Single Center Characterization of a Cohort of Salivary Gland Carcinomas.

Salivary gland cancer (SGC) is a rare cancer that can present a diagnostic challenge to pathologists, with emerging, but still limited options for the treatment of recurrent/metastatic disease. We aimed to characterize the cohort of salivary gland cancers in our institute and generate a tissue microarray (TMA) with clinical data available for immunohistochemical analysis. We extracted the cases of salivary gland cancers in our institute and generated a TMA with 72 patients between 2002 and 2017 with sufficient paraffin block material. Follow-up data were present for all cases. The TMA was stained with three p53 antibodies as well as MSH2, MSH6, PMS2 and MLH1 antibodies. Additionally, we applied fragment analysis based on the Bethesda panel, and the IdyllaTM MSI test to cases with expression loss of any of the mismatch repair proteins (MMR-P) according to our immunohistochemistry (IHC). The investigated cohort shows that pT and pN stage are the only factors independently associated with survival, according to our multivariate analysis (p = 0.037 and p = 0.014). In univariate analysis, risk factors identified in our cohort were also age (p = 0.015), (lympho-) vascular invasion (p = 0.002 and p = 0.003) and risk stratification (p = 0.037). The p53 protein investigated by three antibodies showed no statistically significant association with survival or other tumor characteristics in the investigated cohort. According to MMR-P IHC, six cases of SGC showed an aberrant IHC phenotype. Additional IdyllaTM MSI test and fragment length analysis failed to confirm microsatellite instability. The pT and pN stage are the most important factors for survival in our cohort. In our cohort, antibodies directed against the protein p53 did not contribute to clinical decision-making and were not correlated with any known clinical characteristics. MSI appears to be insignificant in SGCs. Larger cohorts are needed for verification.

Biomechanical Assessment of Liver Integrity: Prospective Evaluation of Mechanical Versus Acoustic MR Elastography.

BACKGROUND: Magnetic resonance elastography (MRE) can quantify tissue biomechanics noninvasively, including pathological hepatic states like metabolic dysfunction-associated steatohepatitis. PURPOSE: To compare the performance of 2D/3D-MRE using the gravitational (GT) transducer concept with the current commercial acoustic (AC) solution utilizing a 2D-MRE approach. Additionally, quality index markers (QIs) were proposed to identify image pixels with sufficient quality for reliably estimating tissue biomechanics. STUDY TYPE: Prospective. POPULATION: One hundred seventy participants with suspected or confirmed liver disease (median age, 57 years [interquartile range (IQR), 46-65]; 66 females), and 11 healthy volunteers (median age, 31 years [IQR, 27-34]; 5 females). FIELD STRENGTH/SEQUENCE: Participants were scanned twice at 1.5 T and 60 Hz vibration frequency: first, using AC-MRE (2D-MRE, spin-echo EPI sequence, 11 seconds breath-hold), and second, using GT-MRE (2D- and 3D-MRE, gradient-echo sequence, 14 seconds breath-hold). ASSESSMENT: Image analysis was performed by four independent radiologists and one biomedical engineer. Additionally, superimposed analytic plane shear waves of known wavelength and attenuation at fixed shear modulus were used to propose pertinent QIs. STATISTICAL TESTS: Spearman's correlation coefficient (r) was applied to assess the correlation between modalities. Interreader reproducibility was evaluated using Bland-Altman bias and reproducibility coefficients. P-values <0.05 were considered statistically significant. RESULTS: Liver stiffness quantified via GT-2D/3D correlated well with AC-2D (r ≥ 0.89 [95% CI: 0.85-0.92]) and histopathological grading (r ≥ 0.84 [95% CI: 0.72-0.91]), demonstrating excellent agreement in Bland-Altman plots and between readers (κ ≥ 0.86 [95% CI: 0.81-0.91]). However, GT-2D showed a bias in overestimating stiffness compared to GT-3D. Proposed QIs enabled the identification of pixels deviating beyond 10% from true stiffness based on a combination of total wave amplitude, temporal sinusoidal nonlinearity, and wave signal-to-noise ratio for GT-3D. CONCLUSION: GT-MRE represents an alternative to AC-MRE for noninvasive liver tissue characterization. Both GT-2D and 3D approaches correlated strongly with the established commercial approach, offering advanced capabilities in abdominal imaging compared to AC-MRE. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 2.

Histopathologic, Molecular, and Clinical Profiling of Lymphoepithelioma-like Carcinoma of the Bladder.

Lymphoepithelioma-like carcinoma of the bladder (LELC-B) is a rare histologic subtype characterized by strong immune cell (IC) infiltrates. A better prognosis and favorable response rates to immune checkpoint inhibitors have been described. We aimed to characterize the molecular profiles and IC infiltration of LELC-B for a better understanding of its therapeutic implications. We identified 11 muscle-invasive bladder cancer cases with pure and mixed LELC-B. Programmed cell death ligand-1 (PD-L1) expression and mismatch repair proteins were evaluated using immunohistochemistry. We calculated the tumor mutational burden and characterized mutational profiles using whole-exome DNA sequencing data. Transcriptomic signatures were detected using the NanoString nCounter PanCancer IO360 Panel. Multiplex immunofluorescence of tumor microenvironment (PD-L1, PanCK, α-SMA, vimentin, CD45, and Ki67) and T cells (CD4, CD3, PD-1, CD163, CD8, and FoxP3) was used to quantify cell populations. All LELC-B cases were highly positive for PD-L1 (median tumor proportion score/tumor cell, 70%; range, 20%-100%; median combined positive score, 100; range, 50-100) and mismatch repair proficient and negative for Epstein-Barr virus infection. IC infiltrates were characterized by a high CD8+ T-cell count and high PD-1/PD-L1 expression on immune and tumor cells. LELC-B showed upregulation of signaling pathways involved in IC response. Most common mutations were found in chromatin remodeling genes causing epigenetic dysregulation. All LELC-B cases showed high tumor mutational burden with a median of 39 mutations/Mb (IQR, 29-66 mutations/Mb). In conclusion, LELC-B is a highly immunogenic tumor, showing strong upregulation of PD-1/PD-L1 and making immune checkpoint inhibitors a promising treatment option.

Epigenetic profiling of prostate cancer reveals potential prognostic signatures.

PURPOSE: While epigenetic profiling discovered biomarkers in several tumor entities, its application in prostate cancer is still limited. We explored DNA methylation-based deconvolution of benign and malignant prostate tissue for biomarker discovery and the potential of radiomics as a non-invasive surrogate. METHODS: We retrospectively included 30 patients (63 [58-79] years) with prostate cancer (PCa) who had a multiparametric MRI of the prostate before radical prostatectomy between 2014 and 2019. The control group comprised four patients with benign prostate tissue adjacent to the PCa lesions and four patients with benign prostatic hyperplasia. Tissue punches of all lesions were obtained. DNA methylation analysis and reference-free in silico deconvolution were conducted to retrieve Latent Methylation Components (LCMs). LCM-based clustering was analyzed for cellular composition and correlated with clinical disease parameters. Additionally, PCa and adjacent benign lesions were analyzed using radiomics to predict the epigenetic signatures non-invasively. RESULTS: LCMs identified two clusters with potential prognostic impact. Cluster one was associated with malignant prostate tissue (p < 0.001) and reduced immune-cell-related signatures (p = 0.004) of CD19 and CD4 cells. Cluster one comprised exclusively malignant prostate tissue enriched for significant prostate cancer and advanced tumor stages (p < 0.03 for both). No radiomics model could non-invasively predict the epigenetic clusters. CONCLUSION: Epigenetic clusters were associated with prognostically and clinically relevant metrics in prostate cancer. Further, immune cell-related signatures differed significantly between prognostically favorable and unfavorable clusters. Further research is necessary to explore potential diagnostic and therapeutic implications.

Small duct and large duct type intrahepatic cholangiocarcinoma reveal distinct patterns of immune signatures.

PURPOSE: Dedicated gene signatures in small (SD-iCCA) and large (LD-iCCA) duct type intrahepatic cholangiocarcinoma remain unknown. We performed immune profiling in SD- and LD-iCCA to identify novel biomarker candidates for personalized medicine. METHODS: Retrospectively, 19 iCCA patients with either SD-iCCA (n = 10, median age, 63.1 years (45-86); men, 4) or LD-iCCA (n = 9, median age, 69.7 years (62-85); men, 5)) were included. All patients were diagnosed and histologically confirmed between 04/2009 and 01/2021. Tumor tissue samples were processed for differential expression profiling using NanoString nCounter® PanCancer Immune Profiling Panel. RESULTS: With the exception of complement signatures, immune-related pathways were broadly downregulated in SD-iCCA vs. LD-iCCA. A total of 20 immune-related genes were strongly downregulated in SD-iCCA with DMBT1 (log2fc = -5.39, p = 0.01) and CEACAM6 (log2fc = -6.38, p = 0.01) showing the strongest downregulation. Among 7 strongly (log2fc > 2, p ≤ 0.02) upregulated genes, CRP (log2fc = 5.06, p = 0.02) ranked first, and four others were associated with complement (C5, C4BPA, C8A, C8B). Total tumor-infiltrating lymphocytes (TIL) signature was decreased in SD-iCCA with elevated ratios of exhausted-CD8/TILs, NK/TILs, and cytotoxic cells/TILs while having decreased ratios of B-cells/TILs, mast cells/TILs and dendritic cells/TILs. The immune profiling signatures in SD-iCCA revealed downregulation in chemokine signaling pathways inclulding JAK2/3 and ERK1/2 as well as nearly all cytokine-cytokine receptor interaction pathways with the exception of the CXCL1/CXCR1-axis. CONCLUSION: Immune patterns differed in SD-iCCA versus LD-iCCA. We identified potential biomarker candidate genes, including CRP, CEACAM6, DMBT1, and various complement factors that could be explored for augmented diagnostics and treatment decision-making.

Impact of homologous recombination repair/BReast CAncer (BRCA) gene alterations on survival in a real-world setting of metastatic prostate cancer.

OBJECTIVE: To investigate alterations of homologous recombination repair (HRR) and especially BReast CAncer 1/2 (BRCA1/2) gene on overall survival (OS). Moreover, to explore the effect of inhibition of poly(ADP-ribose)-polymerase (PARPi) as systemic therapy for metastatic castration-resistant prostate cancer (mCRPC). PATIENTS AND METHODS: Of all HRR-screened patients with metastatic prostate cancer, baseline characteristics were sampled. Kaplan-Meier estimates and multivariable Cox regression models predicted the effect of HRR/BRCA1/2 alterations on OS. RESULTS: Of 196 eligible patients, 61 (31%) harboured any HRR and 40 (20%) BRCA1/2 alterations. Of HRR alterations, 40 (66%) vs six (10%) vs five (8.2%) vs four (6.6%) vs two (3.3%) vs four (6.6%) were BRCA1/2 vs Ataxia-telangiectasia mutated kinase (ATM) vs checkpoint kinase 2 (CHEK2) vs cyclin-dependent kinase 12 (CDK12) vs Fanconi anaemia complementation Group A (FANCA) vs positive for other mutations. Of these, 30% received a PARPi. OS differed significantly between HRR-positive vs -negative patients. Specifically in hormone-sensitive prostate cancer, the median OS was 63 (HRR positive) vs 57 (BRCA1/2 positive) vs 113 months (HRR negative) (P ≤ 0.01). In mCRPC, OS was 42 (HRR positive) vs 41 (BRCA1/2 positive) vs 70 months (HRR negative) (P ≤ 0.01). HRR and BRCA1/2 alterations were associated with worse OS after multivariable adjustment. Finally, patients with mCRPC with BRCA1/2 mutation treated without PARPi harboured worse OS than patients with BRCA1/2 mutation and PARPi therapy (median OS: 33 vs 48 months, P < 0.03). CONCLUSION: Incidence of HRR alteration in a clinical real-world setting is high when using blood- and tissue-based tests. Patients with HRR/BRCA alterations have worse outcomes resulting in significant OS differences between HRR/BRCA-positive patients with mCRPC with and without PARPi usage vs HRR/BRCA-negative patients.

Fluorescence Confocal Microscopy Can Accelerate Diagnosis of Cervical Lymphadenopathy.

Fluorescence confocal microscopy (FCM) is an optical technique that uses laser light sources of different wavelengths to generate real-time images of fresh, unfixed tissue specimens. Unlike conventional histologic evaluation methods, FCM is able to assess fresh tissue samples without the associated cryo artifacts typically observed after frozen sectioning. The purpose of this study was to evaluate the utility of FCM imaging in the differential diagnosis of cervical lymphadenopathy. Twenty-two cervical lymph node specimens from patients with lymphadenopathy of unknown origin were imaged by FCM. Two pathologists independently evaluated the scans for suspicion of malignancy and preliminary diagnosis. Malignancy was reliably excluded or confirmed by both pathologists with a sensitivity of 90.9% for pathologist 1 and 100% for pathologist 2. The specificity was 100% for both pathologists. For the preliminary diagnosis, almost perfect agreement with the final diagnosis was observed for both pathologists (κ = 0.94 for pathologist 1 and κ = 1.00 for pathologist 2). This is the first study to investigate lymph node specimens with different diagnoses, including lymphoma, using FCM. Our results indicate that differential diagnosis of lymph node specimens is feasible in FCM images, thus encouraging further exploration of FCM imaging in lymph node specimens to accelerate diagnosis and open the possibility of digitizing diagnosis on fresh, unfixed tissue.

Erk Inhibition as a Promising Therapeutic Strategy for High IL-8-Secreting and Low SPTAN1-Expressing Colorectal Cancer.

Tumor recurrence and drug resistance are responsible for poor prognosis in colorectal cancer (CRC). DNA mismatch repair (MMR) deficiency or elevated interleukin-8 (IL-8) levels are characteristics of CRCs, which have been independently correlated with treatment resistance to common therapies. We recently demonstrated significantly impaired therapeutical response and increased IL-8 release of CRC cell lines with reduced expression of MMR protein MLH1 as well as cytoskeletal non-erythrocytic spectrin alpha II (SPTAN1). In the present study, decreased intratumoral MLH1 and SPTAN1 expression in CRCs could be significantly correlated with enhanced serum IL-8. Furthermore, using stably reduced SPTAN1-expressing SW480, SW620 or HT-29 cell lines, the RAS-mediated RAF/MEK/ERK pathway was analyzed. Here, a close connection between low SPTAN1 expression, increased IL-8 secretion, enhanced extracellular-signal-regulated kinase (ERK) phosphorylation and a mesenchymal phenotype were detected. The inhibition of ERK by U0126 led to a significant reduction in IL-8 secretion, and the combination therapy of U0126 with FOLFOX optimizes the response of corresponding cancer cell lines. Therefore, we hypothesize that the combination therapy of FOLFOX and U0126 may have great potential to improve drug efficacy on this subgroup of CRCs, showing decreased MLH1 and SPTAN1 accompanied with high serum IL-8 in affected patients.

[Rare tumors and tumor types of the urinary system in the 5th edition of the WHO classification 2022]. / Seltenere Tumoren und Tumortypen des ableitenden Harnsystems in der 5. Aufl. der WHO-Klassifikation 2022.

The 5th edition of the World Health Organization (WHO) classification of tumors of the urinary tract and male genital organs introduced both general and specific changes in structure, classification, and nomenclature. This also applies to rarer tumors and tumor subtypes of the urinary system. Knowledge of these changes is relevant for routine histopathological work. This article provides an overview of the main new features of the rarer tumors and tumor subtypes of the urinary system in the new edition of the WHO classification.

Development, testing and validation of a targeted NGS-panel for the detection of actionable mutations in lung cancer (NSCLC) using anchored multiplex PCR technology in a multicentric setting.

Lung cancer is a paradigm for a genetically driven tumor. A variety of drugs were developed targeting specific biomarkers requiring testing for tumor genetic alterations in relevant biomarkers. Different next-generation sequencing technologies are available for library generation: 1) anchored multiplex-, 2) amplicon based- and 3) hybrid capture-based-PCR. Anchored multiplex PCR-based sequencing was investigated for routine molecular testing within the national Network Genomic Medicine Lung Cancer (nNGM). Four centers applied the anchored multiplex ArcherDX-Variantplex nNGMv2 panel to re-analyze samples pre-tested during routine diagnostics. Data analyses were performed by each center and compiled centrally according to study design. Pre-defined standards were utilized, and panel sensitivity was determined by dilution experiments. nNGMv2 panel sequencing was successful in 98.9% of the samples (N = 90). With default filter settings, all but two potential MET exon 14 skipping variants were identified at similar allele frequencies. Both MET variants were found with an adapted calling filter. Three additional variants (KEAP1, STK11, TP53) were called that were not identified in pre-testing analyses. Only total DNA amount but not a qPCR-based DNA quality score correlated with average coverage. Analysis was successful with a DNA input as low as 6.25 ng. Anchored multiplex PCR-based sequencing (nNGMv2) and a sophisticated user-friendly Archer-Analysis pipeline is a robust and specific technology to detect tumor genetic mutations for precision medicine of lung cancer patients.

[Fluorescence confocal microscopy-complete digitization of pathology]. / Fluoreszenzbasierte Konfokalmikroskopie ­ vollständige Digitalisierung der Pathologie.

BACKGROUND: Fluorescence-based confocal microscopy (FCM) can be used to create virtual H&E sections in real time. So far, FCM has been used in dermato-, uro-, and gynecopathology. FCM allows the creation of a completely digitized frozen section, which could potentially replace conventional frozen sections in the future. OBJECTIVE: The aim of the current work is to implement FCM technology as a component of fully digitized processes in the pathological workflow. For this purpose, the current use of FCM in liver transplant pathology will be extended to other disciplines such as urology and otorhinolaryngology. MATERIALS AND METHODS: The FCM technique continues to be used prospectively on native tissue samples from potential donor livers. Conventional frozen sections are used comparatively to virtual FCM scans. RESULTS: The data show a nearly perfect agreement for the detection of cholangitis, fibrosis, and malignancy, and a high level of agreement for, e.g., macrovesicular steatosis, inflammation, steatohepatitis, and necrosis between virtual FCM scans and conventional routine diagnostic frozen sections. CONCLUSION: Since the availability of time- and cost-intensive frozen section diagnostics in the context of transplant pathology in continuous operation (24/7) is now only established at very few university centers in Germany due to an increasing shortage of specialists, the use of FCM could be an important building block in the current process leading towards a fully digitized pathology workflow and should thus be extended to various disciplines.

Feasibility of Next-generation Sequencing of Liquid Biopsy (Circulating Tumor DNA) Samples and Tumor Tissue from Patients with Metastatic Prostate Cancer in a Real-world Clinical Setting in Germany.

BACKGROUND AND OBJECTIVE: With European Medicines Agency approval of PARP inhibitors in metastatic castration-resistant prostate cancer and ongoing trials in metastatic hormone-sensitive prostate cancer, detection of genetic alterations in BRCA1/2 and other homologous recombination repair genes has gained an important role. Our aim was to investigate the feasibility and comparability of comprehensive next-generation sequencing (NGS) of liquid biopsy (LB; circulating tumor DNA) and tumor tissue (TT) samples in a real-world clinical setting. METHODS: The study cohort consisted of 50 patients with metastatic prostate cancer (mPC) who had TT NGS performed for BRCA1/2 alterations and consent for additional LB NGS. The Oncomine Comprehensive Assay v3 (Thermo Fisher Scientific, Waltham, MA, USA) was used for TT NGS. The Guardant360 83-gene assay (Guardant Health, Palo Alto, CA, USA) was used for LB NGS, including all types of somatic alterations, microsatellite instability, and blood tumor mutational burden. We calculated BRCA1/2 alteration rates and the negative percentage agreement (NPA) and positive percentage agreement (PPA) between TT and LB results. KEY FINDINGS AND LIMITATIONS: TT NGS was successful in 44/50 patients (88%), with pathogenic BRCA1/2 alterations detected in four (9%). LB NGS was successful in all 50 patients (100%), with BRCA1/2 alterations detected in ten (20%). In a subgroup analysis for the 44 patients with successful TT NGS, NPA was 85% and PPA was 50%. The median time between TT sample collection and blood sampling for NGS was 132 wk (IQR 94-186). The limited sample size and differences in the time of NGS assessment are limitations. CONCLUSIONS AND CLINICAL IMPLICATIONS: LB NGS resulted in a higher detection rate for BRCA1/2 alterations in comparison to conventional TT NGS (20% vs 9%). Ideally, BRCA1/2 testing should be based on both approaches to identify all patients with mPC eligible for PARP inhibitor therapy. PATIENT SUMMARY: Our study shows that genetic tests for both tumor tissue and blood samples results in higher rates of detection of BRCA1/2 gene alterations in patients with metastatic prostate cancer.

High Concordance of Different Assays in the Determination of Homologous Recombination Deficiency-Associated Genomic Instability in Ovarian Cancer.

PURPOSE: Poly(ADP-ribose) polymerase inhibitors (PARPi) have shown promising clinical results in the treatment of ovarian cancer. Analysis of biomarker subgroups consistently revealed higher benefits for patients with homologous recombination deficiency (HRD). The test that is most often used for the detection of HRD in clinical studies is the Myriad myChoice assay. However, other assays can also be used to assess biomarkers, which are indicative of HRD, genomic instability (GI), and BRCA1/2 mutation status. Many of these assays have high potential to be broadly applied in clinical routine diagnostics in a time-effective decentralized manner. Here, we compare the performance of a multitude of alternative assays in comparison with Myriad myChoice in high-grade serous ovarian cancer (HGSOC). METHODS: DNA from HGSOC samples was extracted from formalin-fixed paraffin-embedded tissue blocks of cases previously run with the Myriad myChoice assay, and GI was measured by multiple molecular assays (CytoSNP, AmoyDx, Illumina TSO500 HRD, OncoScan, NOGGO GISv1, QIAseq HRD Panel and whole genome sequencing), applying different bioinformatics algorithms. RESULTS: Application of different assays to assess GI, including Myriad myChoice, revealed high concordance of the generated scores ranging from very substantial to nearly perfect fit, depending on the assay and bioinformatics pipelines applied. Interlaboratory comparison of assays also showed high concordance of GI scores. CONCLUSION: Assays for GI assessment not only show a high concordance with each other but also in correlation with Myriad myChoice. Thus, almost all of the assays included here can be used effectively to assess HRD-associated GI in the clinical setting. This is important as PARPi treatment on the basis of these tests is compliant with European Medicines Agency approvals, which are methodologically not test-bound.

The Role of Hypoxia-Inducible Factor 1 Alpha in Acute-on-Chronic Liver Failure.

Acute-on-chronic liver failure (ACLF) is associated with increased mortality. Specific therapy options are limited. Hypoxia-inducible factor 1 alpha (HIF-1α) has been linked to the pathogenesis of chronic liver disease (CLD), but the role of HIF-1α in ACLF is poorly understood. In the current study, different etiologies of CLD and precipitating events triggering ACLF were used in four rodent models. HIF-1α expression and the intracellular pathway of HIF-1α induction were investigated using real-time quantitative PCR. The results were verified by Western blotting and immunohistochemistry for extrahepatic HIF-1α expression using transcriptome analysis. Exploratory immunohistochemical staining was performed to assess HIF-1α in human liver tissue. Intrahepatic HIF-1α expression was significantly increased in all animals with ACLF, regardless of the underlying etiology of CLD or the precipitating event. The induction of HIF-1α was accompanied by the increased mRNA expression of NFkB1 and STAT3 and resulted in a marked elevation of mRNA levels of its downstream genes. Extrahepatic HIF-1α expression was not elevated. In human liver tissue samples, HIF-1α expression was elevated in CLD and ACLF. Increased intrahepatic HIF-1α expression seems to play an important role in the pathogenesis of ACLF, and future studies are pending to investigate the role of therapeutic HIF inhibitors in ACLF.

[The model transferability of AI in digital pathology : Potential and reality]. / Die Modelltransferierbarkeit von KI in der digitalen Pathologie : Potenzial und Realität.

OBJECTIVE: Artificial intelligence (AI) holds the potential to make significant advancements in pathology. However, its actual implementation and certification for practical use are currently limited, often due to challenges related to model transferability. In this context, we investigate the factors influencing transferability and present methods aimed at enhancing the utilization of AI algorithms in pathology. MATERIALS AND METHODS: Various convolutional neural networks (CNNs) and vision transformers (ViTs) were trained using datasets from two institutions, along with the publicly available TCGA-MIBC dataset. These networks conducted predictions in urothelial tissue and intrahepatic cholangiocarcinoma (iCCA). The objective was to illustrate the impact of stain normalization, the influence of various artifacts during both training and testing, as well as the effects of the NoisyEnsemble method. RESULTS: We were able to demonstrate that stain normalization of slides from different institutions has a significant positive effect on the inter-institutional transferability of CNNs and ViTs (respectively +13% and +10%). In addition, ViTs usually achieve a higher accuracy in the external test (here +1.5%). Similarly, we showcased how artifacts in test data can negatively affect CNN predictions and how incorporating these artifacts during training leads to improvements. Lastly, NoisyEnsembles of CNNs (better than ViTs) were shown to enhance transferability across different tissues and research questions (+7% Bladder, +15% iCCA). DISCUSSION: It is crucial to be aware of the transferability challenge: achieving good performance during development does not necessarily translate to good performance in real-world applications. The inclusion of existing methods to enhance transferability, such as stain normalization and NoisyEnsemble, and their ongoing refinement, is of importance.

[Challenges of automation in quantitative evaluation of liver biopsies : Automatic quantification of liver steatosis]. / Herausforderungen der Automation bei der quantitativen Auswertung von Leberbiopsien : Automatische Quantifizierung von Leberverfettung.

BACKGROUND: Metabolic dysfunction-associated steatotic liver disease (MASLD), or non-alcoholic fatty liver disease (NAFLD), is a common disease that is diagnosed through manual evaluation of liver biopsies, an assessment that is subject to high interobserver variability (IBV). IBV can be reduced using automated methods. OBJECTIVES: Many existing computer-based methods do not accurately reflect what pathologists evaluate in practice. The goal is to demonstrate how these differences impact the prediction of hepatic steatosis. Additionally, IBV complicates algorithm validation. MATERIALS AND METHODS: Forty tissue sections were analyzed to detect steatosis, nuclei, and fibrosis. Data generated from automated image processing were used to predict steatosis grades. To investigate IBV, 18 liver biopsies were evaluated by multiple observers. RESULTS: Area-based approaches yielded more strongly correlated results than nucleus-based methods (⌀ Spearman rho [ρ] = 0.92 vs. 0.79). The inclusion of information regarding tissue composition reduced the average absolute error for both area- and nucleus-based predictions by 0.5% and 2.2%, respectively. Our final area-based algorithm, incorporating tissue structure information, achieved a high accuracy (80%) and strong correlation (⌀ Spearman ρ = 0.94) with manual evaluation. CONCLUSION: The automatic and deterministic evaluation of steatosis can be improved by integrating information about tissue composition and can serve to reduce the influence of IBV.

Heterogeneity of small duct- and large duct-type intrahepatic cholangiocarcinoma.

AIMS: The histological subtype of intrahepatic cholangiocarcinoma (iCCA) is associated with different mutational characteristics that impact clinical management. So far, data are lacking on the presence of small duct iCCA (SD-iCCA) and large duct iCCA (LD-iCCA) in a single patient. The aim of the current study was to determine the presence and degree of intratumoural heterogeneity of SD- and LD-iCCA features in different tumour regions. METHODS AND RESULTS: All patients treated with surgically resected iCCA at Frankfurt University Hospital between December 2005 and March 2023 were retrospectively analysed. Histomorphological features of SD- and LD-iCCA were evaluated by an expert hepatobiliary pathologist. Tissue samples suspicious for subtype heterogeneity were further investigated. Immunohistochemistry for N-cadherin, S100P, MUC5AC, MUC6, TFF1 and AGR2 and mutational profiling with the Illumina TruSight Oncology 500 (TSO500) assay were performed separately for the SD- and LD-iCCA regions. Of 129 patients with surgically resected iCCA, features of either SD- or LD-iCCA were present in 67.4% (n = 87) and 24.8% of the patients (n = 32), respectively; 7.8% (n = 10) had histomorphological features of both SD- and LD-iCCA, seven patients (5.4%) of which had sufficient formalin-fixed, paraffin-embedded tissue for further analysis. Heterogeneity of both subtypes could be confirmed with immunohistochemistry. In five of seven (71.4%) patients, molecular profiling revealed intratumoural differences in genetic alterations between the SD- and LD-iCCA region. In one patient, a BRAF mutation (p.V600E) was found in the SD-iCCA but not in the LD-iCCA region of the tumour. CONCLUSIONS: A marked portion of patients with iCCA exhibits both SD- and LD-iCCA in different tumour regions. In case of the presence of histopathological heterogeneity, mutational profiling should be considered to avoid missing therapeutically relevant genetic alterations.

CT-guided core needle biopsies of head and neck tumors: a comprehensive monocenter analysis of safety and outcomes.

BACKGROUND: Although core needle biopsy is an important tool in minimally invasive tissue sampling and diagnostics for head and neck masses, comprehensive data about safety and outcomes is lacking. PURPOSE: To retrospectively evaluate the diagnostic performance and safety of computed tomography (CT)-guided percutaneous core needle biopsy of head and neck masses. MATERIAL AND METHODS: This retrospective single-center study included patients from 04/2007 to 12/2021, and a total of 156 core needle biopsies were evaluated. The initial histopathological results were compared with the long-term final diagnosis to evaluate the diagnostic yield of CT-guided core needle biopsies. The patients' age, sex, and history of malignancy, as well as procedural complications and radiation exposure were collected. RESULTS: A total of 156 biopsies of 150 patients (mean age 56 years ± 17; 89 men) were evaluated. 57.3% (86/150) of patients had a history of malignancy. 55.1% (86/156) of the lesions were accessed by an infrahyoid needle approach. 92.9% (145/156) of biopsies yielded conclusive results. There were no false positives and 4 false negatives, resulting in a total false negative rate of 2.7% (4/145) and a total diagnostic yield of 90.4% (141/156). There were nine puncture-related complications (9/156-5.7%). None of the complications required further reintervention. The average dose length product was 311.3 mGy × cm. CONCLUSION: CT-guided core needle biopsies of head and neck masses showed excellent results with high diagnostic yield and clinical safety. CLINICAL RELEVANCE STATEMENT: General anesthesia for open biopsy carries a higher risk for elderly patients, and fine needle aspiration has a poor reputation in terms of its diagnostic yield. This study focuses on safety and diagnostic yield of CT-guided core needle biopsies. KEY POINTS: • CT-guided core needle biopsy in head and neck tumors was a reliable and safe procedure. • The most common cause for an inconclusive biopsy result was a shortage of tissue collected during the biopsy. • During our study period of nearly 15 years, the radiation exposure of head and neck biopsies decreased.

[Histomolecular classification of urothelial carcinoma of the urinary bladder : From histological phenotype to genotype and back]. / Histomolekulare Klassifikation des Urothelkarzinoms der Harnblase : Vom histologischen Phänotyp zum Genotyp und zurück.

BACKGROUND: Of all urothelial carcinomas (UCs), 25% are muscle invasive and associated with a 5-year overall survival rate of 50%. Findings regarding the molecular classification of muscle-invasive urothelial carcinomas (MIUCs) have not yet found their way into clinical practice. OBJECTIVES: Prediction of molecular consensus subtypes in MIUCs with artificial intelligence (AI) based on histologic hematoxylin-eosin (HE) sections. METHODS: Pathologic review and annotation of The Cancer Genome Atlas (TCGA) Bladder Cancer (BLCA) Cohort (N = 412) and the Dr. Senckenberg Institute of Pathology (SIP) BLCA Cohort (N = 181). An AI model for the prediction of molecular subtypes based on annotated histomorphology was trained. RESULTS: For a five-fold cross-validation with TCGA cases (N = 274), an internal TCGA test set (N = 18) and an external SIP test set (N = 27), we reached mean area under the receiver operating characteristic curve (AUROC) scores of 0.73, 0.8 and 0.75 for the classification of the used molecular subtypes "luminal", "basal/squamous" and "stroma-rich". By training on correlations to individual molecular subtypes, rather than training on one subtype assignment per case, the AI prediction of subtypes could be significantly improved. DISCUSSION: Follow-up studies with RNA extraction from various areas of AI-predicted molecular heterogeneity may improve molecular classifications and thereby AI algorithms trained on these classifications.