Applied immunohistochemistry & molecular morphology : AIMM最新文献

{"title":"TROP2, Cyclin D1, and Ki-67 as Prognostic Markers of Aggressive Pituitary Adenoma.","authors":"Aziza E Abdelrahman, Eman E Fayed, Hassan Abaza, Mohammad A Soliman, Ebtisam R Qasem, Moamna M Fahmy, Ahmed I Khalil, Safaa A Ahmed","doi":"10.1097/PAI.0000000000001336","DOIUrl":"10.1097/PAI.0000000000001336","url":null,"abstract":"<p><p>Pituitary adenomas have highly variable biological behavior, and reliable biomarkers are needed to distinguish indolent from aggressive tumors. This study evaluates the expression of TROP2, Cyclin D1, and Ki-67 as prognostic factors in pituitary adenomas. Fifty surgically resected pituitary adenomas were analyzed retrospectively. Immunohistochemical staining for TROP2, Cyclin D1, and Ki-67 was assessed and correlated with clinicopathological variables. The Logistic regression, Kaplan-Meier, and Cox regression analyses were performed to evaluate their prognostic value for recurrence and RFS. High Ki-67 expression (≥3%), Cyclin D1 overexpression, and TROP2 overexpression were identified in 42%, 60%, and 56% of cases, respectively. All 3 biomarkers were significantly associated with larger tumor size, invasiveness, higher Knosp and Hardy classifications, tumor recurrence, and shorter RFS. In multivariate analysis, Cyclin D1 and TROP2 remained independent predictors of RFS, while invasiveness was an independent predictor of tumor recurrence. Conclusion: Ki-67, Cyclin D1, and TROP2 are closely associated with aggressive clinicopathological features in pituitary adenomas. Among these markers, Cyclin D1 and TROP2 were the strongest independent predictors of recurrence-free survival. These findings support integrating these biomarkers into prognostic assessment models to refine postoperative follow-up protocols and identify patients at increased risk of recurrence.</p>","PeriodicalId":520562,"journal":{"name":"Applied immunohistochemistry & molecular morphology : AIMM","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2026-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148612249","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":"A High-Grade CD34-Positive Spindle Cell Sarcoma of the Palm Revealing an Unexpected TPM3::NTRK1 Fusion: A Diagnostic Pitfall With Major Therapeutic Implications.","authors":"Ayoub Nahal, Mahmoud El Kaissi, Suzan A Mbaideen, Lana Dabaan, Mohamed A Mashhour","doi":"10.1097/PAI.0000000000001346","DOIUrl":"https://doi.org/10.1097/PAI.0000000000001346","url":null,"abstract":"<p><p>NTRK-rearranged spindle cell neoplasms are increasingly recognized soft-tissue sarcomas that can closely mimic other CD34-positive spindle cell tumors, particularly dermatofibrosarcoma protuberans (DFSP) and solitary fibrous tumor (SFT). Failure to recognize this entity has important diagnostic and therapeutic consequences. We report a 17-year-old male with a rapidly enlarging palmar mass who initially underwent tumor excision abroad, where the lesion was diagnosed as synovial sarcoma. Upon presentation to our center with rapid local recurrence, the original pathology was reviewed and reinterpreted as fibrosarcomatous dermatofibrosarcoma protuberans (FS-DFSP). The patient subsequently received multiagent chemotherapy in an attempt at limb preservation; however, the tumor continued to progress aggressively, necessitating a midforearm amputation. Review of the amputation specimen prompted further expert consultation, during which pan-TRK immunohistochemistry demonstrated diffuse cytoplasmic staining. Subsequent next-generation sequencing confirmed a TPM3::NTRK1 fusion, establishing the correct diagnosis. This case illustrates a major diagnostic pitfall in the evaluation of high-grade CD34-positive spindle cell sarcomas and underscores the importance of incorporating pan-TRK immunohistochemistry early in the diagnostic work-up. Recognition of this entity is critical, as it directly identifies patients eligible for highly effective TRK-inhibitor therapy.</p>","PeriodicalId":520562,"journal":{"name":"Applied immunohistochemistry & molecular morphology : AIMM","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2026-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148612184","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":"A Robust Protocol for the Establishment, Expansion, Bio-Banking, and Molecular Profiling of Triple-Negative Breast Cancer Organoids.","authors":"Prabhjot Kaur, Shalmoli Bhattacharyya, Parul Gupta, Siddhant Khare, Santhosh Irrinki, Amanjit Bal","doi":"10.1097/PAI.0000000000001344","DOIUrl":"https://doi.org/10.1097/PAI.0000000000001344","url":null,"abstract":"<p><p>Patient-derived organoids (PDOs) offer a powerful in vitro platform to model cancer biology, investigate therapeutic responses, and personalize treatment strategies. Here, we describe a comprehensive and reproducible protocol for establishing 3-dimensional (3D) organoid cultures from surgically resected triple-negative breast cancer (TNBC) samples. Fresh TNBC surgical tissues were processed using a standardized enzymatic and mechanical dissociation protocol followed by 3D culture in Matrigel. Organoids were expanded, cryopreserved, and characterized through histology, immunohistochemistry (IHC), and whole-exome sequencing (WES). Immunophenotypic and genomic concordance was assessed between PDOs and their paired tumors. Organoids were successfully established from resected TNBC tissues, displaying histologic, immunohistochemical, and genomic fidelity supporting high-throughput and personalized research applications.</p>","PeriodicalId":520562,"journal":{"name":"Applied immunohistochemistry & molecular morphology : AIMM","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2026-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148581963","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":"HER2 Immunohistochemical Expression and Fluorescent In Situ Hybridization (FISH) Testing in Clear Cell Carcinoma of the Gynecologic Tract.","authors":"Khaled S Mohamed, Preetha Ramalingam, Barrett C Lawson, Elizabeth D Euscher, Charlotte C Sun, Anais Malpica","doi":"10.1097/PAI.0000000000001340","DOIUrl":"https://doi.org/10.1097/PAI.0000000000001340","url":null,"abstract":"<p><p>The DESTINY-PanTumor02 phase II trial, showing a remarkable response to fam-trastuzumab deruxtecan-nxki (Enhertu), has triggered an increase in HER2 testing for drug eligibility. We evaluated HER2 immunohistochemical (IHC) and FISH testing results and the extent of Enhertu use in gynecologic tract clear cell carcinomas (GT-CCC) at a tertiary care center. Sixty-five GT-CCC with HER2 IHC testing performed at our institution (2018 to 2024) were identified: 49 ovarian (OCCC), 14 endometrial (ECCC), and 2 peritoneal. The 2018 ASCO/CAP criteria were used for HER2 scoring (the standard during the time frame of this study). Overall HER2 IHC scores were: 0 [n=12 (18.5%)], 1+ [n=9 (13.8%)], 2+ [n=40 (61.5%)], 3+ [n=4 (6.2%)]. FISH confirmed amplification in 22.9% OCCCs and 25% ECCCs (18.8% of IHC 2+ and all IHC 3+). Cases with unusual staining patterns (USP; strong nuclear and cytoplasmic) did not show FISH amplification. HER2 0/1+ and cases with USP were more frequent in biopsies (41.7%) and metastatic tumors (45.5%) compared with resections (30.2%) and primary sites (29.6%). Intratumoral heterogeneity was seen in 7.7% of cases. Among HER2 3+ cases, only 1 patient received anti-HER2 therapy (Herceptin followed by Enhertu) and had a mixed response. Of the HER2 2+ with positive FISH, 4 received anti-HER2 therapy, and only 1 patient had a good response. Based on current HER2 eligibility guidelines, our study shows that more than half of GT-CCC cases, that is, IHC HER2+, would be eligible for anti-HER2 therapy. However, few patients in our cohort received this therapy. Further studies are needed to evaluate the efficacy of anti-HER2 therapy for advanced/recurrent GT-CCC.</p>","PeriodicalId":520562,"journal":{"name":"Applied immunohistochemistry & molecular morphology : AIMM","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2026-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148521708","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":"Prognostic Role of TP53 and ARID1A Mutations in Alcohol-Consuming Patients With Uterine Endometrioid Carcinoma.","authors":"Yasemin Adalı","doi":"10.1097/PAI.0000000000001343","DOIUrl":"10.1097/PAI.0000000000001343","url":null,"abstract":"<p><p>Uterine endometrioid carcinoma (UEC) is the most common subtype of endometrial cancer. This study aimed to investigate the prognostic relevance of TP53 and ARID1A mutations in alcohol-consuming UEC patients using publicly available TCGA data. A total of 207 UEC patients were identified from the TCGA CPTAC-3 project. Alcohol consumption status was extracted from self-reported clinical data. Patients were grouped into alcohol consumers and nonconsumers. Kaplan-Meier survival estimates and multivariable Cox proportional hazards models were used to evaluate the association between gene mutation status and overall survival, adjusted for age, stage, and grade. Sensitivity analyses excluded deaths within the first year. Out of 207 patients, 47 (22.7%) reported alcohol consumption. TP53 mutations were more prevalent in alcohol consumers compared with nonconsumers (36.2% vs. 21.3%, P=0.037). In the alcohol-consuming subgroup, patients with wild-type TP53 had significantly worse survival than those with TP53 mutations in sensitivity analysis (HR=2.85; 95% CI: 1.01-8.05; P=0.047). ARID1A wild-type status was associated with increased mortality risk compared with mutated ARID1A in adjusted models (HR=4.00; 95% CI: 1.45-11.01; P=0.007). No statistically significant survival differences were found for PTEN, PIK3CA, or KRAS mutations. TP53 and ARID1A mutation status may have prognostic relevance among alcohol-consuming patients with UEC. These findings suggest a possible gene-environment interaction in endometrial cancer and support the need for further validation through prospective studies.</p>","PeriodicalId":520562,"journal":{"name":"Applied immunohistochemistry & molecular morphology : AIMM","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2026-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148431780","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":"Clinicopathological Features and Expression of CD30, OCT2, and Cyclin D1 in Rosai-Dorfman Disease: A Retrospective Case Series.","authors":"Ying Zhang, Shanshan Li, Yuanchu Liang, Youli Liu, Wenbin Dai","doi":"10.1097/PAI.0000000000001339","DOIUrl":"https://doi.org/10.1097/PAI.0000000000001339","url":null,"abstract":"<p><p>Rosai-Dorfman disease (RDD) is a rare sinus histiocytosis characterized by massive lymphadenopathy. The purpose of this study was to retrospectively analyze the clinicopathological features of RDD and the immunohistochemical expression of CD30, OCT2, and cyclin D1. We also compared RDD with reactive sinus histiocytosis (RSH), Langerhans cell histiocytosis (LCH), inflammatory myofibroblastic tumor (IMT), and IgG4-related disease (IgG4-RD) to assess differences in their immunohistochemical profiles. Ten cases of RDD were included; all patients were male, with a median age of 37 years (range: 17 to 58 y). Three cases involved lymph nodes, while 7 were extranodal. The clinical manifestations were nonspecific and varied with the site involved. Pathologically, most RDD cases showed alternating light and dark histiocytic areas with varying degrees of inflammatory cell infiltration and the characteristic finding of emperipolesis. Immunohistochemistry showed positive rates for CD30, OCT2, and cyclin D1 in RDD of 100%, 90%, and 100%, respectively, which were significantly higher than those in RSH, LCH, IMT, and IgG4-RD. RDD has no specific clinical manifestations, and diagnosis relies primarily on histopathology and immunohistochemistry. CD30, OCT2, and cyclin D1 can serve as ancillary markers for the pathologic diagnosis and differential diagnosis of RDD.</p>","PeriodicalId":520562,"journal":{"name":"Applied immunohistochemistry & molecular morphology : AIMM","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2026-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148431848","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":"Prognostic Impact of CD57⁺ Natural Killer Cells and CD138⁺ Plasma Cells as Minor Components of the Tumor Microenvironment in Mixed Cellularity Classical Hodgkin Lymphoma.","authors":"Sally Salah Abdel-Hakeem, Eman Ahmed Abda, Sanaa Mohamed Sotohy, Raghda Wageh Ahmed Mahfouz","doi":"10.1097/PAI.0000000000001312","DOIUrl":"10.1097/PAI.0000000000001312","url":null,"abstract":"<p><strong>Abstract: </strong>The tumor microenvironment (TME) plays a crucial role in tumor progression and treatment response of classical Hodgkin lymphoma (CHL). Although the contribution of major immune cells like T lymphocytes and macrophages has been widely studied, the prognostic impact of minor populations such as natural killer (NK) cells and plasma cells remains unclear. This study investigates the prognostic significance of plasma cells and NK cells in the TME of CHL, using CD138 and CD57 immunostaining, respectively. A retrospective analysis was conducted on 50 cases of CHL of the mixed cellularity subtype. Specimens were obtained as formalin-fixed, paraffin-embedded (FFPE) blocks from the Pathology Department of the South Egypt Cancer Institute, Assiut University. Immunohistochemical staining for CD57 and CD138 was performed to evaluate NK cells and plasma cells within the TME. A tumor immune profiling was proposed to assess its prognostic significance, based on digital quantification of immune cell infiltration. High CD57+ NK cell infiltration was significantly associated with favorable clinical features, including early-stage disease, absence of B symptoms, good treatment response, and improved overall survival. In contrast, high CD138+ plasma cell expression was associated with advanced-stage disease. These findings suggest that CD57+ NK cells and CD138+ plasma cells may contribute to the prognostic landscape of CHL. Understanding the functional roles of these cells within the TME may enable more personalized and immune-informed strategies for CHL patients.</p>","PeriodicalId":520562,"journal":{"name":"Applied immunohistochemistry & molecular morphology : AIMM","volume":" ","pages":"281-288"},"PeriodicalIF":1.2,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146183954","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":"Role of Twist and Vimentin as Epithelial-Mesenchymal Transition Biomarkers in Oral Squamous Cell Carcinoma: Relation to Cancer-Associated Fibroblasts.","authors":"Eman Kh Allam, Hamdy A-M Metwaly, Eman M E-D Megahed, Marwa M Shakweer, Heba E M Youssef","doi":"10.1097/PAI.0000000000001326","DOIUrl":"10.1097/PAI.0000000000001326","url":null,"abstract":"<p><p>Various molecular pathways regulate oral squamous cell carcinoma (OSCC) progression, including epithelial-mesenchymal transition (EMT), which involves loss of epithelial adhesion, acquisition of mesenchymal traits, and upregulation of markers like Twist and Vimentin. Cancer-associated fibroblasts (CAFs) promote EMT through crosstalk with cancer cells. This study aimed to evaluate Twist and Vimentin IHC expression in OSCC and their correlation with tumor grade and lymph node (LN) metastasis. In addition, Twist and Vimentin mRNA levels were investigated in OSCC cells with and without fibroblasts. The study included 30 OSCC specimens (7 well-differentiated, 14 moderately differentiated, 9 poorly differentiated), with 12 showing LN metastasis. IHC staining for Twist and Vimentin was performed and analyzed. Gene expression was assessed by qRT-PCR in SCC-25, WI-38, and coculture. A Transwell migration assay was also conducted. Twist and Vimentin IRS showed significant correlation with OSCC grades ( P <0.05). Twist IRS had a strong correlation with LN involvement ( P <0.001), and Vimentin was significantly linked to LN metastasis ( P ≤0.001). Twist and Vimentin IRS were highly correlated ( P <0.001). Coculture for 7 days increased Twist and Vimentin expression compared with individual cell cultures. In the migration assay, the SCC + fibroblast group had significantly higher migration (4667.50±1042.24) than SCC alone (1136.67±137.79), P <0.001. Twist and Vimentin expressions as an assessment of EMT might offer better prognostic factors in OSCC and could be helpful detectors of subtle LN metastasis in OSCC.</p>","PeriodicalId":520562,"journal":{"name":"Applied immunohistochemistry & molecular morphology : AIMM","volume":" ","pages":"238-247"},"PeriodicalIF":1.2,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148020440","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":"Exploring the Immune Microenvironment for Predicting Immunotherapy Efficacy in Epstein-Barr Virus-Associated Gastric Cancer.","authors":"Yunjoo Cho, Sung Hee Lim, Seung Tae Kim, Jeeyun Lee, Kyoung-Mee Kim, Soomin Ahn","doi":"10.1097/PAI.0000000000001321","DOIUrl":"10.1097/PAI.0000000000001321","url":null,"abstract":"<p><p>Epstein-Barr virus-associated gastric cancer (EBVaGC) represents an immunogenic subtype of gastric cancer. However, the effectiveness of anti-PD1 agents in EBVaGC remains uncertain, and reliable predictive biomarkers are currently unavailable. Patients with metastatic EBVaGC (n=12) who received anti-PD1 therapy were included. Histologic subtypes were assessed on hematoxylin and eosin-stained slides; PD-L1 expression was evaluated using conventional immunohistochemistry; the immune microenvironment was further characterized by multiplex immunohistochemistry; and all findings were correlated with response to anti-PD1 therapy. Treatment response varied significantly according to the histologic immune classification of EBVaGCs ( P =0.027). A response to treatment was observed in 71.4% (5/7) of carcinomas with Crohn disease-like reactions, whereas no response was observed in conventional adenocarcinomas (0/5). No significant difference was found in the PD-L1 combined positive score between responders and nonresponders, despite a trend toward higher scores in responders ( P =0.081). Quantitative expression measurements using multiplex immunohistochemistry revealed different tumor microenvironments between responders and nonresponders. Higher numbers of PD-L1 + cells ( P =0.048), CD8 + /PD-L1 + cells ( P =0.029), CD4 + cells ( P =0.048), and CD4 + /FOXP3 + cells ( P =0.005) were observed in responders compared with nonresponders. In the tumor area, a higher number of CK + /PD-L1 + cells was observed in responders ( P =0.038). The immune microenvironment was found to influence the response to immunotherapy in EBVaGC. Detailed characterization of the immune microenvironment may enhance the selection of patients with EBVaGCs likely to respond to immunotherapy.</p>","PeriodicalId":520562,"journal":{"name":"Applied immunohistochemistry & molecular morphology : AIMM","volume":" ","pages":"229-237"},"PeriodicalIF":1.2,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147877117","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":"Solving the Puzzle of Hans' Algorithm (HA) Methodological Shortcomings: Canadian Harmonization of Hans' Algorithm for Diffuse Large B-Cell Lymphoma (DLBCL) and Development of Fit-for-Purpose Modified Hans' Algorithm (mHA).","authors":"Emina Torlakovic, Ariz Akhter, Allam Shawwa, Antonio Maietta, Brian Olsen, Catherine A Ross, Carol Cheung, H Rommel R Seno, Jean Deschênes, Pedro Farinha, Philip Berardi, Monalisa Sur, Muhamad Sadek Almiski, Rasha A ElGamal, Adnan Mansoor","doi":"10.1097/PAI.0000000000001324","DOIUrl":"10.1097/PAI.0000000000001324","url":null,"abstract":"<p><p>Hans' algorithm (HA) is the most frequently used surrogate biomarker scheme for subtyping Diffuse large B-cell lymphoma (DLBCL) by the cell-of-origin (COO) into GCB and non-GCB subtypes. The originally published positive and negative predictive value (PPV and NPV) against gene expression profiling (GEP) subtypes were less than perfect and were not fully reproducible in published literature. Furthermore, little is known about how the HA performs in clinical practice. The Canadian Association of Pathologists National Standard Committee for High Complexity Testing (CAP-ACP NSCHCT) initiated a Canada-wide project to assess the current diagnostic accuracy of the HA in clinical practice, harmonize the analytical phase of the IHC assays used for HA, and to optimize its overall diagnostic sensitivity and specificity against GEP subtypes. We divided a DLBCL cohort (n=96), where COO was defined by GEP (Lymph2CX, NanoString technologies) into training (TC, N=45) and validation cohort (VC, N=51) and tissue microarray (TMA)-TC and TMA-VC were constructed. Selected major Canadian laboratories applied their routine CD10, Bcl-6, and MUM1 IHC protocols and sent stained slides to the reference laboratory for review. The IHC protocols from laboratories were designated as \"weak\" (1/10), \"moderate\" (4/10), and \"strong\" (5/10) based on their overall analytical sensitivity. The results of the central review HA readouts were compared with GEP results. Furthermore, in TC, the original HA readout was modified to adjust the cutoff to overall IHC protocol sensitivity. The new readout criteria were also assessed in the VC set. The original HA readout showed good results against GEP for low sensitivity protocol only. For all other laboratories that had IHC protocols with moderate and high analytical sensitivity, a readout was adjusted to higher IHC protocol analytical sensitivity using a cutoff of >30% of >2+ staining intensity. This modification yielded significantly improved diagnostic accuracy against GEP even without any changes to the IHC protocols and was widely applicable to the range of analytical sensitivities of IHC protocols, which are currently in use. IHC biomarkers for HA can be highly accurate and harmonized across different laboratories for clinical application if the following criteria are met: (i) testing laboratories use standardized reference materials to set up and monitor analytical sensitivity, and (ii) the pathologist's readout and cutoff are adjusted to the overall IHC protocol analytical sensitivity.</p>","PeriodicalId":520562,"journal":{"name":"Applied immunohistochemistry & molecular morphology : AIMM","volume":" ","pages":"219-228"},"PeriodicalIF":1.2,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13317902/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147731209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}