Histopathology最新文献

{"title":"Histological and molecular characterization of lateral extension in papillary urothelial carcinoma: implications for classification and management.","authors":"Richard R Pacheco, Dylan J Peterson, Alan Thong, Eugene Shkolyar, Joseph C Liao, Guolan Lu, Kris B Prado, Fei Dong, Emily Chan","doi":"10.1111/his.70306","DOIUrl":"https://doi.org/10.1111/his.70306","url":null,"abstract":"<p><strong>Introduction: </strong>Lateral extension (LE) in urinary bladder papillary urothelial carcinoma (PUC) refers to the phenomenon where atypical urothelium is seen extending laterally in a flat configuration from the base of the papillary tumour. LE is recognized but poorly defined, resulting in inconsistent diagnoses and interpretations amongst pathologists, ranging from atypia to carcinoma in situ (CIS). Herein, we aim to better characterize LE in high-grade PUC, utilizing en bloc transurethral resection specimens.</p><p><strong>Methods: </strong>We reviewed 37 en bloc specimens from 25 patients and performed comprehensive morphological, molecular and immunohistochemical characterization of PUC and LE components.</p><p><strong>Results: </strong>Three morphological patterns were seen: no LE (n = 24), LE with lower-grade cytomorphology compared to adjacent PUC (lower-grade LE, n = 10), and LE with cytomorphology similar to adjacent PUC (higher-grade LE, n = 3). Mean LE length was 4.7 mm (range 1.5-10.8 mm). LE extended to mucosal margins in 12/13 (92%). Differential next-generation sequencing was performed on paired PUC and adjacent LE components in 11/13 tumours with LE. In 9/11 (82%), LE and PUC showed at least a subset of shared pathogenic/likely pathogenic alterations, supporting clonality between the two components; in five tumours, there were additional alterations specific to PUC, with and without LE-specific alterations. Immunohistochemical staining for CK20 and p53 showed LE with abnormal CK20 in all 11/11 tumours and aberrant p53 in 3/11 (27%). PUC and LE showed concordant p53 staining patterns in 10/11 (91%) and CK20 in only 6/11 (55%) specimens.</p><p><strong>Conclusion: </strong>We find that LE can extend at least 1 cm from the base of PUC, suggesting consideration for wider resection margins if complete surgical resection is desired. Additionally, LE is clonally related to PUC in most cases, albeit with heterogeneous relationships, as evidenced by both molecular and immunohistochemical findings. Notably, LE can show immunohistochemical findings similar to those commonly reported for CIS. Recognition of LE may improve diagnostic consistency and reduce overdiagnosis of CIS in the setting of prior papillary tumours.</p>","PeriodicalId":13219,"journal":{"name":"Histopathology","volume":" ","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149297147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PLAG1-rearranged paediatric fibromyxoid tumour: clinicopathological, molecular and epigenetic analysis of 10 cases supporting a morphological spectrum with lipoblastoma.","authors":"Faizan Malik, Selene C Koo, Quynh T Tran, Carina A Dehner, Robert E Ruiz, Meera Hameed, Anthony Arnoldo, Robert Siddaway, Brent A Orr, Rose Chami","doi":"10.1111/his.70308","DOIUrl":"https://doi.org/10.1111/his.70308","url":null,"abstract":"<p><strong>Aim: </strong>Paediatric PLAG1-rearranged fibromyxoid tumour (P-FMT) is an emerging soft-tissue neoplasm characterized by predominantly fibromyxoid morphology, minimal to absent adipocytic differentiation and consistent CD34 and desmin positivity. It is debated whether P-FMT represents a distinct entity or a morphological variant of lipoblastoma. We aim to better characterize P-FMT and assess its relationship with lipoblastoma.</p><p><strong>Methods and results: </strong>We assembled the largest cohort of P-FMT (n = 10) and performed comprehensive clinicopathological, molecular and epigenetic characterization. The cohort comprised five males and five females, aged 3 months to 10 years (median 4 years), with tumours arising in the extremities, trunk and neck. Histologically, all were well-demarcated lesions with bland fibroblastic spindle cells in collagenous to myxoid stroma; two cases focally contained mature adipocytes. All tumours expressed CD34 and desmin. PLAG1 rearrangements were confirmed by fluorescence in situ hybridization or molecular sequencing, with fusion partners identified as COL1A2 (n = 3), MEG3 (n = 2), BOC (n = 1), YWHAZ (n = 1), EEF1A1 (n = 1) and CHCHD7 (n = 1). DNA methylation profiling demonstrated that all P-FMTs grouped with lipoblastoma on hierarchical clustering and dimensionality reduction analysis and segregated from other mesenchymal tumours. Copy number profiles showed statistically significant chromosome 8 gain in both P-FMT and lipoblastoma. All cases with follow-up (median 22 months) demonstrated benign behaviour without recurrence.</p><p><strong>Conclusions: </strong>Our findings of morphological resemblance to fibroblastic lipoblastoma and multiple similarities to classic lipoblastoma, including identical immunophenotype, PLAG1 rearrangements with overlapping partners, common epigenetic signature and uniformly benign behaviour, support classification of P-FMT as a fibroblastic or minimally adipocytic subtype within the lipoblastoma spectrum, rather than a distinct entity.</p>","PeriodicalId":13219,"journal":{"name":"Histopathology","volume":" ","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149286676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Metastatic EWSR1::NFATC1 vascular neoplasm without sarcomatous transformation.","authors":"Yi-Ming Chang, Jia-Bin Liao, Wan-Shan Li, Hsuan-Ying Huang","doi":"10.1111/his.70310","DOIUrl":"https://doi.org/10.1111/his.70310","url":null,"abstract":"","PeriodicalId":13219,"journal":{"name":"Histopathology","volume":" ","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149266581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lipidic obstruction of sinusoids (LOS): a potentially serious complication of steatotic liver disease.","authors":"Katharina Endhardt, Juliane Friemel, Anne-Laure Leblond, Daniela Lenggenhager, Beat Müllhaupt, Rainer Grobholz, Achim Weber","doi":"10.1111/his.70309","DOIUrl":"https://doi.org/10.1111/his.70309","url":null,"abstract":"<p><strong>Introduction: </strong>During routine examination of specimens from patients with steatotic liver disease (SLD), we repeatedly observed a peculiar phenomenon characterized by obstruction of the hepatic sinusoids by lipid vacuoles (lipidic obstruction of sinusoids, LOS). These changes were reminiscent of pseudopeliotic steatosis (PPS), a complication following liver transplantation (LT), but notably occurred outside this context. The aim of our study was to identify diagnostic indicators for LOS and to determine its clinical significance.</p><p><strong>Methods: </strong>Liver specimens routinely sent to our institute between 2019 and 2024 with SLD were examined for LOS. The extracellular nature of the fat and the compression of the sinusoids were demonstrated by ancillary stains (Gomori, CD68, collagen IV). The extent of the LOS was quantified by measuring the area and maximum diameter of fat lakes. The clinical course of patients with LOS was retrospectively evaluated and correlated with the histological findings.</p><p><strong>Results: </strong>LOS was observed in eight patients, ranging from focal to very extensive extracellular fat. The diagnosis was based on routine histology, supplemented by collagen IV stain highlighting double contours of sinusoids. The morphological findings suggested that lipidic obstruction of the hepatic sinusoids was a key pathophysiological factor. LOS was associated with liver necrosis and activation of macrophages. Patients with LOS exhibited a variable clinical course, ranging from subclinical to severe, including LT or even death. The extent of fat lakes correlated with the severity of the clinical course.</p><p><strong>Conclusions: </strong>We suggest the term LOS for a particular pattern of liver damage that can occur in SLD outside the transplantation setting and may lead to impaired hepatic blood flow. LOS is associated with a variable clinical presentation, ranging from subclinical to fatal. Clinicians and pathologists should be aware of this complication of SLD, which is diagnosed by liver histology.</p>","PeriodicalId":13219,"journal":{"name":"Histopathology","volume":" ","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149286727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identification and relevance of inter-tumour heterogeneity in hepatocellular adenoma according to subtypes and the context.","authors":"Paulette Bioulac-Sage, Alberto Quaglia, Peter Schirmacher, Alphonse Charbel, Uta Drebber, Nyun Young Park, Taek Chung, Beate Katharina Straub, Brigitte Le Bail, Christine Sempoux, Charles Balabaud","doi":"10.1111/his.70298","DOIUrl":"https://doi.org/10.1111/his.70298","url":null,"abstract":"<p><strong>Introduction: </strong>Different molecular subtypes of hepatocellular adenoma (HCA) can occur at the same time within the same patient, defining inter-tumour heterogeneity (ITH). We describe a series of HCA-ITH cases, most identified in Bordeaux with additional cases contributed by other international centres.</p><p><strong>Methods: </strong>ITH-HCA cases were subtyped by immunohistochemistry, confirmed by molecular analysis in most cases. The resulting diagnoses were HNF1A-HCA (H-HCA), inflammatory HCA (IHCA), b-catenin-mutated HCA (b-HCA) involving exon 3 or 7/8, b-catenin-mutated IHCA (b-IHCA) involving exon 3 or 7/8, sonic hedgehog HCA (sh-HCA) and unclassified HCA (UHCA).</p><p><strong>Results: </strong>We identified 26 patients with ITH-HCA including 17 women; none had underlying liver disease, whereas most men did (8/9). The largest subgroup comprised 22 patients with IHCA combined with another subtype: H-HCA (five patients); H-HCA and b-IHCA-exon 3 borderline (one patient); b-IHCA-exon 3 (six patients); b-HCA and b-IHCA exon 3 (four patients); b-IHCA-exon7/8 (two patients); sh-HCA (three patients); UHCA (one patient). The remaining four patients had sh-HCA combined with UHCA (one patient) or b-IHCA ex3 (one patient), and 2 patients with HNF1A adenomatoses, one with malignant transformation, the other associated with a b-IHCA exon3 progressed to HCC. The largest nodule was a 13 cm IHCA. One of the sh-HCA presented with bleeding.</p><p><strong>Conclusion: </strong>ITH-HCA covers the whole spectrum of the HCA classification. It is rare but poses significant clinical challenges, particularly in terms of identifying those lesions at risk of malignant transformation (b-HCA or b-IHCA exon 3) or bleeding (sh-HCA). Referral to a special tertiary centre is recommended.</p>","PeriodicalId":13219,"journal":{"name":"Histopathology","volume":" ","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149238274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Grading colorectal adenocarcinoma: interobserver agreement between American Joint Committee on Cancer and World Health Organization criteria and revisiting diagnostic challenges.","authors":"Dipti M Karamchandani, Maurice B Loughrey, Reetesh K Pai, Christophe Rosty, Kelsey McHugh, Brian Cox, Rish K Pai","doi":"10.1111/his.70304","DOIUrl":"https://doi.org/10.1111/his.70304","url":null,"abstract":"<p><strong>Aim: </strong>The current American Joint Committee on Cancer (AJCC8) manual grades colorectal adenocarcinoma (CRC) based on the percentage of gland formation. The World Health Organization 5th ed (WHO5) and 6th ed (WHO6) grade based on the least differentiated component; WHO6 specifies a minimum 0.196 mm² area of the least-differentiated component away from the invasive front to merit a high-grade diagnosis. We studied the interobserver agreement and challenges among pathologists when grading CRC using the above grading systems.</p><p><strong>Methods and results: </strong>Five gastrointestinal pathologists reviewed 100 scanned CRC slides and graded each slide per the provided criteria in (a) WHO5, (b) WHO6, (c) AJCC8 and (d) their clinical practice. A post-survey questionnaire was also provided. The Fleiss multirater kappa among the five reviewers was similar using WHO6 (0.730, P < 0.001) and two-tiered (low vs. high) AJCC8 (0.731, P < 0.001) and was higher than WHO5 (0.655, P < 0.001) grading criteria; the agreement was substantial for all 3 grading systems. Significantly more tumours were called high-grade when using WHO6 (average: 34.4 cases) and WHO5 (average: 33.6 cases) as compared to AJCC8 (average: 11.8 cases) grading criteria (P < 0.01). All reviewers were unanimous in handling certain scenarios (e.g. discounting invasive front tumour buds with WHO grading), but were discordant on certain scenarios (e.g. assessment of stroma-rich areas).</p><p><strong>Conclusions: </strong>While inter-observer agreement improved with WHO6 versus WHO5, the persistent upgrading of tumours using the WHO scheme may affect treatment algorithms. Synchronization of grading criteria with validation in prospective studies with clinical outcomes is crucial.</p>","PeriodicalId":13219,"journal":{"name":"Histopathology","volume":" ","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149238235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hybrid lesions of hepatocellular adenoma and focal nodular hyperplasia: a clinicopathological and molecular study of two cases.","authors":"Yoh Zen, Peter Schirmacher","doi":"10.1111/his.70305","DOIUrl":"https://doi.org/10.1111/his.70305","url":null,"abstract":"<p><strong>Aims: </strong>Hybrid lesions containing distinct components of hepatocellular adenoma (HCA) and focal nodular hyperplasia (FNH) within a single nodule are exceptionally rare. This study aimed to investigate the biological nature of these unusual lesions.</p><p><strong>Methods and results: </strong>The two cases identified to date were examined by histopathological, immunohistochemical and targeted next-generation sequencing analyses. In case 1, the hybrid tumour (6.0 cm) consisted of approximately equal proportions of HNF1α-inactivated HCA and FNH, which were intimately admixed but remained histologically distinct. In case 2, the tumour (9.5 cm) consisted predominantly of HNF1α-inactivated HCA but contained a small peripheral nodule of FNH, resulting in a nodule-in-nodule appearance. The HCA components in both cases showed loss of FABP1 expression, whereas the FNH components retained FABP1 expression and showed a map-like pattern of glutamine synthetase expression. Next-generation sequencing in case 1 demonstrated that the mutations were not shared between the HCA and FNH components, with HNF1A and FLT1 mutations identified only in the HCA component. In case 2, the same HNF1A splice-site mutation was identified in both the HCA and FNH components, but was also present in the non-neoplastic gallbladder, confirming its germline origin. The HCA component, but not the FNH component, additionally harboured somatic mutations in ATM and FAT4.</p><p><strong>Conclusion: </strong>HCA, particularly the HNF1α-inactivated subtype, rarely coexists with FNH. The distinct molecular and immunohistochemical profiles of the two components support a collision mechanism, indicating that the FNH component represents a separate non-neoplastic lesion and arguing against one component arising from the other.</p>","PeriodicalId":13219,"journal":{"name":"Histopathology","volume":" ","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149227702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pathological assessment of neoadjuvant-treated melanoma specimens: a historical overview, lessons learned along the way and the road ahead.","authors":"Robert Rawson, Elizabeth M Burton, Michael T Tetzlaff","doi":"10.1111/his.70281","DOIUrl":"https://doi.org/10.1111/his.70281","url":null,"abstract":"<p><p>Neoadjuvant therapy has been recently established as the standard of care in surgically resectable stage III melanoma. Insofar as the extent of tumour response correlates with metrics of patient survival, this underscores the critical ongoing need for rigorous and reproducible approaches to pathological response assessment following surgery. In the current review, we provide a historical overview of early trials assessing safety and efficacy of neoadjuvant targeted and immune therapy, and we summarize the earliest and revised recommendations for pathological response assessment of treated melanoma specimens. Moreover, we highlight that not only the extent of response but also the composition of that response correlates with recurrence-free survival in these high-risk patients.</p>","PeriodicalId":13219,"journal":{"name":"Histopathology","volume":" ","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149220164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of the morphological, immunophenotypical and cytogenetic features of high-grade B-cell lymphoma with 11q aberration.","authors":"Zhihui Wang, Yi Liu, Jinghan Wang, Liming Xu, Han Zhang, Dan Li, Bo Wang, Lijun Wang, Zhaoming Wang, Wei Wang, L Jeffrey Medeiros, Fang Yu","doi":"10.1111/his.70303","DOIUrl":"https://doi.org/10.1111/his.70303","url":null,"abstract":"<p><strong>Aims: </strong>High-grade B-cell lymphoma with 11q aberration is a rare neoplasm of mature B-cell lineage, and large-scale clinicopathological studies of this disease remain scarce. To bridge this research gap, we conducted a retrospective analysis of HGBCL with 11q aberration, aiming to elucidate its pathogenesis, clinicopathological features and molecular profiles.</p><p><strong>Methods and results: </strong>By reviewing our hospital's case database from 2021 to 2025, we retrospectively screened 92 cases of high-grade or diffuse large B-cell lymphoma that had 11q fluorescence in situ hybridization (FISH) testing. Among them, 27 cases were confirmed to harbour 11q aberration and were enrolled in the present study. This cohort consisted of 24 males and 3 females with a median age of 61 years (range, 6-85). Eighteen (67%) patients presented with extranodal disease and nine (33%) had nodal disease. The gastrointestinal tract was the most commonly involved extranodal site (13 patients); two of these patients had concurrent lymph node involvement in the head and neck. Fourteen (52%) patients had advanced Ann Arbor stage (III, IV) disease. Eight (30%) patients had a history of immunocompromise including HIV infection, liver or kidney transplantation and other malignant tumours. The bone marrow was negative for lymphoma at initial diagnosis in all 21 patients assessed. Histologically, 20 (74%) cases had Burkitt-like or blastoid morphology and seven (26%) cases showed diffuse large B-cell-like morphology. Most cases (96%, 26/27) had a germinal centre B-cell immunophenotype. c-MYC was positive in all 26 tested cases and BCL2 was negative in 24 of 27 (89%) of cases. Mutational analysis was performed in 14 cases and potential driver mutations were identified in all involving 44 genes. The most frequently affected genes included TP53, IGLL5, DDX3X, BTG2, FOXO1, HIST1H1E and MYC. Following therapy, 24 patients achieved complete remission and disease-free survival. The prognosis was not related to the morphological features, Ann Arbor stage, co-occurrence of MYC aberrations or the chemotherapy regimens.</p><p><strong>Conclusions: </strong>High-grade B-cell lymphoma with 11q aberration may occur across all ages and confers a favourable prognosis. These tumours manifest morphological heterogeneity, and most cases display a Burkitt lymphoma-like immunophenotype characterized by CD10 positivity and BCL2 negativity. The most frequently mutated genes in our cohort are TP53, IGLL5, DDX3X, BTG2, FOXO1, HIST1H1E and MYC.</p>","PeriodicalId":13219,"journal":{"name":"Histopathology","volume":" ","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149220197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Alveolar soft part sarcoma of the female genital tract: a clinicopathological and molecular genetic study of 26 cases.","authors":"Lu Zhao, Fengyi Zhang, Tangchen Yin, Meng Sun, I Weng Lao, Shaoxian Tang, Qianming Bai, Wentao Yang, Xiaoyan Zhou, Lin Yu, Jian Wang","doi":"10.1111/his.70302","DOIUrl":"https://doi.org/10.1111/his.70302","url":null,"abstract":"<p><strong>Aims: </strong>Occurrence of alveolar soft part sarcoma (ASPS) in the female genital tract is extremely rare. We report 26 cases of ASPS arising in the female genital tract to further characterize its clinicopathological and molecular features, differential diagnosis and biological behaviour.</p><p><strong>Methods and results: </strong>Twenty-six cases of ASPS in the female genital tract were retrieved from our pathology archives. Patient age ranged from 11 to 69 years (median = 30 years). Tumours involved the uterus (n = 22), vagina (n = 3), and broad ligament (n = 1), with a median size of 3.3 cm (1.5-8.5 cm). Histologically, the tumours were predominantly composed of large epithelioid or round cells with abundant eosinophilic-to-clear cytoplasm, round nuclei and prominent nucleoli. Architecturally, tumour cells were arranged mostly in diffuse sheets or solid nests, while classic pseudoalveolar structures were rarely observed. All tumours showed strong TFE3 nuclear expression (100%), with variable immunoreactivity for ER (10/11, 90.9%) and PR (9/9, 100%). Twenty-one tested tumours demonstrated TFE3 rearrangement or ASPSCR1::TFE3 fusion by fluorescence in situ hybridization or targeted RNA sequencing. Among 21 patients' available follow-up data (range, 17-151 months; median, 30 months), 2 of 3 vaginal ASPS patients developed disease progression (1 local recurrence, 1 lung metastasis), whereas all 18 patients with uterine ASPS (range = 17-151 months; median = 30.5 months) remained disease-free.</p><p><strong>Conclusions: </strong>Female genital tract ASPS most commonly affects the uterus of young women. Uterine ASPS may have a relatively favourable prognosis. Distinguishing ASPS from its morphological mimickers, especially perivascular epithelioid cell tumour (PEComa), is of clinical importance to avoid inappropriate treatment and inaccurate prognosis assessment.</p>","PeriodicalId":13219,"journal":{"name":"Histopathology","volume":" ","pages":""},"PeriodicalIF":3.8,"publicationDate":"2026-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149165339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}