ctDNA whole exome sequencing in pancreatic ductal adenocarcinoma unveils organ-dependent metastatic mechanisms and identifies actionable alterations in fast progressing patients.

Understanding progression mechanisms and developing new targeted therapies is imperative in pancreatic ductal adenocarcinoma (PDAC). In this study, 80 metastatic PDAC patients were prospectively recruited and divided into discovery (n=37) and validation (n=43) cohorts. Tumor and plasma samples taken at diagnosis were pair analyzed using whole exome sequencing (WES) in patients belonging to the discovery cohort alone. The variant allele frequency (VAF) of KRAS mutations was measured by ddPCR in plasma at baseline and response assessment in all patients. Plasma WES identified at least one pathogenic variant across the cohort, uncovering oncogenic mechanisms, DNA repair, microsatellite instability, and alterations in the TGFb pathway. Interestingly, actionable mutations were mostly found in plasma rather than tissue. Patients with shorter survival showed enrichment in cellular organization regulatory pathways. Through WES we could identify a specific molecular profile of patients with liver metastasis, which exhibited exclusive mutations in genes related to the adaptive immune response pathway, highlighting the importance of the immune system in liver metastasis development. Moreover, KRAS mutations in plasma (both at diagnosis and persistent at follow-up) correlated with shorter progression free survival (PFS). Patients presenting a reduction of over 84.75 % in KRAS VAF at response assessment had similar PFS to KRAS-negative patients. Overall, plasma WES reveals molecular profiles indicative of rapid progression, potentially actionable targets, and associations between adaptive immune response pathway alterations and liver tropism.

Hydroxycitrate delays early mortality in mice and promotes muscle regeneration while inducing a rich hepatic energetic status.

ATP citrate lyase (ACLY) inhibitors have the potential of modulating central processes in protein, carbohydrate, and lipid metabolism, which can have relevant physiological consequences in aging and age-related diseases. Here, we show that hepatic phospho-active ACLY correlates with overweight and Model for End-stage Liver Disease score in humans. Wild-type mice treated chronically with the ACLY inhibitor potassium hydroxycitrate exhibited delayed early mortality. In AML12 hepatocyte cultures, the ACLY inhibitors potassium hydroxycitrate, SB-204990, and bempedoic acid fostered lipid accumulation, which was also observed in the liver of healthy-fed mice treated with potassium hydroxycitrate. Analysis of soleus tissue indicated that potassium hydroxycitrate produced the modulation of wound healing processes. In vivo, potassium hydroxycitrate modulated locomotor function toward increased wire hang performance and reduced rotarod performance in healthy-fed mice, and improved locomotion in mice exposed to cardiotoxin-induced muscle atrophy. Our findings implicate ACLY and ACLY inhibitors in different aspects of aging and muscle regeneration.

Development and validation of an image biomarker to identify metabolic dysfunction associated steatohepatitis: MR-MASH score.

BACKGROUND AND AIMS: Diagnosis of metabolic dysfunction-associated steatohepatitis (MASH) requires histology. In this study, a magnetic resonance imaging (MRI) score was developed and validated to identify MASH in patients with metabolic dysfunction-associated steatotic liver disease (MASLD). Secondarily, a screening strategy for MASH diagnosis was investigated. METHODS: This prospective multicentre study included 317 patients with biopsy-proven MASLD and contemporaneous MRI. The discovery cohort (Spain, Portugal) included 194 patients. NAFLD activity score (NAS) and fibrosis were assessed with the NASH-CRN histologic system. MASH was defined by the presence of steatosis, lobular inflammation, and ballooning, with NAS ≥4 with or without fibrosis. An MRI-based composite biomarker of Proton Density Fat Fraction and waist circumference (MR-MASH score) was developed. Findings were afterwards validated in an independent cohort (United States, Spain) with different MRI protocols. RESULTS: In the derivation cohort, 51% (n = 99) had MASH. The MR-MASH score identified MASH with an AUC = .88 (95% CI .83-.93) and strongly correlated with NAS (r = .69). The MRI score lower cut-off corresponded to 88% sensitivity with 86% NPV, while the upper cut-off corresponded to 92% specificity with 87% PPV. MR-MASH was validated with an AUC = .86 (95% CI .77-.92), 91% sensitivity (lower cut-off) and 87% specificity (upper cut-off). A two-step screening strategy with sequential MR-MASH examination performed in patients with indeterminate-high FIB-4 or transient elastography showed an 83-84% PPV to identify MASH. The AUC of MR-MASH was significantly higher than that of the FAST score (p < .001). CONCLUSIONS: The MR-MASH score has clinical utility in the identification and management of patients with MASH at risk of progression.

Pancreatic steatosis and iron overload increases cardiovascular risk in non-alcoholic fatty liver disease.

Objective: To assess the prevalence of pancreatic steatosis and iron overload in non-alcoholic fatty liver disease (NAFLD) and their correlation with liver histology severity and the risk of cardiometabolic diseases. Method: A prospective, multicenter study including NAFLD patients with biopsy and paired Magnetic Resonance Imaging (MRI) was performed. Liver biopsies were evaluated according to NASH Clinical Research Network, hepatic iron storages were scored, and digital pathology quantified the tissue proportionate areas of fat and iron. MRI-biomarkers of fat fraction (PDFF) and iron accumulation (R2*) were obtained from the liver and pancreas. Different metabolic traits were evaluated, cardiovascular disease (CVD) risk was estimated with the atherosclerotic CVD score, and the severity of iron metabolism alteration was determined by grading metabolic hiperferritinemia (MHF). Associations between CVD, histology and MRI were investigated. Results: In total, 324 patients were included. MRI-determined pancreatic iron overload and moderate-to severe steatosis were present in 45% and 25%, respectively. Liver and pancreatic MRI-biomarkers showed a weak correlation (r=0.32 for PDFF, r=0.17 for R2*). Pancreatic PDFF increased with hepatic histologic steatosis grades and NASH diagnosis (p<0.001). Prevalence of pancreatic steatosis and iron overload increased with the number of metabolic traits (p<0.001). Liver R2* significantly correlated with MHF (AUC=0.77 [0.72-0.82]). MRI-determined pancreatic steatosis (OR=3.15 [1.63-6.09]), and iron overload (OR=2.39 [1.32-4.37]) were independently associated with high-risk CVD. Histologic diagnosis of NASH and advanced fibrosis were also associated with high-risk CVD. Conclusion: Pancreatic steatosis and iron overload could be of utility in clinical decision-making and prognostication of NAFLD.

"Proteotranscriptomic analysis of advanced colorectal cancer patient derived organoids for drug sensitivity prediction".

BACKGROUND: Patient-derived organoids (PDOs) from advanced colorectal cancer (CRC) patients could be a key platform to predict drug response and discover new biomarkers. We aimed to integrate PDO drug response with multi-omics characterization beyond genomics. METHODS: We generated 29 PDO lines from 22 advanced CRC patients and provided a morphologic, genomic, and transcriptomic characterization. We performed drug sensitivity assays with a panel of both standard and non-standard agents in five long-term cultures, and integrated drug response with a baseline proteomic and transcriptomic characterization by SWATH-MS and RNA-seq analysis, respectively. RESULTS: PDOs were successfully generated from heavily pre-treated patients, including a paired model of advanced MSI high CRC deriving from pre- and post-chemotherapy liver metastasis. Our PDOs faithfully reproduced genomic and phenotypic features of original tissue. Drug panel testing identified differential response among PDOs, particularly to oxaliplatin and palbociclib. Proteotranscriptomic analyses revealed that oxaliplatin non-responder PDOs present enrichment of the t-RNA aminoacylation process and showed a shift towards oxidative phosphorylation pathway dependence, while an exceptional response to palbociclib was detected in a PDO with activation of MYC and enrichment of chaperonin T-complex protein Ring Complex (TRiC), involved in proteome integrity. Proteotranscriptomic data fusion confirmed these results within a highly integrated network of functional processes involved in differential response to drugs. CONCLUSIONS: Our strategy of integrating PDOs drug sensitivity with SWATH-mass spectrometry and RNA-seq allowed us to identify different baseline proteins and gene expression profiles with the potential to predict treatment response/resistance and to help in the development of effective and personalized cancer therapeutics.

Differential diagnosis of myxoid soft tissue tumors. Experience in the Clinical University Hospital of Valencia.

Soft tissue tumors with myxoid components are often a diagnostic challenge for the pathologist. We retrospectively reviewed 41 cases of soft tissue tumors with myxoid components diagnosed in our center over a five-year period. The most frequent diagnoses were myxofibrosarcoma and myxoid liposarcoma, followed by low-grade fibromyxoid sarcoma, low-grade fibromyxoid tumor and myxoid neurofibroma. Other diagnoses included were extraskeletal myxoid chondrosarcoma, myxoinflammatory fibroblastic sarcoma, low-grade myxoliposarcoma, myofibrosarcoma, fibromatosis, solitary fibrous tumor, non-ossifying variant of ossifying fibromyxoid tumor and ancient neurinoma with myxoid degeneration. Immunohistochemical and molecular biology studies contributed significantly to the diagnosis. We highlight the importance of immunohistochemistry for MUC4 in the diagnosis of low-grade fibromyxoid sarcoma, and underscore the need for molecular studies in selected cases. Furthermore, several myxoid neoplasms present specific chromosomal translocations, therefore molecular biology studies to detect fusion genes are usually essential for the diagnosis. When the characteristics of the sample are not adequate for molecular biology, or no specific alterations are described, an in-depth knowledge of the histology of these lesions is still necessary to decide the most accurate diagnosis.

Differential diagnosis of myxoid soft tissue tumors. Experience in the Clinical University Hospital of Valencia

Soft tissue tumors with myxoid components are often a diagnostic challenge for the pathologist. We retrospectively reviewed 41 cases of soft tissue tumors with myxoid components diagnosed in our center over a five-year period. The most frequent diagnoses were myxofibrosarcoma and myxoid liposarcoma, followed by low-grade fibromyxoid sarcoma, low-grade fibromyxoid tumor and myxoid neurofibroma. Other diagnoses included were extraskeletal myxoid chondrosarcoma, myxoinflammatory fibroblastic sarcoma, low-grade myxoliposarcoma, myofibrosarcoma, fibromatosis, solitary fibrous tumor, non-ossifying variant of ossifying fibromyxoid tumor and ancient neurinoma with myxoid degeneration. Immunohistochemical and molecular biology studies contributed significantly to the diagnosis. We highlight the importance of immunohistochemistry for MUC4 in the diagnosis of low-grade fibromyxoid sarcoma, and underscore the need for molecular studies in selected cases. Furthermore, several myxoid neoplasms present specific chromosomal translocations, therefore molecular biology studies to detect fusion genes are usually essential for the diagnosis. When the characteristics of the sample are not adequate for molecular biology, or no specific alterations are described, an in-depth knowledge of the histology of these lesions is still necessary to decide the most accurate diagnosis.(AU)

Los tumores de tejidos blandos con un componente mixoide son con frecuencia un desafío diagnóstico para el patólogo. Revisamos retrospectivamente un total de 41 casos de tumores mixoides diagnosticados en nuestro centro durante un período de 5 años. Los diagnósticos más frecuentes fueron mixofibrosarcoma y liposarcoma mixoide, seguidos de sarcoma fibromixoide de bajo grado, tumor fibromixoide de bajo grado y neurofibroma mixoide. Otros diagnósticos incluyen condrosarcoma mixoide extraesquelético, sarcoma fibroblástico mixoinflamatorio, mixoliposarcoma de bajo grado, miofibrosarcoma, fibromatosis, tumor fibroso solitario, variante no osificante de tumor fibromixoide osificante y neurinoma antiguo con degeneración mixoide. Los estudios de inmunohistoquímica y de biología molecular contribuyeron significativamente al diagnóstico. Destacamos la importancia de la detección inmunohistoquímica de MUC4 para el diagnóstico de sarcoma fibromixoide de bajo grado y revisamos la necesidad de estudios moleculares en casos seleccionados. Además, algunas neoplasias mixoides presentan translocaciones cromosómicas específicas, por lo que el estudio molecular para detectar genes de fusión suele ser esencial para el diagnóstico. Cuando las características de la muestra no son adecuadas para el estudio de biología molecular, o no hay descritas alteraciones específicas, sigue siendo necesario un conocimiento profundo de la histología de estas lesiones para decidir el diagnóstico más apropiado.(AU)

[Undergraduate Pathology: Video tutorials including digital pathology make teaching more practical and the subject more attractive]. / Anatomía Patológica para el estudiante de Medicina: videotutoriales con integración de Patología digital como una valiosa herramienta para hacer la asignatura más práctica y atractiva.

INTRODUCTION AND OBJECTIVES: Although pathology is one of the cornerstone subjects of the medical curriculum, for many students it can prove too theoretical and remote from clinical relevance. We present the results of a new distance learning project designed to make the teaching of pathology more practical and render the subject more attractive to the medical student. MATERIALS AND METHODS: We developed a teaching programme which included digital pathology images and video tutorials of clinical cases; the students were required to arrive at a final diagnosis. An explanatory video of how biopsies are processed was also included. Twitter was used for rapid interaction with the students. A questionnaire was then completed by the participants evaluating the various aspects of the project. RESULTS: All the students reached a correct diagnosis for the clinical cases. 89% of the participants were extremely satisfied with the project. The majority agreed that the different activities were interesting and useful for improving their understanding of pathology and thus recommended that they should be continued. CONCLUSIONS: Our results support the inclusion of digital pathology into the curriculum together with video tutorials to enhance undergraduate pathology teaching. In the future, such distance learning could prove a useful resource in combination with conventional face-to-face lectures and tutorials.

Anatomía Patológica para el estudiante de Medicina: videotutoriales con integración de Patología digital como una valiosa herramienta para hacer la asignatura más práctica y atractiva / Undergraduate Pathology: Video tutorials including digital pathology make teaching more practical and the subject more attractive

Introducción y objetivo: La asignatura de Anatomía Patológica es fundamental en la formación del estudiante de Medicina. Sin embargo, para muchos estudiantes la asignatura presenta un excesivo contenido teórico, poco trasladable a la práctica clínica. Presentamos los resultados de un proyecto de innovación docente dirigido a facilitar la transmisión del conocimiento a distancia y hacer de la Anatomía Patológica una asignatura más práctica y atractiva para el estudiante de Medicina. Materiales y métodos: Elaboramos material didáctico integrando imágenes de enfermedad digital con videotutoriales para la exposición de casos clínicos donde los alumnos debían llegar al diagnóstico final. Creamos un vídeo explicativo donde exponemos como se procesan las biopsias y utilizamos redes sociales (Twitter) para mantener una comunicación más fluida con los estudiantes. Finalmente, valoramos la percepción del estudiante sobre las actividades realizadas a través de una encuesta. Resultados: Al final de la actividad todos los alumnos resolvieron los casos clínicos y llegaron al diagnóstico correcto de manera exitosa. El 89% de los alumnos mostró un alto nivel de satisfacción con la actividad. Para la mayoría de los participantes la actividad resultó interesante y didáctica, mejorando su experiencia de aprendizaje, por lo que recomendaban mantenerla en el futuro. Conclusiones: Nuestros resultados soportan la integración de la enfermedad digital en combinación con video tutoriales como una herramienta exitosa en el aprendizaje de la Anatomía Patológica. Este modelo podría mantenerse en el futuro como un recurso útil en combinación con el aprendizaje presencial.(AU)

Introduction and objectives: Although pathology is one of the cornerstone subjects of the medical curriculum, for many students it can prove too theoretical and remote from clinical relevance. We present the results of a new distance learning project designed to make the teaching of pathology more practical and render the subject more attractive to the medical student. Materials and methods: We developed a teaching programme which included digital pathology images and video tutorials of clinical cases; the students were required to arrive at a final diagnosis. An explanatory video of how biopsies are processed was also included. Twitter was used for rapid interaction with the students. A questionnaire was then completed by the participants evaluating the various aspects of the project. Results: All the students reached a correct diagnosis for the clinical cases. 89% of the participants were extremely satisfied with the project. The majority agreed that the different activities were interesting and useful for improving their understanding of pathology and thus recommended that they should be continued.Conclusions: Our results support the inclusion of digital pathology into the curriculum together with video tutorials to enhance undergraduate pathology teaching. In the future, such distance learning could prove a useful resource in combination with conventional face-to-face lectures and tutorials.(AU)

Automated Whole-Liver MRI Segmentation to Assess Steatosis and Iron Quantification in Chronic Liver Disease.

Background Standardized manual region of interest (ROI) sampling strategies for hepatic MRI steatosis and iron quantification are time consuming, with variable results. Purpose To evaluate the performance of automatic MRI whole-liver segmentation (WLS) for proton density fat fraction (PDFF) and iron estimation (transverse relaxometry [R2*]) versus manual ROI, with liver biopsy as the reference standard. Materials and Methods This prospective, cross-sectional, multicenter study recruited participants with chronic liver disease who underwent liver biopsy and chemical shift-encoded 3.0-T MRI between January 2017 and January 2021. Biopsy evaluation included histologic grading and digital pathology. MRI liver sampling strategies included manual ROI (two observers) and automatic whole-liver (deep learning algorithm) segmentation for PDFF- and R2*-derived measurements. Agreements between segmentation methods were measured using intraclass correlation coefficients (ICCs), and biases were evaluated using Bland-Altman analyses. Linear regression analyses were performed to determine the correlation between measurements and digital pathology. Results A total of 165 participants were included (mean age ± standard deviation, 55 years ± 12; 96 women; 101 of 165 participants [61%] with nonalcoholic fatty liver disease). Agreements between mean measurements were excellent, with ICCs of 0.98 for both PDFF and R2*. The median bias was 0.5% (interquartile range, -0.4% to 1.2%) for PDFF and 2.7 sec-1 (interquartile range, 0.2-5.3 sec-1) for R2* (P < .001 for both). Margins of error were lower for WLS than ROI-derived parameters (-0.03% for PDFF and -0.3 sec-1 for R2*). ROI and WLS showed similar performance for steatosis (ROI AUC, 0.96; WLS AUC, 0.97; P = .53) and iron overload (ROI AUC, 0.85; WLS AUC, 0.83; P = .09). Correlations with digital pathology were high (P < .001) between the fat ratio and PDFF (ROI r = 0.89; WLS r = 0.90) and moderate (P < .001) between the iron ratio and R2* (ROI r = 0.65; WLS r = 0.64). Conclusion Proton density fat fraction and transverse relaxometry measurements derived from MRI automatic whole-liver segmentation (WLS) were accurate for steatosis and iron grading in chronic liver disease and correlated with digital pathology. Automated WLS estimations were higher, with a lower margin of error than manual region of interest estimations. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Moura Cunha and Fowler in this issue.

Digital Pathology Enables Automated and Quantitative Assessment of Inflammatory Activity in Patients with Chronic Liver Disease.

Traditional histological evaluation for grading liver disease severity is based on subjective and semi-quantitative scores. We examined the relationship between digital pathology analysis and corresponding scoring systems for the assessment of hepatic necroinflammatory activity. A prospective, multicenter study including 156 patients with chronic liver disease (74% nonalcoholic fatty liver disease-NAFLD, 26% chronic hepatitis-CH etiologies) was performed. Inflammation was graded according to the Nonalcoholic Steatohepatitis (NASH) Clinical Research Network system and METAVIR score. Whole-slide digital image analysis based on quantitative (I-score: inflammation ratio) and morphometric (C-score: proportionate area of staining intensities clusters) measurements were independently performed. Our data show that I-scores and C-scores increase with inflammation grades (p < 0.001). High correlation was seen for CH (ρ = 0.85-0.88), but only moderate for NAFLD (ρ = 0.5-0.53). I-score (p = 0.008) and C-score (p = 0.002) were higher for CH than NAFLD. Our MATLAB algorithm performed better than QuPath software for the diagnosis of low-moderate inflammation (p < 0.05). C-score AUC for classifying NASH was 0.75 (95%CI, 0.65-0.84) and for moderate/severe CH was 0.99 (95%CI, 0.97-1.00). Digital pathology measurements increased with fibrosis stages (p < 0.001). In conclusion, quantitative and morphometric metrics of inflammatory burden obtained by digital pathology correlate well with pathologists' scores, showing a higher accuracy for the evaluation of CH than NAFLD.

Molecular profiling of advanced solid tumours. The impact of experimental molecular-matched therapies on cancer patient outcomes in early-phase trials: the MAST study.

INTRODUCTION: Molecular-matched therapies have revolutionized cancer treatment. We evaluated the improvement in clinical outcomes of applying an in-house customized Next Generation Sequencing panel in a single institution. METHODS: Patients with advanced solid tumors were molecularly selected to receive a molecular-matched treatment into early phase clinical trials versus best investigators choice, according to the evaluation of a multidisciplinary molecular tumor board. The primary endpoint was progression-free survival (PFS) assessed by the ratio of patients presenting 1.3-fold longer PFS on matched therapy (PFS2) than with prior therapy (PFS1). RESULTS: Of a total of 231 molecularly screened patients, 87 were eligible for analysis. Patients who received matched therapy had a higher median PFS2 (6.47 months; 95% CI, 2.24-14.43) compared to those who received standard therapy (2.76 months; 95% CI, 2.14-3.91, Log-rank p = 0.022). The proportion of patients with a PFS2/PFS1 ratio over 1.3 was significantly higher in the experimental arm (0.33 vs 0.08; p = 0.008). DISCUSSION: We demonstrate the pivotal role of the institutional molecular tumor board in evaluating the results of a customized NGS panel. This process optimizes the selection of available therapies, improving disease control. Prospective randomized trials are needed to confirm this approach and open the door to expanded drug access.

Cutaneous Lymphadenoma Is a Distinct Trichoblastoma-like Lymphoepithelial Tumor With Diffuse Androgen Receptor Immunoreactivity, Notch1 Ligand in Reed-Sternberg-like Cells, and Common EGFR Somatic Mutations.

The term "cutaneous lymphadenoma" was coined in this journal for an unusual lymphoepithelial cutaneous adnexal neoplasm, possibly with immature pilosebaceous differentiation. Some authors further proposed that cutaneous lymphadenoma was an adamantinoid trichoblastoma. However, although a hair follicle differentiation is widely accepted, the fact that this is a lymphoepithelial tumor is not appropriately explained by the trichoblastoma hypothesis. Our goal was to further clarify the phenotypic and genotypic features of cutaneous lymphadenoma in a series of 11 cases. Histologically, a lobular architecture surrounded by a dense fibrous stroma was present in all cases. The lobules were composed of epithelial cells admixtured with small lymphocytes and isolated or clustered large Reed-Sternberg-like (RS-L) cells. The epithelial cells were diffusely positive for the hair follicle stem cell markers CK15, PHLDA1, and for androgen receptor. No immunostaining for markers of sebaceous differentiation was found. Intraepithelial lymphocytes were predominantly CD3+, CD4+, FoxP3+ T cells. RS-L cells showed both strong Jagged-1 and Notch1 cytoplasmic immunostaining. Androgen-regulated NKX3.1 nuclear immunostaining was present in a subset of large intralobular cells in all cases. Double immunostaining showed coexpression of NKX3.1 and CD30 in a subset of RS-L cells. No immunostaining for lymphocytic or epithelial markers was present in RS-L cells. EGFR, PIK3CA, and FGFR3 somatic mutations were found by next-generation sequencing in 56% of the cases. We consider that cutaneous lymphadenoma is a distinct benign lymphoepithelial tumor with androgen receptor and hair follicle bulge stem cell marker expression, RS-L cell-derived Notch1 ligand, and common EGFR gene mutations.

Circulating Tumor DNA Detection by Digital-Droplet PCR in Pancreatic Ductal Adenocarcinoma: A Systematic Review.

Pancreatic cancer (PC) is one of the most devastating malignant tumors, being the seventh leading cause of cancer-related death worldwide. Researchers and clinicians are endeavoring to develop strategies for the early detection of the disease and the improvement of treatment results. Adequate biopsy is still challenging because of the pancreas's poor anatomic location. Recently, circulating tumor DNA (ctDNA) could be identified as a liquid biopsy tool with huge potential as a non-invasive biomarker in early diagnosis, prognosis and management of PC. ctDNA is released from apoptotic and necrotic cancer cells, as well as from living tumor cells and even circulating tumor cells, and it can reveal genetic and epigenetic alterations with tumor-specific and individual mutation and methylation profiles. However, ctDNA sensibility remains a limitation and the accuracy of ctDNA as a biomarker for PC is relatively low and cannot be currently used as a screening or diagnostic tool. Increasing evidence suggests that ctDNA is an interesting biomarker for predictive or prognosis studies, evaluating minimal residual disease, longitudinal follow-up and treatment management. Promising results have been published and therefore the objective of our review is to understand the current role and the future perspectives of ctDNA in PC.

Digital pathology: accurate technique for quantitative assessment of histological features in metabolic-associated fatty liver disease.

BACKGROUND: Histological evaluation of metabolic-associated fatty liver disease (MAFLD) biopsies is subjective, descriptive and with interobserver variability. AIMS: To examine the relationship between different histological features (fibrosis, steatosis, inflammation and iron) measured with automated whole-slide quantitative digital pathology and corresponding semiquantitative scoring systems, and the distribution of digital pathology measurements across Fatty Liver Inhibition of Progression (FLIP) algorithm and Steatosis, Activity and Fibrosis (SAF) scoring system METHODS: We prospectively included 136 consecutive patients who underwent liver biopsy for MAFLD at three Spanish centres (January 2017-January 2020). Biopsies were scored by two blinded pathologists according to the Non-alcoholic Steatohepatitis (NASH) Clinical Research Network system for fibrosis staging, the FLIP/SAF classification for steatosis and inflammation grading and Deugnier score for iron grading. Proportionate areas of collagen, fat, inflammatory cells and iron deposits were measured with computer-assisted digital image analysis. A test-retest experiment was performed for precision repeatability evaluation. RESULTS: Digital pathology showed strong correlation with fibrosis (r = 0.79; P < 0.001), steatosis (r = 0.85; P < 0.001) and iron (r = 0.70; P < 0.001). Performance was lower when assessing the degree of inflammation (r = 0.35; P < 0.001). NASH cases had a higher proportion of collagen and fat compared to non-NASH cases (P < 0.005), whereas inflammation and iron quantification did not show significant differences between categories. Repeatability evaluation showed that all the coefficients of variation were ≤1.1% and all intraclass correlation coefficient values were ≥0.99, except those of collagen. CONCLUSION: Digital pathology allows an automated, precise, objective and quantitative assessment of MAFLD histological features. Digital analysis measurements show good concordance with pathologists´ scores.

Neoadjuvant treatment for locally advanced unresectable and borderline resectable pancreatic cancer: oncological outcomes at a single academic centre.

INTRODUCTION: Pancreatic cancer (PC), even in the absence of metastatic disease, has a dismal prognosis. One-third of them are borderline resectable (BRPC) or locally advanced unresectable PC (LAUPC) at diagnosis. There are limited prospective data supporting the best approach on these tumours. Neoadjuvant chemotherapy (ChT) is being increasingly used in this setting. METHODS: This is a retrospective series of consecutive patients staged as BRPC or LAUPC after discussion in the multidisciplinary board (MDB) at an academic centre. All received neoadjuvant ChT, followed by chemoradiation (ChRT) in some cases, and those achieving enough downstaging had a curative-intent surgery. Descriptive data about patient's characteristics, neoadjuvant treatments, toxicities, curative resections, postoperative complications, pathology reports and adjuvant treatment were collected. Overall survival (OS) and progression-free survival was calculated with Kaplan-Meier method and log-rank test. RESULTS: Between August 2011 and July 2019, 49 patients fulfilled the inclusion criteria, and all of them received neoadjuvant ChT. Fluorouracil+folinic acid, irinotecan and oxaliplatin was the most frequently used scheme (77%). The most prevalent grade 3 or 4 toxicities were neutropenia (26.5%), neurotoxicity (12.2%), diarrhoea (8.2%) and nausea (8.2%). 18 patients (36.7%) received ChRT thereafter. In total, 22 patients (44,9%) became potentially resectable and 19 of them had an R0 or R1 pancreatic resection. One was found to be unresectable at surgery and two refused surgery. A vascular resection was required in 7 (35%). No postoperative deaths were observed. Postoperative ChT was given to 12 (66.7%) of resected patients. Median OS of the whole cohort was 24,9 months (95% CI 14.1 to 35.7), with 30.6 months for resected and 13.1 months for non-resected patients, respectively (p<0.001). CONCLUSION: A neoadjuvant approach in BRPC and LAUPC was well tolerated and allowed a curative resection in 38.8% of them with a potential improvement on OS.

Imbalance of immunological synapse-kinapse states reflects tumor escape to immunity in glioblastoma.

Since the proper activation of T cells requires the physical interaction with target cells through the formation of immunological synapses (IS), an alteration at this level could be a reason why tumors escape the immune response. As part of their life cycle, it is thought that T cells alternate between a static phase, the IS, and a dynamic phase, the immunological kinapse (IK), depending on high or low antigen sensing. Our investigation performed in tissue samples of human glioma shows that T cells are able to establish synapsing interactions not only with glioma tumorigenic cells, but also with stromal myeloid cells. Particularly, the IS displaying a T cell receptor-rich (TCR-rich) central supramolecular activation cluster (cSMAC) is preferentially established with stromal cells, as opposed to malignant cells. Conversely, T cells in the malignant areas showed distinct morphometric parameters compared with nonneoplastic tissue - the former characterized by an elongated shape, well-suited to kinaptic dynamics. Importantly, high-resolution 3-dimensional analyses demonstrated the existence of bona-fide IK preferentially arranged in malignant areas of the tumor. This imbalance of IS/IK states between these 2 microenvironments reveals the low antigenic sensing of T cells when patrolling tumorigenic cells and reflects the immunoevasive environment of the tumor.

Sarcoma fibromixoide de bajo grado, un diagnóstico diferencial esencial en los tumores mixoides de apariencia benigna / Low-grade fibromyxoid sarcoma, an essential differential diagnosis in myxoid tumors with benign appearance

El sarcoma fibromixoide de bajo grado es una neoplasia poco frecuente que afecta preferentemente a adultos jóvenes. Se trata de un tumor fibroblástico de apariencia engañosamente benigna que puede presentar recurrencias locales y metástasis a distancia tardías. Presentamos el caso de una niña de 11 años que presentaba una lesión en el muslo, de la que se realizó exéresis completa. El estudio histológico mostró una neoplasia bien delimitada de estroma mixoide, con celularidad fusiforme sin atipia ni mitosis. La expresión inmunohistoquímica de MUC4, junto con el estudio de biología molecular que detectó la expresión del gen de fusión FUS-CREB3L2, confirmaron el diagnóstico de sarcoma fibromixoide de bajo grado. Revisamos el diagnóstico diferencial de los tumores mixoides de partes blandas, especialmente los de apariencia benigna, destacando la importancia del estudio inmunohistoquímico y molecular para descartar el sarcoma fibromixoide de bajo grado

Low-grade fibromyxoid sarcoma is a rare neoplasm, primarily affecting young adults. It is a fibroblastic tumor with a deceptively benign appearance, which may produce local recurrences and late distant metastases. We present a case of an 11-year-old girl with a lesion on her thigh that was completely excised. Histopathology revealed a well-delimited neoplasm with myxoid stroma and fusiform cellularity without atypia or mitosis. Immunohistochemical expression of MUC4, together with molecular biology, which detected FUS-CREB3L2 fusion gene expression, confirmed the diagnosis of low-grade fibromyxoid sarcoma. We review the differential diagnosis of soft-tissue myxoid tumors, especially those with a benign appearance, highlighting the importance of immunohistochemical and molecular studies to rule out low-grade fibromyxoid sarcoma

[Low-grade fibromyxoid sarcoma, an essential differential diagnosis in myxoid tumors with benign appearance]. / Sarcoma fibromixoide de bajo grado, un diagnóstico diferencial esencial en los tumores mixoides de apariencia benigna.

Low-grade fibromyxoid sarcoma is a rare neoplasm, primarily affecting young adults. It is a fibroblastic tumor with a deceptively benign appearance, which may produce local recurrences and late distant metastases. We present a case of an 11-year-old girl with a lesion on her thigh that was completely excised. Histopathology revealed a well-delimited neoplasm with myxoid stroma and fusiform cellularity without atypia or mitosis. Immunohistochemical expression of MUC4, together with molecular biology, which detected FUS-CREB3L2 fusion gene expression, confirmed the diagnosis of low-grade fibromyxoid sarcoma. We review the differential diagnosis of soft-tissue myxoid tumors, especially those with a benign appearance, highlighting the importance of immunohistochemical and molecular studies to rule out low-grade fibromyxoid sarcoma.