Archives of pathology & laboratory medicine最新文献

{"title":"Mesenchymal Neoplasms of the Pancreatobiliary Tract.","authors":"Diana Agostini-Vulaj","doi":"10.5858/arpa.2025-0508-RA","DOIUrl":"https://doi.org/10.5858/arpa.2025-0508-RA","url":null,"abstract":"<p><strong>Context.—: </strong>Mesenchymal neoplasms of the pancreatobiliary tract are extremely rare, with most representing secondary involvement or metastatic disease. A wide range of primary benign and malignant mesenchymal neoplasms can arise in the pancreatobiliary tract. This includes the newly proposed entity, sclerosing epithelioid neoplasm of the pancreas. Thus, appropriate classification and diagnosis are essential.</p><p><strong>Objective.—: </strong>To review the array of primary benign and malignant mesenchymal neoplasms arising in the pancreatobiliary tract, with discussion of clinicopathologic features, including morphology, immunohistochemistry, and molecular characteristics, as applicable for select tumors.</p><p><strong>Data sources.—: </strong>Literature review of published studies.</p><p><strong>Conclusions.—: </strong>When faced with a primary mesenchymal neoplasm of the pancreas, most are benign, most often representing a schwannoma, followed by inflammatory myofibroblastic tumor, and solitary fibrous tumor. If malignant, leiomyosarcoma has been the most frequently reported entity. Sclerosing epithelioid neoplasm may be considered in cases with distinct histologic features and appropriate diagnostic workup as described. In the gallbladder and biliary tract, the most common entities encountered include granular cell tumor, schwannoma, and inflammatory myofibroblastic tumor.</p>","PeriodicalId":93883,"journal":{"name":"Archives of pathology & laboratory medicine","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148957415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inflammatory Soft Tissue Tumors: A Wolf in Sheep's Clothing.","authors":"Douglas Rottmann, Kyle D Perry","doi":"10.5858/arpa.2025-0368-RA","DOIUrl":"https://doi.org/10.5858/arpa.2025-0368-RA","url":null,"abstract":"<p><strong>Context.—: </strong>The diagnosis of soft tissue tumors is becoming increasingly complex as the number of entities and associated ancillary studies continues to increase. Mesenchymal tumors with prominent associated inflammation are challenging, given that the pathologist might not consider soft tissue entities in the differential diagnosis. This review will cover selected inflammatory soft tissue tumors commonly encountered in surgical pathology practice or associated with recurrent diagnostic pitfalls, namely,inflammatory well-differentiated liposarcoma/atypical lipomatous tumor, angiomatoid fibrous histiocytoma, myxoinflammatory fibroblastic sarcoma, inflammatory myofibroblastic tumor, and mass-forming fibroinflammatory lesions, as well as key vascular tumors with associated inflammation.</p><p><strong>Objective.—: </strong>To review inflammatory soft tissue tumors most commonly encountered in surgical practice or prone to significant diagnostic challenges. This article will also cover relevant ancillary studies and provide a brief differential diagnosis.</p><p><strong>Data sources.—: </strong>Literature review through PubMed search.</p><p><strong>Conclusions.—: </strong>With advancements in musculoskeletal medicine leading to more targeted treatments, precise histologic classification is key to improving patient outcomes. This is particularly important for inflammatory soft tissue lesions, as some malignant conditions may be mistaken for reactive processes. Achieving an accurate diagnosis relies on identifying morphologic characteristics, considering the clinical presentation, and using appropriate ancillary studies.</p>","PeriodicalId":93883,"journal":{"name":"Archives of pathology & laboratory medicine","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148957405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Building Capacity for Breast Cancer Diagnosis: Evaluation of a Radiology-Pathology Project Extension for Community Health Outcomes (ECHO) in Nigeria.","authors":"Zainab Illonga, Oluwatosin Omoyiola, Omolade Betiku, Adeleye Omisore, Victoria L Mango, Tammy Huang, Cristina Olcese, Rivka Kahn, Ryan Fodero, Seyram Doe-Tetteh, Naqiya Rahil Choonawala, Elia J Mmbaga, Dianna L Ng, Marcia Edelweiss","doi":"10.5858/arpa.2026-0136-OA","DOIUrl":"https://doi.org/10.5858/arpa.2026-0136-OA","url":null,"abstract":"<p><strong>Context.—: </strong>The Breast Cancer Radiology-Pathology Project Extension for Community Health Outcomes (RAD-PATH ECHO), by Memorial Sloan Kettering Cancer Center and the African Research Group for Oncology, is an interactive, virtual program connecting radiologists and pathologists from North America and Nigeria and aims to address challenges in breast cancer diagnosis in low-resource settings.</p><p><strong>Objective.—: </strong>To evaluate the RAD-PATH ECHO program and its impact on participants.</p><p><strong>Design.—: </strong>The evaluation included a survey of participants to assess learning preferences, training needs, perceived barriers in breast cancer diagnosis, and the perceived impact of RAD-PATH ECHO on building local capacity. In addition, following each RAD-PATH ECHO session, participants received a free-text survey with the prompt \"What were the 3 main learning points of today's session?\"</p><p><strong>Results.—: </strong>Twenty-one participants responded to the online survey. Insufficient equipment (62%; 13 of 21) and poor communication between medical specialties (52%; 11 of 21) were identified as primary challenges in breast cancer diagnosis. Respondents preferred interactive case-based learning (81%; 17 of 21) and felt RAD-PATH ECHO improved their ability to manage patients (57%; 12 of 21). Recommendations for improvement included adding more institutions and increasing the number of sessions per year. Post-session surveys revealed the following 3 key themes: (1) Importance of communication to improve radiology-pathology diagnostic correlation; (2) transfer of diagnostic knowledge; and (3) guidance on biopsy procedure-related issues.</p><p><strong>Conclusions.—: </strong>RAD-PATH ECHO is beneficial for enhancing knowledge and promoting multidisciplinary discussion in Nigeria and can serve as a supplementary resource for practicing radiologists and pathologists. Future initiatives should focus on developing strategies to increase participation and disseminate the program.</p>","PeriodicalId":93883,"journal":{"name":"Archives of pathology & laboratory medicine","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148957433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mismatch Repair Deficiency in Upper Gastrointestinal and Pancreaticobiliary Cancers: Integrating Multimodal Molecular Data in Clinical Practice.","authors":"Sarah Davidson, Joanna A Gibson","doi":"10.5858/arpa.2025-0592-OA","DOIUrl":"https://doi.org/10.5858/arpa.2025-0592-OA","url":null,"abstract":"<p><strong>Context.—: </strong>Mismatch repair deficiency (MMRd) is a key diagnostic and predictive biomarker, yet its mechanisms in upper gastrointestinal (UGI) and pancreaticobiliary (PB) malignancies remain incompletely defined.</p><p><strong>Objective.—: </strong>To evaluate real-world clinical practices and multimodal molecular assessments of MMRd UGI and PB malignancies at a tertiary academic medical center.</p><p><strong>Design.—: </strong>We analyzed 91 MMRd UGI and PB cancers from 90 patients. MMRd immunohistochemistry (IHC) patterns and use of ancillary molecular tests (MSI-PCR, MLH1 promoter methylation, germline testing, and tumor next-generation sequencing [NGS]) were reviewed.</p><p><strong>Results.—: </strong>The most common primary sites were stomach (40 of 91; 44%), esophageal (15 of 91; 16%), and small bowel carcinoma (11 of 91; 12%), with pancreatic (8 of 91; 9%), biliary tract (7 of 91; 8%), and ampullary (4 of 91; 4%) carcinomas less frequent. Paired MLH1 of PMS2 loss was the predominant MMRd IHC pattern (71 of 91, 78%), followed by unusual patterns of loss (11 of 91, 12%), and paired MSH2 of MSH6 loss (9 of 91, 10%). Among the subset with MSI testing, MMRd by IHC and MSI were discordant in 16% (3 of 19) of cases. MLH1 promoter methylation was present in 80% (37 of 46) of the tested MLH1 of PMS2-deleted tumors. Lynch syndrome (LS) was identified in 17% (6 of 36) of patients with genetic testing. In addition, somatic MMR gene variants were identified in 43% (9 of 21) of tumors sequenced by NGS.</p><p><strong>Conclusions.—: </strong>MMRd in UGI and PB cancers arises from diverse mechanisms, including MLH1 promoter methylation, somatic MMR gene alterations, and LS. A multimodal approach integrating IHC, MSI-PCR, tumor NGS, and MLH1 promoter methylation is essential for accurate biomarker characterization and optimized LS screening.</p>","PeriodicalId":93883,"journal":{"name":"Archives of pathology & laboratory medicine","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148957377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Streamlining Urinary Tract Infection Evaluation in a Large Pediatric Hospital System: Feasibility of Reflex Urine Culture After Urinalysis With Microscopy.","authors":"Dan Wang, Xiaotian Zheng, David Gannon, Anne Hall, Ilka Warshawsky","doi":"10.5858/arpa.2025-0453-OA","DOIUrl":"https://doi.org/10.5858/arpa.2025-0453-OA","url":null,"abstract":"<p><strong>Context.—: </strong>Reflex urine culture testing can reduce unnecessary cultures, limit inappropriate antibiotic use for asymptomatic bacterial presence, and lower health care costs. In pediatrics, considerations include patient age, specimen collection method, and evidence-based urinalysis criteria to identify clinically significant urinary tract infections.</p><p><strong>Objective.—: </strong>To determine how many positive urine cultures would be missed if a reflex urine culture approach were applied in a large pediatric hospital system.</p><p><strong>Design.—: </strong>A retrospective review of pediatric urine samples collected for ∼10 months with concurrent urinalysis (chemical and microscopic) and urine culture results was performed. Urinalysis was considered positive if 1 or more of the following were present: leukocyte esterase, nitrite, more than 10 white blood cells per high-power field, or bacteria. Positive urinalysis results were compared with urine culture thresholds of 1000 colony-forming units per milliliter (CFU/mL) or greater; 10 000 CFU/mL or greater; and 50 000 CFU/mL or greater in catheter and nonsterile urine collections.</p><p><strong>Results.—: </strong>Of 6926 samples, 1520 (21.9%) were catheter collections and 5406 (78.1%) were nonsterile. Applying urine culture thresholds of 10 000 CFU/mL or greater and 50 000 CFU/mL or greater for catheter and nonsterile collections, respectively, a negative urinalysis finding demonstrated a high negative predictive value (≥96.6%). A reflex culture protocol would have eliminated 3652 of 6926 cultures (52.7%) and would have missed 71 of 6926 total samples (1.0%). Organisms other than Escherichia coli were more frequently isolated from cultures that were negative by urinalysis.</p><p><strong>Conclusions.—: </strong>Implementing reflex urine culture testing based on positive urinalysis results can help reduce unnecessary urine cultures in the pediatric population with a high negative predictive value.</p>","PeriodicalId":93883,"journal":{"name":"Archives of pathology & laboratory medicine","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148763057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experience of the United States-Canadian Mesothelioma Reference Panel 1985-2026: Historical Review and New Developments in Mesothelial Pathology.","authors":"Andrew Churg, Richard Attanoos, Mary Beth Beasley, Kelly Butnor, Lucian Chirieac, Sanja Dacic, Francoise Galateau-Salle, Elizabeth Pavlisko, Anja C Roden, Victor L Roggli, Thomas Sporn, Henry Tazelaar, William D Travis, Yin P Hung","doi":"10.5858/arpa.2026-0006-RA","DOIUrl":"https://doi.org/10.5858/arpa.2026-0006-RA","url":null,"abstract":"<p><strong>Context.—: </strong>The United States-Canadian Mesothelioma Reference Panel was established in 1985. Data on the first 200 cases were published in 1991.</p><p><strong>Objectives.—: </strong>To review what has changed in mesothelial pathology since the first Mesothelioma Panel article was published.</p><p><strong>Data sources.—: </strong>Cases referred to the United States-Canadian Mesothelioma Reference Panel and published literature.</p><p><strong>Conclusions.—: </strong>Panel accessions have reached 4000. The major problems for which the first 200 cases were referred were mesothelioma versus another tumor and mesothelioma versus a benign mesothelial proliferation, and these remain the most common issues that the panel adjudicates. In the 1990s the panel depended on histochemistry and a very limited set of immunohistochemical carcinoma markers, as well as electron microscopy, to separate mesotheliomas from other tumors; currently there is an overabundance of immunohistochemical markers for this purpose, only a few of which are really specific. In the 1990s the panel depended almost entirely on morphology to separate benign from malignant mesothelial processes, but the advent of genetic analysis has led to very reliable surrogate immunohistochemical and fluorescence in situ hybridization tests for this separation. New issues and entities that the panel briefly touched on (well-differentiated papillary mesothelial tumor) or did not deal with in the 1990s, including mesothelioma genetics, cytologic diagnosis of mesothelioma, mesothelioma in situ, and solid papillary mesothelial tumor, have been addressed by panel members and are reviewed here. Mesothelioma diagnostic pathology has undergone remarkable development during the past 40 years, such that most mesotheliomas can be readily diagnosed and separated from various mimics.</p>","PeriodicalId":93883,"journal":{"name":"Archives of pathology & laboratory medicine","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148763692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"From Residency to Practice: Overcoming Employment Obstacles for Non-US Citizen Pathologists in the United States.","authors":"Cindy B McCloskey, Mary P Berg, Julie Katz Karp, Amanda Lofgreen, Kristen Johnson, Diana Agostini-Vulaj, Stephanie Barak, Hailey Gosnell, Tiffany M Hebert, Barbara E C Knollmann-Ritschel, Balaram Puligandla, Kristie L White, Bronwyn H Bryant","doi":"10.5858/arpa.2025-0619-CP","DOIUrl":"https://doi.org/10.5858/arpa.2025-0619-CP","url":null,"abstract":"<p><strong>Context.—: </strong>Non-US citizen international medical graduates (IMGs) represent a significant minority of individuals filling pathology positions in the Main Residency Match and actively practicing as pathologists. Prior surveys have not allowed definitive conclusions about how the citizenship status impacts pathology job search experiences.</p><p><strong>Objective.—: </strong>To improve understanding of the possible barriers to non-US citizen IMGs entering the US job market.</p><p><strong>Design.—: </strong>The College of American Pathologists Graduate Medical Education Committee developed a survey to understand the impact of US versus non-US medical graduates and citizenship status on the job search experience. Pathologists who graduated from US pathology residency and/or fellowship training programs who have been in practice for 10 years or less were targeted. Multiple distribution channels were used.</p><p><strong>Results.—: </strong>Survey responses were received from 413 individuals. Significantly fewer non-US IMGs found their first non-fellowship position in the United States and many reported greater difficulty finding a position, with a longer job search. Non-US IMGs more frequently encountered bias during their job search, most often due to visa sponsorship. Both non-US IMGs and their employers found their experiences with the immigration system to be complicated, confusing, and financially challenging.</p><p><strong>Conclusions.—: </strong>The reported survey results suggest possible opportunities for improving how non-US citizen pathology residency graduates navigate the job market, how their potential employers approach hiring them, and how professional associations assist their non-US citizen members.</p>","PeriodicalId":93883,"journal":{"name":"Archives of pathology & laboratory medicine","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148690480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cellular Viability of Whole Blood Specimens Is a Sensitive Indicator of Transport Conditions.","authors":"Scott M Ennis, Yifei K Yang, Amir A Sadighi Akha, Attila Kumánovics","doi":"10.5858/arpa.2026-0046-OA","DOIUrl":"https://doi.org/10.5858/arpa.2026-0046-OA","url":null,"abstract":"<p><strong>Context.—: </strong>Transporting specimens can expose them to uncontrolled environmental factors. Whole blood viability is a commonly used preanalytic marker of quality for analysis of white blood cells.</p><p><strong>Objective.—: </strong>To evaluate whole blood viability as a marker for transportation and specimen integrity for lymphocyte subset evaluation.</p><p><strong>Design.—: </strong>More than 9000 whole blood specimens, transported during a 4-year period, and their lymphocyte subset evaluation results were analyzed retrospectively. Viability was measured by using Cellaca MX imaging cytometer, and lymphocyte and lymphocyte subset counts were determined with flow cytometry. Specimen cell viability results were stratified based on different transportation factors to discern their potential effects. Lymphocyte subset evaluation results from specimens with lower viability were compared with those from optimal viability specimens.</p><p><strong>Results.—: </strong>Cell viability of transported specimens exhibited seasonal variation, decreasing during the warm summer months (median, 77.0% versus 83.4% in other seasons). The decline in viability negatively correlated with ambient temperature during transportation (r = -0.7876). Longer transportation time (>60 hours) also caused a decrease in viability (median, 64.0%). While we observed a decrease in absolute cell counts for CD45+ lymphocytes, CD3+ T cells, CD8+ T cells, and CD19+ B cells in specimens with low viability (50%-80%), the differences were well within the assay's total allowable error.</p><p><strong>Conclusions.—: </strong>Control of preanalytic factors is critical for laboratory testing. Whole blood viability is a sensitive indicator of transport conditions and time, but it is not a specific predictor of quality for the main lymphocyte populations in cellular immunology testing.</p>","PeriodicalId":93883,"journal":{"name":"Archives of pathology & laboratory medicine","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148690408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Critical Limits and Clinical Recommendations for Notification of Life-Threatening Glucose Test Results in the 21st Century.","authors":"Gerald J Kost, Kami Osher, Kyle Cheng, Chloe Cota, Tarini Guru","doi":"10.5858/arpa.2025-0486-OA","DOIUrl":"https://doi.org/10.5858/arpa.2025-0486-OA","url":null,"abstract":"<p><strong>Context.—: </strong>Critical limits represent quantitative boundaries of life-threatening diagnostic results that demand urgent clinician notification and potentially, lifesaving intervention.</p><p><strong>Objectives.—: </strong>To document 35-year changes in glucose critical limits, characterize decision thresholds at independent and network hospitals, identify US geographic risk differences, report point-of-care testing results, and align critical notifications, pathophysiological risk, and consensus recommendations to improve outcomes.</p><p><strong>Design.—: </strong>We gathered critical limit notification lists from 417 hospitals comprising university, trauma, and heart centers, and network and community hospitals in all 50 states and Washington, District of Columbia, then extracted glucose critical limits for adults and newborns.</p><p><strong>Results.—: </strong>All hospitals listed low and high glucose critical limits. Between 1990 and 2025, low glucose critical limits increased significantly (P < .001) with medians of 45 (range, 30-70) versus 50 (range, 35-60) mg/dL, respectively. Histograms documented striking inconsistencies. Matched pairs (N = 73) of laboratory versus point-of-care low glucose critical limits at the same hospitals did not differ significantly. A US risk level map identified geographic discrepancies relative to the neuroglycopenic impaired awareness threshold of 54 mg/dL. There were statistically significant changes in newborn low and high distributions with 2025 medians of 40 (range, 20-55) and 200 (range, 120-500) mg/dL, respectively.</p><p><strong>Conclusions.—: </strong>An increased median low critical limit of 50 mg/dL does not match the 54 mg/dL threshold for neuroglycopenic loss of awareness that places patients at risk. The median high critical limit of 450 mg/dL at network hospitals decreases the risks of extreme hyperglycemia. The risk map revealed geographic inconsistencies, lack of harmonization, and poor alignment with consensus clinical recommendations.</p>","PeriodicalId":93883,"journal":{"name":"Archives of pathology & laboratory medicine","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148702720","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reevaluation of Human Epidermal Growth Factor Receptor 2 (HER2) Expression in Breast Cancer Samples Previously Scored as Immunohistochemistry 0 or 1+ to Characterize HER2-Ultralow Prevalence.","authors":"Savitri Krishnamurthy, Clara Lam, Dhanrajan Tiruchinapalli, Linlin Luo, Rosemary Taylor, Ehab ElGabry, Michele Sue-Ann Woo, Simon M Collin, Simone T Sredni, Stella Redpath","doi":"10.5858/arpa.2025-0579-OA","DOIUrl":"https://doi.org/10.5858/arpa.2025-0579-OA","url":null,"abstract":"<p><strong>Context.—: </strong>Prevalence data of human epidermal growth factor receptor 2 (HER2)-ultralow (immunohistochemistry [IHC] 0 with membrane staining in ≤10% of cells; HER2 IHC 0+) breast cancer are limited.</p><p><strong>Objective.—: </strong>To evaluate the proportion of HER2-ultralow among metastatic breast cancer samples originally scored HER2 IHC 0 (with or absent membrane staining) and 1+ and to evaluate interobserver concordance between pathologists' rescores and original scores.</p><p><strong>Design.—: </strong>Whole slide images (WSIs) from metastatic breast cancer biopsy specimens originally scored HER2 IHC 0 (with or absent membrane staining) and 1+ were rescored as HER2 IHC 0 absent membrane staining, IHC 0+ (with membrane staining), IHC 1+, or IHC 2+ by 3 pathologists. Each pathologist performed 2 blinded readings (washout period of ≥2 weeks).</p><p><strong>Results.—: </strong>Of the 246 IHC 0 WSIs, 78 (31.7%), 75 (30.5%), and 86 (35.0%) were rescored as HER2 IHC 0 absent membrane staining, 0+, and 1+, respectively. Of the 138 IHC 1+ WSIs, 3 (2.2%), 10 (7.2%), 117 (84.8%), and 6 (4.3%) were rescored as IHC 0 absent membrane staining, 0+, 1+, and 2+, respectively. Interobserver concordance was substantial (overall percentage agreement [OPA; 95% CI], 86.7% [82.9%-90.0%]; Cohen κ [95% CI], 0.781 [0.726-0.835]) to moderate (OPA [95% CI], 62.0% [59.9%-66.9%]; Cohen κ [95% CI], 0.441 [0.379-0.502]). Agreement between pathologists' consensus scores and original scores was moderate (OPA [95% CI], 72.1% [67.3%-76.5%]; Cohen κ [95% CI], 0.461 [0.381-0.541]).</p><p><strong>Conclusions.—: </strong>Scoring discrepancies highlight the potential need/benefits of training for evaluating HER2-low/HER2-ultralow cases in metastatic breast cancer, which could improve consistency in HER2 scoring by pathologists.</p>","PeriodicalId":93883,"journal":{"name":"Archives of pathology & laboratory medicine","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148671532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}