivariate analysis (P=0.003). Higher stage was the only variable associated with shorter overall survival (P=0.037). Tumor budding was associated with higher stage (P=0.039), absence of endometriosis (P=0.042) and adenofibroma (P=0.046), tumor-associated inflammation (P=0.002), and higher mitotic activity (P=0.022). There was no association between tumor budding and molecular characteristics in 32 cases with somatic tumor sequencing. Tumor budding was not independently associated with worse outcomes in this cohort of OCCC, although it was significantly associated with specific clinicopathologic features, including higher stage. Stage was the only independent variable predictive of poorer survival, which appears to drive the prognostic significance of tumor budding.</p>","PeriodicalId":14001,"journal":{"name":"International Journal of Gynecological Pathology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143046501","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":"Mesonephric and Mesonephric-like Adenocarcinomas of the Gynecologic Tract: A Case Series and a Review of the Literature.","authors":"Lisa Liu, Morgan Storino, Yiting Stefanie Chen, Allison Walker, Deline Da Costa, Shivani Shukla, Ashley Graul","doi":"10.1097/PGP.0000000000001097","DOIUrl":"https://doi.org/10.1097/PGP.0000000000001097","url":null,"abstract":"<p><p>We sought to present and describe all cases of mesonephric adenocarcinoma (MNAC) and mesonephric-like adenocarcinomas (MLAs) at our institution. These cancers are rare, morphologically similar tumors of the female reproductive tract. In this case series, we present 13 new cases of MNAC/MLA that were identified at St. Luke's University Health Network from 2016 to 2024. Demographics, clinical characteristics, and pathologic findings were collected from chart review. There were 6 uterine, 5 ovarian, and 2 cervical MNAC/MLAs. At presentation, more than half of the patients presented at early stages with 7, 2, 3, and 1 diagnosed at stages I, II, III, and IV, respectively. All patients underwent upfront surgical resection and were recommended adjuvant therapy. One patient declined adjuvant treatment. At the time of writing, 9 of 13 patients have completed treatment and have no evidence of disease, 1 is alive with disease, 1 is currently undergoing treatment, and 2 died of disease. Median overall survival (OS) was 15 mo (95% CI: 2.2-27.8 mo). Current literature regarding MNACs/MLAs suggests an overall poor prognosis, with the majority presenting at advanced stages. This case series describes patients diagnosed with early-stage disease and reports on their histopathology, treatment regimens, and clinical outcomes. The majority of these patients are without recurrence after upfront treatment. Continued surveillance of these patients to determine long-term outcomes is necessary to further elucidate overall prognosis.</p>","PeriodicalId":14001,"journal":{"name":"International Journal of Gynecological Pathology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143046249","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":"TP53 Mutations and PD-L1 Amplification in Vulvar Adenocarcinoma of the Intestinal Type: Insights From Whole Exome Sequencing of 2 Cases.","authors":"Erisa Fujii, Mayumi Kobayashi Kato, Hanako Ono, Maiko Yamaguchi, Daiki Higuchi, Takafumi Koyama, Masaaki Komatsu, Ryuji Hamamoto, Mitsuya Ishikawa, Tomoyasu Kato, Takashi Kohno, Kouya Shiraishi, Hiroshi Yoshida","doi":"10.1097/PGP.0000000000001093","DOIUrl":"https://doi.org/10.1097/PGP.0000000000001093","url":null,"abstract":"<p><p>Vulvar adenocarcinoma of the intestinal type (VAIt) is a rare subtype of primary vulvar carcinoma, with ∼30 cases documented in the English literature. This study presents 2 new cases of HPV-independent VAIt with lymph node metastasis and discusses their clinical presentation, histopathologic features, and whole exome sequencing (WES) analysis. Both cases exhibited histologic features consistent with VAIt, including tubular, papillary, and mucinous carcinoma components. Immunohistochemical analysis showed p16 patchy staining, CDX2, CK20, and SATB2 positivity, while being negative for ER, PAX8, and CK7. WES revealed pathogenic TP53 mutations in both cases, accompanied by distinct additional mutations (GRIN2A and KDM6A in Case #1; CHD4 in Case #2). Common copy number alterations (CNAs) included TP53 loss of heterozygosity and CD274/PD-L1 amplification. However, other CNAs varied between the cases. Immunohistochemistry for p53 suggests the presence of both wild-type and mutant subclones, indicating that TP53 abnormalities may be acquired during tumor progression. Both tumors showed mutational signatures SBS1 and SBS5, associated with aging and DNA damage. Our findings deepen the understanding of the genetic events involved in the tumorigenesis of HPV-independent VAIt. Given the TP53 abnormalities and CD274/PD-L1 amplification, emerging p53-based therapies and immune checkpoint inhibitors may represent potential treatment targets. While these findings contribute to the understanding of VAIt tumorigenesis, further research is required to validate these observations in a larger cohort.</p>","PeriodicalId":14001,"journal":{"name":"International Journal of Gynecological Pathology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143046475","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":"Testosterone-induced Seminal Vesicle-like Differentiation in Cervical Mesonephric Duct Remnants in a Female to Male Transgender Patient.","authors":"Gayanie Ratnayake, Karen L Talia, Mila Volchek, W Glenn McCluggage","doi":"10.1097/PGP.0000000000001091","DOIUrl":"10.1097/PGP.0000000000001091","url":null,"abstract":"<p><p>Pure ductal-type mesonephric remnants in the uterine cervix are rare. We report an unusual case in a 31-yr-old of cervical mesonephric remnants of predominantly ductal type exhibiting seminal vesicle-like differentiation in a female-to-male transgender patient receiving long-term testosterone therapy. To the best of our knowledge, this phenomenon has not been previously reported. The impact of testosterone on the female genital tract is likely to be encountered more frequently due to increasing rates of gender-affirming surgery, including long-term androgen use. Awareness of the morphologic features is important as such changes may be misinterpreted as premalignant or malignant lesions. In reporting this unusual case, we briefly review lesions derived from cervical mesonephric remnants and testosterone-associated changes in the female genital tract.</p>","PeriodicalId":14001,"journal":{"name":"International Journal of Gynecological Pathology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143046362","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":"Case Report: ESR1::CITED2 Fusion in a Malignant Uterine Tumor Resembling Ovarian Sex Cord Tumor.","authors":"Ferheen Abbasi, Marisa R Nucci, Ben Doron, Rachel Ruskin, Jeremy Chien, Jaclyn C Watkins, Anthony N Karnezis","doi":"10.1097/PGP.0000000000001092","DOIUrl":"https://doi.org/10.1097/PGP.0000000000001092","url":null,"abstract":"<p><p>Uterine tumor resembling ovarian sex cord tumor (UTROSCT) is a rare, typically benign uterine tumor occurring over a wide age range (mean 52.4 yr). UTROSCTs often harbor translocations between ESR1 and nuclear receptor coactivators NCOA1-NCOA3. Here, we present a 21-yr-old woman with a 16 cm complex uterine mass on CT. Grossly, the tumor had an infiltrative appearance. Histologically, it consisted of mild to moderately atypical, spindled cells with ovoid nuclei, growing in fascicles and cords within fibrous to myxohyaline stroma, with tongue-like infiltration of the myometrium. Immunohistochemically, tumor cells were positive for AE1/AE3, ER, PR, vimentin, WT-1, and CD56, and negative for inhibin, calretinin, SMA, desmin, and CD10. Whole exome and whole transcriptome sequencing identified a pathogenic ESR1::CITED2 fusion. The tumor recurred twice (15 and 21 mo after initial surgery) in the abdomen and pelvis. Taken together, the findings suggest this tumor may represent a malignant UTROSCT variant with a novel translocation.</p>","PeriodicalId":14001,"journal":{"name":"International Journal of Gynecological Pathology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143046073","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":"Verruciform Acanthotic Vulvar Intraepithelial Neoplasia Harbors Recurrent Genomic Alterations Found in HPV-independent Squamous Cell Carcinoma.","authors":"Eleanor Cook, Claire J H Kramer, Tjalling Bosse, Mariette van Poelgeest, Koen Van de Vijver, Marisa R Nucci, Carlos Parra-Herran","doi":"10.1097/PGP.0000000000001094","DOIUrl":"https://doi.org/10.1097/PGP.0000000000001094","url":null,"abstract":"<p><p>The term verruciform acanthotic vulvar intraepithelial neoplasia (vaVIN) was coined to describe HPV-independent p53-wildtype lesions with characteristic clinicopathologic characteristics and association with vulvar squamous cell carcinoma (vSCC). We aimed to expand on the molecular landscape of vaVIN using comprehensive sequencing and copy number variation profiling. vaVIN diagnosis in institutional cases was confirmed by a second review, plus negative p16 and wildtype p53 by immunohistochemistry. Multigene next-generation sequencing and shallow-whole genome sequencing were used to survey for single-nucleotide variants (SNV), copy number alterations, and structural variants. Targeted TERT promoter sequencing was also carried out. Nineteen patients with vaVIN were included; 4 had concurrent vSCC. The median patient age was 74 (range 56-90) years. Genomic aberrations were noted in 18 cases (95%) as follows: PIK3CA in 10 (53%), CDKN2A in 7 (37%), HRAS in 6 (32%), FAT1 and NOTCH1-2 in 5 each (26%), TSC2 in 2 (11%), and PTEN, ARID2, and KRAS in 1 (5%) each. TERT promoter variants were detected in 11 of 13 cases successfully tested (85%). Five vaVINs harbored a TP53 variant but showed wild-type p53 immunohistochemical expression. In one of these, the concurrent carcinoma showed abnormal p53 and biallelic TP53 mutations. Out of 15 patients with follow-up (mean: 20, range: 2-50 mo), vaVIN persistence/recurrence was seen in 8 (53%), and subsequent vSCC in 2 (13%). At the last encounter, 3 (20%) patients had persistent disease and 1 (7%) died of vSCC. vaVIN is characterized by a wider molecular spectrum, beyond known alterations in PIK3CA, HRAS, and ARID2, to include TERT promoter, CDKN2A, FAT1, and NOTCH1-2, which are characteristic of HPV-independent vSCC. vaVIN can occur with concurrent or subsequent carcinoma, sometimes with fatal outcomes. These findings support the concept of vaVIN as a neoplastic process within the family of HPV-independent vulvar neoplasia.</p>","PeriodicalId":14001,"journal":{"name":"International Journal of Gynecological Pathology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143046575","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":"Morphologic Correlations With Homologous Recombination Deficiency in High-grade Serous Carcinomas.","authors":"Udita Chapagain, Julia B Huecker, Lulu Sun","doi":"10.1097/PGP.0000000000001090","DOIUrl":"https://doi.org/10.1097/PGP.0000000000001090","url":null,"abstract":"<p><p>High-grade serous carcinomas (HGSCs) with homologous recombination deficiency (HRD) respond favorably to platinum therapy and poly ADP ribose polymerase (PARP) inhibitors. Mutations in BRCA1 and BRCA2 commonly cause HRD and have been associated with Solid, pseudoEndometrioid, and Transitional-like (SET-like) histology. Mutations in other homologous recombination repair (HRR) genes as well as epigenetic changes can also result in HRD; however, morphologic correlates have not been well-explored in these cases. We hypothesized that HGSCs with HRD, regardless of the etiology, are associated with specific morphologic features. Forty-three cases of HGSC with genomic profiling, which included HRR gene mutation analysis and HRD score, were evaluated. The morphologic patterns, degree of nuclear atypia, necrosis, mitotic index, and tumor-infiltrating lymphocytes (TILs) were determined. The results showed that HRD-high status was significantly associated with the presence of BRCA1/2 mutation, SET-like morphology, geographic necrosis, and severe nuclear atypia. Additional HRR pathway genes with oncogenic mutations identified included ATM, BRIP1, BLM, FANCC, CDK12, CHEK2, RAD51C, and RAD51D. Almost one-third of HRD-high tumors did not have mutations in any HRR pathway genes identified. In conclusion, HGSC with HRD, regardless of BRCA1/2-status, was associated with SET-like morphology and more severe nuclear atypia. Identifying and reporting these patterns of tumor morphology can prompt genomic profiling with prognostic, therapeutic, and genetic counseling implications.</p>","PeriodicalId":14001,"journal":{"name":"International Journal of Gynecological Pathology","volume":" ","pages":""},"PeriodicalIF":1.6,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143046288","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":"β-catenin, PAX2, and PTEN Aberrancy Across the Spectrum of Endometrioid Ovarian Lesions.","authors":"Maria M Del Mundo, Mitzi Aguilar, Hao Chen, Shuang Niu, Subhransu S Sahoo, Sambit Roy, Wenxin Zheng, Elena Lucas, Diego H Castrillon","doi":"10.1097/PGP.0000000000001046","DOIUrl":"10.1097/PGP.0000000000001046","url":null,"abstract":"<p><p>Endometriosis is a common condition, with the ovary being the most common anatomic site. Endometriosis-particularly in the ovary-is associated with a risk of malignant progression, with a histologic spectrum of lesions from benign to malignant. Recently, a panel of 3 markers consisting of β-catenin, PAX2, and PTEN has been described as a potentially useful diagnostic adjunct in the diagnosis of intrauterine endometrioid neoplasia, where aberrancy for one or more of the markers is strongly associated with neoplasia. Here, we applied the panel to ovarian endometrioid lesions, including endometriosis, endometriosis with flat cytologic atypia, endometrioid borderline tumors, and endometrioid adenocarcinoma (n=85 cases in total). The incidence of aberrancy for the 3 markers increased along this putative neoplastic spectrum, arguing for a role of each of the markers in the neoplastic transformation of ovarian endometriosis. Just 1/32 (3%) of cases of nonatypical endometriosis was marker-aberrant, and this case was aberrant only for PAX2. One of 5 cases (20%) of endometriosis with atypia was marker-aberrant (both PAX2 and PTEN), supporting prior findings that some cases of flat atypia may represent bona fide precursor lesions. Of 19 endometrioid borderline tumors, 10 (53%) were aberrant for one or more markers, with PAX2 being the most frequently aberrant. Of 29 endometrioid adenocarcinomas, 28 (96.6%) were aberrant for at least 1 marker, with PAX2 again the most frequently aberrant. Patterns of aberrancy were well-preserved in areas of nonatypical endometriosis adjacent to borderline tumor or adenocarcinoma, supporting a biological origin in a common marker-aberrant precursor. The findings show that the biomarker panel could be of some diagnostic utility in the characterization of ovarian endometrioid neoplasia, such as in the diagnosis of endometrioid borderline tumor, distinguishing endometrioid from nonendometrioid lesions, or in identifying other types of early precursors at a higher risk of malignant transformation.</p>","PeriodicalId":14001,"journal":{"name":"International Journal of Gynecological Pathology","volume":" ","pages":"79-87"},"PeriodicalIF":1.6,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11627306/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141792468","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":"Human Papilloma Virus-Independent/p53abnormal Keratinizing Squamous Cell Carcinoma of the Uterine Cervix Associated With Uterine Prolapse.","authors":"Lars-Christian Horn, Christine E Brambs, Bahriye Aktas, Astrid Dannenmann, Jens Einenkel, Michael Höckel, Irene Krücken, Sabine Taubenheim, Gero Teichmann, Ulrike Obeck, Mathias Stiller, Anne Kathrin Höhn","doi":"10.1097/PGP.0000000000001040","DOIUrl":"10.1097/PGP.0000000000001040","url":null,"abstract":"<p><p>Knowledge about the morphologic and molecular characteristics of cervical squamous cell carcinomas (CSCCs) associated with uterine prolapse is very limited. Detailed histopathological and immunohistochemical (p16, p53, and cytokeratin 17), as well as molecular evaluation for human papillomavirus (HPV)-DNA and p53-mutational analyses in 4 consecutive CSCCs associated with uterine prolapse with definition of a hitherto not well-described HPV-independent/p53abnormal precursor lesion (HPV-independent cervical intraepithelial neoplasia [CIN; differentiated CIN]) and molecular tumorigenetic pathway. Cases diagnosed within 7 years with a mean age of 75 (range: 69-83) years and a mean tumor size of 7.3 cm (range: 5.2-9.4 cm). All patients presented with locally advanced disease, and 1 woman died of the disease within 4, and another within 14 months of follow-up. All CSCCs and their adjacent precursor lesions were negative for p16, with aberrant p53-expression and diffuse and strong staining for cytokeratin 17. Both the CSCCs and their precursors were negative for HPV-DNA but harbored a TP53 mutation. The precursor lesions were characterized by epithelial thickening with superficial keratinization, and the presence of basal and parabasal keratinocytes with mitotic figures beyond the basal layer, thus showing features similar to those seen in differentiated types of vulvar intraepithelial lesions (vulvar intraepithelial neoplasia [VIN] syn. HPV-independent/p53abn VIN), suggesting the terminology of differentiated CIN or HPV-independent/p53abn CIN. An HPV-independent pathogenetic pathway with a p53-alteration was identified for these cases. CSCC associated with uterine prolapse represents HPV-independent tumors harboring a TP53 mutation. For the first time, a precursor lesion of HPV-independent CSCC of the uterine cervix is described with a differentiated VIN-like morphology, and a separate tumorigenic pathway defined.</p>","PeriodicalId":14001,"journal":{"name":"International Journal of Gynecological Pathology","volume":" ","pages":"2-14"},"PeriodicalIF":1.6,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141498002","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":"Napsin A Immunoreactivity in \"Hobnail\" Epithelium in Benign Endometrial and Endocervical Polyps.","authors":"Maysa Al-Hussaini, Karen L Talia, W Glenn McCluggage","doi":"10.1097/PGP.0000000000001037","DOIUrl":"10.1097/PGP.0000000000001037","url":null,"abstract":"<p><p>Endometrial and endocervical polyps not uncommonly exhibit focal benign \"hobnail\" change/metaplasia within the glandular epithelium, sometimes in association with inflammation or infarction. In most cases, this is readily recognized as benign but occasionally, especially in endometrial polyps, this change prompts consideration of a premalignant or malignant lesion, including early serous or clear cell carcinoma. Herein we highlight the previously unreported phenomenon of positive staining of this hobnail epithelium with Napsin A which has the potential to exacerbate concern for clear cell carcinoma. Endometrial (n = 22) and endocervical (n = 17) polyps showing hobnail change were stained with Napsin A. Six cases were positive (4 of 22 endometrial and 2 of 17 endocervical polyps). In all cases, Napsin A positivity was confined to the hobnail epithelium. The hobnail epithelium was positive with estrogen receptor and hepatocyte nuclear factor 1- beta and exhibited wild-type immunoreactivity with p53 in all cases where these markers were performed. In addition, in 2 of 3 uterine adenosarcomas with focal hobnail change the epithelium was Napsin A positive. Pathologists should be aware that Napsin A may be expressed in benign/reactive hobnail epithelium in endometrial and endocervical polyps and should not consider positivity with this marker as a diagnostic of clear cell carcinoma.</p>","PeriodicalId":14001,"journal":{"name":"International Journal of Gynecological Pathology","volume":" ","pages":"31-36"},"PeriodicalIF":1.6,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141087388","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}