HistopathologyPub Date : 2025-02-20DOI: 10.1111/his.15428
Laëtitia Launet, Adrián Colomer, Andrés Mosquera-Zamudio, Carlos Monteagudo, Valery Naranjo
{"title":"The puzzling Spitz tumours: is artificial intelligence the key to their understanding?","authors":"Laëtitia Launet, Adrián Colomer, Andrés Mosquera-Zamudio, Carlos Monteagudo, Valery Naranjo","doi":"10.1111/his.15428","DOIUrl":"https://doi.org/10.1111/his.15428","url":null,"abstract":"<p><p>Since their first description in 1948, Spitz tumours remain one of the most challenging diagnostic entities in dermatopathology due to their complex histological features and ambiguous clinical behaviour. In recent years, artificial intelligence (AI) solutions have demonstrated significant potential across a wide range of medical applications, including computational pathology, for decision-making in diagnosis, along with promising advances in prognosis and tumour classification. However, the application of AI to Spitz tumours remains relatively underexplored, with few studies addressing this field. Yet in this evolving technological landscape, could AI provide the insights needed to help resolve the diagnostic uncertainties surrounding Spitz tumours? How could this technology be leveraged to bridge the gap between histopathological uncertainty and clinical accuracy? This review aims to provide an overview of the current state of AI applications in Spitz tumour analysis, identify existing research gaps, and propose future directions to optimize the use of AI in understanding and diagnosing these complex tumours.</p>","PeriodicalId":13219,"journal":{"name":"Histopathology","volume":" ","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143457863","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}
HistopathologyPub Date : 2025-02-20DOI: 10.1111/his.15434
Joseph S Durgin, Nicholas A Zoumberos, Taylor Novice, Douglas R Fullen, Alexandra C Hristov, Lori Lowe, Rajiv M Patel, Paul W Harms, Aleodor A Andea, Scott C Bresler
{"title":"Role of single-nucleotide pleomorphism microarray in the classification of BAP1-inactivated melanocytic tumours.","authors":"Joseph S Durgin, Nicholas A Zoumberos, Taylor Novice, Douglas R Fullen, Alexandra C Hristov, Lori Lowe, Rajiv M Patel, Paul W Harms, Aleodor A Andea, Scott C Bresler","doi":"10.1111/his.15434","DOIUrl":"https://doi.org/10.1111/his.15434","url":null,"abstract":"<p><strong>Aims: </strong>BAP1-inactivated melanocytic tumours (BIMTs) occur sporadically and in association with a familial tumour predisposition syndrome involving germline mutations in the BRCA1-associated protein-1 (BAP1) gene. Here we report the clinical features, histopathologic findings, and chromosomal copy number data of 19 BAP1-inactivated melanocytomas (BIMs) and compare their features to those of five BAP1-inactivated melanomas.</p><p><strong>Methods: </strong>We retrospectively searched the Department of Pathology archives and EMERSE (Electronic Medical Record Search Engine) for BIMTs that had undergone single-nucleotide polymorphism (SNP) microarray testing. Clinical history/follow-up data, detailed histopathologic features, and SNP microarray results were recorded.</p><p><strong>Results: </strong>Overall, four patients (4/13) with BIMs and available clinical history had features suspicious for a germline BAP1 aberration. In BIMs (19 cases), the BAP1-inactivated component showed variable cytologic features, including epithelioid (predominant), rhabdoid, plasmacytoid, and nevoid morphologies. Sentinel lymph node biopsy was negative in all (6/6) patients in which this procedure was performed. No patient diagnosed with a BIM with available clinical follow-up (18/19; mean 38 months) experienced an adverse event. While the histologic appearances of the five melanomas varied, one case resembled a BIM. The median mitotic count was 1/mm<sup>2</sup> (range 0-6 mm<sup>2</sup>) in BIMs compared to 3/mm<sup>2</sup> (range 1-4/mm<sup>2</sup>) in melanomas (P = 0.04). The median number of copy number alterations (CNAs) was two (range 0-6) in indolent cases versus seven (range 6-10) in melanomas (P = 0.0005). The most common molecular aberration after loss of 3p21 was heterozygous loss of the CDKN2A locus, which unlike homozygous loss has not been associated with melanoma.</p><p><strong>Conclusion: </strong>While most BIMs appear to have a favourable prognosis, even those with multiple CNAs, they deserve careful integration of all clinical and pathologic findings. Although not fully diagnostic, a mitotic count of ≥3/mm<sup>2</sup> and ≥6 CNAs in the appropriate context is supportive of a diagnosis of BAP1-inactivated melanoma.</p>","PeriodicalId":13219,"journal":{"name":"Histopathology","volume":" ","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143457860","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":"Kikuchi-Fujimoto disease: investigating comprehensive clinicopathological features and risk factors for recurrence.","authors":"Midori Filiz Nishimura, Chikako Sakao, Yuka Kurokawa, Yoshito Nishimura, Asami Nishikori, Hidetaka Yamamoto, Yasuharu Sato","doi":"10.1111/his.15427","DOIUrl":"https://doi.org/10.1111/his.15427","url":null,"abstract":"<p><strong>Aims: </strong>Kikuchi-Fujimoto disease (KFD) is a rare disease that typically manifests with fever and cervical lymphadenopathy. Little is known about the risk factors associated with recurrence and their correlation with clinicopathologic features.</p><p><strong>Methods and results: </strong>We analysed 112 patients with KFD, predominantly female (61/112, 54.5%), with an average age of 29.4 years. The incidence was higher in males up to the age of 20 and higher in females from their 30s onwards. Of the 70 patients with follow-up data, 23% experienced recurrence. Recurrence was associated with lower C4 levels (P = 0.038) and higher antinuclear antibody (ANA) rates (P = 0.007) compared to transient disease. The mean duration of symptoms was 71.5 days. Lymph node histology in 98 cases (excluding 14 needle biopsy specimens) was classified into three patterns: proliferative (n = 75, 77%), necrotizing (n = 22, 22%), and xanthomatous (n = 1, 1%). The necrotizing pattern associated with significantly enlarged lymph nodes (P = 0.047) and a longer symptom duration (P = 0.009) than the proliferating pattern. The number of CD4-positive lymphocytes was significantly lower in the necrotizing type than in the proliferative type (P < 0.001).</p><p><strong>Conclusion: </strong>These results indicated that low C4 levels and positive ANA were associated with KFD recurrence. Although the aetiology of KFD remains elusive, given that some cases develop autoimmune disease, the results suggest that patients with recurrent KFD represent an intermediate status between those with transient KFD and those with overt autoimmune disease. The comprehensive clinicopathological findings of this study may be useful for elucidating its pathogenesis and predicting the clinical course.</p>","PeriodicalId":13219,"journal":{"name":"Histopathology","volume":" ","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143440779","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}
HistopathologyPub Date : 2025-02-17DOI: 10.1111/his.15429
Pu Ni, Noam Harpaz, Abeer Altahrawi, Qingqing Liu
{"title":"Diagnostic and prognostic significance of Crohn's disease-like pathology in surgically diverted recta of patients with ulcerative colitis.","authors":"Pu Ni, Noam Harpaz, Abeer Altahrawi, Qingqing Liu","doi":"10.1111/his.15429","DOIUrl":"https://doi.org/10.1111/his.15429","url":null,"abstract":"<p><strong>Aims: </strong>Diversion colitis (DC), commonly seen in surgically diverted bowel, can exhibit features resembling Crohn's disease (CD) even in patients with an established ulcerative colitis (UC). The superposition of DC on inflammatory bowel disease (IBD) complicates pathological assessment and potentially alters the diagnosis from UC to CD. We investigated the diagnostic and prognostic significance of CD-like histological features in DC.</p><p><strong>Methods and results: </strong>We examined diverted recta from 202 patients (84 females, 118 males; median age = 37, range = 7-79) who underwent post-diversion proctectomy from 2018 to 2023. Pre-operative diagnoses included UC (n = 162), CD (n = 20), indeterminate IBD (IIBD, n = 11) and non-IBD (n = 9). We evaluated granulomas and deep mucosal ulcers and scored transmural chronic inflammation (TCI) on a four-tier scale. Patients were followed for 8-73 months for development of CD-like complications, e.g. small bowel enteritis, strictures or fistulas.</p><p><strong>Conclusions: </strong>TCI was present in all groups but was less frequent in non-IBD (P = 0.015), with median scores similar for UC and CD (median = 1), higher in the IIBD (median = 2) and lower in the non-IBD (median = 0, P = 0.084). TCI scores did not correlate with the development of CD-like complications (CDLC) and therefore did not have prognostic significance. Conversely, granulomas and fissuring ulcers were significantly more common in CD than UC and IIBD and absent in non-IBD (P < 0.0001 and P = 0.0009, respectively). These features correlated with higher TCI scores (P = 0.023 and P = 0.009, respectively). In summary, granulomas and fissuring mucosal ulcers in diverted recta favours a diagnosis of CD, while TCI alone does not justify altering a diagnosis of UC.</p>","PeriodicalId":13219,"journal":{"name":"Histopathology","volume":" ","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143440776","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}
HistopathologyPub Date : 2025-02-17DOI: 10.1111/his.15433
Newton A C S Wong, Maurice B Loughrey, Adrian C Bateman, Manuel Rodriguez-Justo, Neil A Shepherd
{"title":"Vascular intrusion is a mimic of true vascular invasion in large bowel adenomatous polyps.","authors":"Newton A C S Wong, Maurice B Loughrey, Adrian C Bateman, Manuel Rodriguez-Justo, Neil A Shepherd","doi":"10.1111/his.15433","DOIUrl":"https://doi.org/10.1111/his.15433","url":null,"abstract":"<p><strong>Aims: </strong>'Vascular intrusion' is a proposed but poorly recognised phenomenon of colorectal adenomas whereby dysplastic epithelium is forced into blood vessels. This study aimed to validate its existence and to characterise histological features that distinguish it from true vascular invasion.</p><p><strong>Methods and results: </strong>Three gastrointestinal pathologists independently assessed 38 colorectal polyps showing possible vascular intrusion as two cohorts. After the cohort A (15 cases) assessment, the pathologists met to decide upon diagnostic criteria and consensus diagnoses. They met again after the cohort B (23 cases) assessment to establish final consensus diagnoses. Histological features found to favour vascular intrusion were: absence of adenocarcinoma; presence of adjacent epithelial misplacement; low-grade cytology; crush artefact; and presence of lamina propria among the intravascular glands. The proportion of cases where all three pathologists independently agreed upon diagnoses of vascular intrusion versus vascular invasion increased from 53% for cohort A to 74% for cohort B. However, while there were final consensus diagnoses of vascular intrusion and vascular invasion for 21 and seven cases, respectively, the assessors were unable to agree upon either diagnosis for 10 cases. Follow-up of 17 patients who had undergone polyp resection > 3 years previously (including eight with consensus diagnoses of vascular intrusion) did not demonstrate recurrent or metastatic colorectal carcinoma.</p><p><strong>Conclusions: </strong>Vascular intrusion may be caused by forcing of adenoma into vessels as part of epithelial misplacement or during resection or laboratory processing of the polyp. Histological features of the intravascular glands and surrounding adenoma help to distinguish this benign/artefactual phenomenon from true vascular invasion.</p>","PeriodicalId":13219,"journal":{"name":"Histopathology","volume":" ","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143440796","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":"Challenges of a tailored immunohistochemistry algorithm for uterine leiomyosarcoma: an integrated analysis of leiomyomas with bizarre nuclei and fumarate hydratase (FH) deficiency.","authors":"Catarina Alves-Vale, Nathalène Truffaux, Valérie Velasco, Rihab Azmani, Melissa Alamé, Flora Rebier, Laetitia Mayeur, Yanick Leger, Isabelle Hostein, Isabelle Soubeyran, Larry Blanchard, Estelle Marion, Quitterie Fontanges, François Le Loarer, Gerlinde Averous, Catherine Genestie, Laurent Arnould, Mojgan Devouassoux-Shisheboran, Sabrina Croce","doi":"10.1111/his.15420","DOIUrl":"https://doi.org/10.1111/his.15420","url":null,"abstract":"<p><strong>Aims: </strong>Leiomyomas (LM) are the most common uterine mesenchymal neoplasms and encompass a variety of histological subtypes. Bizarre nuclei are described in both leiomyomas with bizarre nuclei (LM-BN) and fumarate hydratase-deficient leiomyomas (FH-LM), which raise diagnostic concerns regarding leiomyosarcoma (LMS). Recently, an immunohistochemical algorithm to support the diagnosis of LMS based on the genomic landscape of these neoplasms was proposed. This study aimed to evaluate the algorithm's accuracy in distinguishing LM-BN and FH-LM from LMS.</p><p><strong>Methods and results: </strong>We collected 68 LM (29 LM-BN, 30 FH-LM, and 9 LM) and 9 LMS, along with clinicopathological and molecular data. An immunohistochemical panel comprising p53, Rb, PTEN, ATRX, DAXX, and MDM2 was applied. Nine cases were non-interpretable due to fixation issues. The algorithm demonstrated 100% accuracy for LM without bizarre nuclei (9/9) and for nonmyxoid LMS (5/5). Notably, 28.6% (14/49) of LM-BN and FH-LM exhibited at least two abnormalities, leading to potential misclassification as LMS. However, their clinical course, morphology, and genomic profile supported a benign diagnosis. Frequent alterations included Rb (20/49; 40.8%) and p53 (19/49; 38.8%), particularly in bizarre cells, while no abnormal staining was observed for ATRX, DAXX, or MDM2.</p><p><strong>Conclusion: </strong>The proposed algorithm has limitations in differentiating LMS from LM-BN and FH-LM, misclassifying 28.6% of the latter. Accurate interpretation requires proper internal controls, particularly for markers whose loss of expression favours malignancy. Morphology remains central for diagnosis, although integration of molecular data may provide additional insights for a definitive classification in challenging cases.</p>","PeriodicalId":13219,"journal":{"name":"Histopathology","volume":" ","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143440773","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}
HistopathologyPub Date : 2025-02-17DOI: 10.1111/his.15432
Markus Plass, Gheorghe-Emilian Olteanu, Sanja Dacic, Izidor Kern, Martin Zacharias, Helmut Popper, Junya Fukuoka, Sosuke Ishijima, Michaela Kargl, Christoph Murauer, Lipika Kalson, Luka Brcic
{"title":"Comparative performance of PD-L1 scoring by pathologists and AI algorithms.","authors":"Markus Plass, Gheorghe-Emilian Olteanu, Sanja Dacic, Izidor Kern, Martin Zacharias, Helmut Popper, Junya Fukuoka, Sosuke Ishijima, Michaela Kargl, Christoph Murauer, Lipika Kalson, Luka Brcic","doi":"10.1111/his.15432","DOIUrl":"https://doi.org/10.1111/his.15432","url":null,"abstract":"<p><strong>Aim: </strong>This study evaluates the comparative effectiveness of pathologists versus artificial intelligence (AI) algorithms in scoring PD-L1 expression in non-small cell lung carcinoma (NSCLC). Immune-checkpoint inhibitors have revolutionized NSCLC treatment, with PD-L1 expression, measured as the tumour proportion score (TPS), serving as a critical predictive biomarker for therapeutic response.</p><p><strong>Methods and results: </strong>In our analysis, 51 SP263-stained NSCLC cases were scored by six pathologists using light microscopy and whole-slide images (WSI), alongside evaluations by two commercially available software tools: uPath software (Roche) and the PD-L1 Lung Cancer TME application (Visiopharm). The study examined intra- and interobserver agreement among pathologists at TPS cutoffs of 1% and 50%, revealing moderate interobserver agreement (Fleiss' kappa 0.558) for TPS <1% and almost perfect agreement (Fleiss' kappa 0.873) for TPS ≥50%. Intraobserver consistency was high, with Cohen's kappa ranging from 0.726 to 1.0. Comparisons between the AI algorithms and the median pathologist scores showed fair agreement for uPath (Fleiss' kappa 0.354) and substantial agreement for the Visiopharm application (Fleiss' kappa 0.672) at the 50% TPS cutoff.</p><p><strong>Conclusion: </strong>These results indicate that while there is strong interobserver concordance among pathologists at higher TPS levels, the performance of AI algorithms is less consistent. The study underscores the need for further refinement of AI tools to match the reliability of expert human evaluation, particularly in critical clinical decision-making contexts.</p>","PeriodicalId":13219,"journal":{"name":"Histopathology","volume":" ","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143440774","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}
HistopathologyPub Date : 2025-02-12DOI: 10.1111/his.15430
Andrew M Leader, Jason L Hornick, William J Anderson
{"title":"An unusual mimic of sarcoma: HPV-associated squamous cell carcinoma of the anorectum with extensive sarcomatoid differentiation","authors":"Andrew M Leader, Jason L Hornick, William J Anderson","doi":"10.1111/his.15430","DOIUrl":"10.1111/his.15430","url":null,"abstract":"","PeriodicalId":13219,"journal":{"name":"Histopathology","volume":"86 6","pages":"1010-1012"},"PeriodicalIF":3.9,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143407280","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}
HistopathologyPub Date : 2025-02-12DOI: 10.1111/his.15425
Emma J Norton, Adrian C Bateman
{"title":"Pitfalls during histological assessment in locally resected pT1 colorectal cancer.","authors":"Emma J Norton, Adrian C Bateman","doi":"10.1111/his.15425","DOIUrl":"https://doi.org/10.1111/his.15425","url":null,"abstract":"<p><p>Colorectal cancer (CRC) is a common malignancy worldwide, and the stage of the tumour is closely related to clinical outcome. Bowel cancer screening programmes have resulted in the identification of colorectal cancer at earlier stages. Approximately 10% of patients with the earliest stage of CRC (i.e. pT1) will possess regional lymph node metastases (LNM). Therefore, if these patients have initially been treated by local resection (e.g. polypectomy), this subgroup will require surgical resection. Identification of pathological risk factors for LNM within locally resected pT1 CRC is a very important process during the histological assessment of these lesions. This paper describes the most commonly encountered and clinically significant difficulties in the histological assessment of these cases. These pitfalls are illustrated using four examples of locally resected pT1 CRC that were received by our department during routine diagnostic practice.</p>","PeriodicalId":13219,"journal":{"name":"Histopathology","volume":" ","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143407282","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}
HistopathologyPub Date : 2025-02-12DOI: 10.1111/his.15426
Andrew H S Lee, Emad A Rakha, Zsolt Hodi, Areeg Abbas, Ian O Ellis, Stephen Chan
{"title":"Retesting of oestrogen receptor, progesterone receptor and HER2 status of invasive carcinoma of the breast after neoadjuvant chemotherapy.","authors":"Andrew H S Lee, Emad A Rakha, Zsolt Hodi, Areeg Abbas, Ian O Ellis, Stephen Chan","doi":"10.1111/his.15426","DOIUrl":"https://doi.org/10.1111/his.15426","url":null,"abstract":"<p><strong>Aims: </strong>There is no consensus on whether oestrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) status should be assessed after neoadjuvant chemotherapy. This study assessed the frequency of changes in ER, PR and HER2 status after neoadjuvant chemotherapy.</p><p><strong>Methods and results: </strong>Of 353 patients who had neoadjuvant chemotherapy and anti-HER2 treatment, receptors were assessed in 185 residual carcinomas. Eight per cent of carcinomas that were ER-negative in the core biopsy were ER-positive in the excision compared with 1.5% of controls. All were HER2-positive in the core biopsy and 23% were HER2-negative in the excision compared with 0% of controls. Controls were cases tested in the core biopsy and subsequent surgical resection with no neoadjuvant treatment. Of 589 patients who had neoadjuvant chemotherapy alone, receptors were assessed in 495 residual carcinomas. Six per cent of carcinomas that were ER-negative in the core biopsy were ER-positive in the excision (mainly ER-low positive) compared with 1.5% of controls. All were HER2-negative in the core biopsy and 6% were HER2-positive in the excision (mainly immunohistochemistry score 2+ and HER2 gene amplified) compared with 2% of controls.</p><p><strong>Conclusions: </strong>Negative to positive changes in receptor status after neoadjuvant chemotherapy are infrequent and the positive result in the excision is often weakly positive. These results imply that repeat assessment after neoadjuvant chemotherapy and surgery could influence the subsequent treatment in a small proportion of patients.</p>","PeriodicalId":13219,"journal":{"name":"Histopathology","volume":" ","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143407284","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}