The Journal of Pathology

Introduction Conjunctival melanoma (CM) is a rare cancer with a potentially high recurrence rate. The mechanics of its progression, its relationship with neighboring tissues, and its molecular characteristics are largely unknown. Diagnosis currently requires a biopsy and the time and expertise of a pathologist. Methods Archived human biopsies containing CM were submitted to Xenium spatial transcriptomic analysis. Regions were graded by disease progression through histopathology. Differential expression (DE) and composition analysis were performed across disease states. Results From three patients, 12 formalin-fixed paraffin-embedded (FFPE) tissue specimens were recovered. Composition analysis showed that melanoma depletes fibroblast and epithelial cells while melanocytes proliferate. DE signatures specific to each state show a clear pattern of progression from inflammation, to cellular restructuring, and then to tumor progression and malignancy. Conclusion Spatial transcriptomics allows single-cell transcriptomics techniques to compare spatially relevant annotations that are difficult to separate by library. This study proposes disease progression biomarker candidates that may elucidate the mechanics of CM progression and function as objective diagnostic and prognostic tools in the future.

PurposeOvarian clear cell carcinoma (OCCC) is strongly associated with endometriosis and shows geographic variation in incidence. We investigated whether OCCC and adjacent endometriosis exhibit distinct transcriptional states and whether these patterns differ between United Kingdom (UK) and Japanese cohorts. Experimental DesignWe performed whole-transcriptome spatial profiling on specimens from 16 OCCC cases (8 UK, 8 Japan) in which tumor and endometriosis were both present. Gene expression was analyzed in tumor, endometriosis and stroma. ARID1A status was assessed by immunohistochemistry. ResultsMedian age was 59 years (range 26-82). 13/16 cases (81.3%) had early-stage disease. Tissue compartment rather than cohort of origin was the dominant source of variation across endometriosis and tumor regions. Endometriosis was enriched for inflammatory and immune-related pathways compared to tumor, whilst there was greater representation of chromatin and protein-DNA complex assembly pathways in tumor regions. These patterns were conserved across both cohorts and after stratification by ARID1A status. Mesenchymal-associated gene expression scores also significantly differed across stroma, endometriosis and tumor with clear compartmental separation. Cell type deconvolution analyses showed clear compositional differences between stromal and epithelial disease compartments. ConclusionsOCCC and coexisting endometriosis are transcriptionally distinct, with the dominant contrast being compartmental rather than geographic. ARID1A alone is unlikely to account for the principal spatial transcriptional states identified here. Further analyses will be required to ascertain whether these differences reflect genuine biological differences between OCCC and coexisting endometriosis or represent different stages of endometriosis-associated tumorigenesis. Translational RelevanceOvarian clear cell carcinoma often arises in association with endometriosis, yet the biological transition between these lesions remains poorly understood. Using spatial transcriptomics in matched tumor and adjacent endometriosis from Japanese and UK cohorts, we showed that endometriosis is characterized by inflammatory and antigen-presentation features, whereas tumor regions showed chromatin-organization and oncogenic transcriptional states. These patterns were largely maintained irrespective of ARID1A status and geographic background. In addition, spatial deconvolution suggested differences in local immune composition, with tumor regions showing relatively greater neutrophil- and T cell-associated signals. Together, our data suggest that OCCC and coexisting endometriosis share a spatially linked tissue context, but that tumor regions have distinct transcriptional profile and microenvironment that may be involved in the malignant transformation and inform interpretation of molecular classification in endometriosis-associated OCCC.

BackgroundFibrosis and tumor innervation are two features of the tumor microenvironment (TME) that contribute directly to the lethality of pancreatic ductal adenocarcinoma (PDAC), but their potential interactions have not been explored. Moreover, although it is known that activated Schwann cells (SCs) stimulate cancer cell invasion, it remains unclear how SCs are activated. ObjectiveWe determined how SCs are activated in the pancreatic fibrotic microenvironment. DesignThe correlation between physical features of the microenvironment and SC activation was assessed in human patient samples and in mice by SC c-Jun phosphorylation monitoring, atomic force microscopy and multiphoton live imaging. Several in vitro models in which forces were applied to SCs expressing a reporter for c-Jun phosphorylation and RNA-Seq analysis were used to decipher the cellular and molecular mechanisms of SC activation. ResultsNerves surrounded by stiff stroma present higher SC activation. Intravital imaging shows a matrix dependent SC activation. Mechanical forces on SCs induce c-Jun phosphorylation in SCs in a non-canonical manner that involves a nuclear sensing machinery with the proinflammatory enzyme Phospholipase A2. ConclusionFibrosis enhances the protumorigenic impact of innervation by activating SCs via a mechanism in which nuclear compression triggers non-canonical activation of the AP-1 transcription factor complex. Pancreatic fibrosis alone, without cancer cells, is sufficient to activate SCs, suggesting this mechanism may be common across non-malignant pancreatic diseases. Notably, SCs are more sensitive to mechanical activation than PDAC cells. These findings reveal TME interactions that may guide future microenvironment-targeted PDAC therapies. What is already known on this topicThe pancreatic cancer tumor microenvironment is highly innervated and fibrotic, two components of the tumor microenvironment that regulate tumorigenesis. How they impact each other is unknown. Schwann cells have emerged as a significant protumorigenic player, but the triggers of Schwann cell activation remain undefined. What this study addsWe establish that fibrosis induces Schwann cell activation and characterize the mechanism by which it occurs. We uncovered a mechanical mode of action that deforms nuclear membrane and activates c-Jun in Schwann cells, which contradicts the traditional view of c-Jun activation through a stimulus detected at the plasma membrane. How this study might affect research, practice or policyThis study provides a better understanding of the biology of pancreatic ductal adenocarcinoma and supports the development of novel precision therapies that target the fibrotic microenvironment to impact the protumorigenic effect of tumor innervation.

Introduction. TAC/SARIFA has been introduced as a new robust and easy-to-evaluate biomarker in several cancer entities, including colorectal cancer. It is defined by direct contact between at least five tumour cells and one adipocyte and is believed to indicate metabolic reprogramming associated with adverse outcome. However, the mechanism that leads to TAC/SARIFA positivity remains unclear. To investigate whether there is an individual component, we conducted a study on double and triple cancers, establishing a within patient design. Methods. We retrospectively analysed a total of 135 cases with 276 colorectal cancers from two academic medical centres. The TAC/SARIFA status was evaluated, as were the basic histopathological factors. The median follow-up time was 120 months. Results. Cases with any TAC/SARIFA positive tumours showed significantly reduced overall survival (62 vs. 88 months; p = 0.011). Analysing the entire cohort, the rates of concordant and discordant cases followed a random distribution. However, restricting the analysis to synchronous pT3/4 cases revealed a significant deviation from a random distribution (p = 0.016). Conclusion. This study reveals significant concordance of TAC/SARIFA status in synchronous locally advanced colorectal double/triple carcinomas, supporting the concept that tumour adipocyte interaction reflects a host related microenvironmental condition linked to metabolic reprogramming rather than a purely tumour intrinsic event.

Background: Single cell RNA sequencing provides a wealth of information to explore the complexities of the tumour microenvironment, but crucially the spatial topology of the tumour is lost and studying cellular interactions is limited. Spatial transcriptomics aims to address this however the technique remains cost prohibitive for the generation of data from meaningfully-sized clinical cohorts. In contrast, spatial proteomic profiling with multiplex immunofluorescence, preserves spatial interactions, is relatively cost accessible, and is scalable for large clinical cohorts to address powerful translational questions. Whilst multiplex approaches have advanced in recent years, we note that cancer-associated fibroblasts (CAFs) have been explored in less detail, potentially due to difficulties associated with CAF heterogeneity and the diversity of markers used to define them. Methods: We designed, optimised, and validated a multiplex immunofluorescence panel that combines four frequently used CAF markers; alpha smooth muscle actin (aSMA), fibroblast activation protein (FAP), podoplanin (PDPN) and platelet-derived growth factor receptor alpha (PDGFRa) with CD8 and pan-cytokeratin. Here we share our methodology and the practical considerations taken to inform the final panel design. We also highlight the benefits of robust optimisation experiments.

Structural AbstractO_ST_ABSBackgroundC_ST_ABSTriple-negative breast cancer (TNBC) represents a major clinical challenge due to its aggressiveness, heterogeneity and limited availability of effective targeted therapy. We investigated whether LRP-1, a multifunctional cell-surface endocytic and signaling receptor, contributes to TNBC progression. MethodsUsing CRISPR-Cas9, LRP-1-deficient murine 4T1 and human HS578-T TNBC cells were used. Functional consequences were assessed through migration, invasion, and 3D spheroid assays, imaging of focal adhesions and actin organization, atomic force microscopy, and plasmin activity assays. Global molecular reprogramming was analyzed by label-free quantitative proteomics and secretomics. LRP-1-deficient or proficient 4T1 cells were implanted orthotopically in immunocompetent mice; tumor progression was monitored longitudinally while peritumoral collagen architecture and immune microenvironment composition were characterized by second harmonic generation imaging and immunohistochemistry. ResultsWe show that LRP-1 loss reduces TNBC aggressiveness, as reflected by decreased migration and invasive capacity, reduced spheroid evasion, and significant morphological changes in focal adhesion and actin structure. LRP-1-deficient cells became stiffer and showed lower LOXL-4 levels, while pericellular proteolytic activity remained unchanged, suggesting other proteases mechanism. Multi-omic analysis revealed alterations in extracellular matrix (ECM), epithelial-mesenchymal transition, and inflammatory pathways. In vivo, LRP-1-deficiency reduced tumor progression and peritumoral collagen deposition, while increasing CD8+ T and Natural Killer cell infiltration, together with a cytokine profiling compatible with a more immune-permissive microenvironment. ConclusionsLRP-1 act as a key contributor in TNBC progression through matrix remodeling, mechano-adaptation, and immune exclusion. Positioning it as a candidate biomarker for TNBC patients who are likely to benefit from stroma-targeting therapies. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=113 SRC="FIGDIR/small/732906v2_ufig1.gif" ALT="Figure 1"> View larger version (60K): org.highwire.dtl.DTLVardef@1b595c2org.highwire.dtl.DTLVardef@7b208aorg.highwire.dtl.DTLVardef@1956e54org.highwire.dtl.DTLVardef@17e55d0_HPS_FORMAT_FIGEXP M_FIG C_FIG

Background: Breast cancer is the most frequently diagnosed cancer and the leading cause of cancer death in women worldwide, and the great majority of these deaths are caused by metastatic disease. Whether the immunohistochemical (IHC) phenotype of breast cancer is associated with the anatomical site of metastasis has been characterized mainly in high-income, registry-based populations, while data from ecologically stressed and medically under-served regions such as the Lower Aral Sea basin are lacking. Methods: We retrospectively reviewed 652 women diagnosed with breast cancer at the Khorezm Branch of the Republican Specialized Scientific-Practical Medical Center of Oncology and Radiology (Uzbekistan) between 2020 and 2024, of whom 213 had metastatic disease (306 metastatic foci). Histological type was assessed on hematoxylin-eosin and van Gieson-stained sections; quantitative morphometry was performed in Fiji/ImageJ; and HER2, estrogen receptor (ER), progesterone receptor (PR) and Ki-67 were assessed by IHC. The association between marker expression and metastatic site (liver, lung, lymph node) was tested in 187 foci with adequate tissue using the chi-square test, with significance at p < 0.05. Results: Invasive ductal carcinoma predominated. Metastatic site was significantly associated with the IHC phenotype. Liver metastases showed the highest frequency of HER2 3+ (45.7%), ER-negativity (65.2%), PR-negativity (69.6%) and high proliferation (Ki-67 [&ge;] 60%; 47.8%), whereas lymph-node metastases were more often hormone-receptor-positive (ER+ 58.7%; PR+ 52.4%) with lower HER2 3+ (22.2%); lung metastases were intermediate (all p < 0.05). The combination of HER2 3+ and Ki-67 [&ge;] 60% was associated with multi-organ spread. Morphometry corroborated these patterns: liver lesions had larger atypical cells (up to 132.8 m), a higher nuclear-to-cytoplasmic ratio (0.76 vs 0.51) and more extensive necrosis and microvascularity than lymph-node lesions. A pragmatic 5-criterion morphological score (histological type, Ki-67, HER2, ER/PR status, atypical-cell size) stratified metastatic risk into three tiers. Conclusions: In this regional cohort, the IHC phenotype of breast cancer tracked the anatomical site of metastasis, with an aggressive HER2-driven, hormone-receptor-negative profile concentrated in liver metastases and a hormone-receptor-positive profile in lymph-node metastases. These findings reproduce established organotropism patterns in a previously uncharacterized population and support phenotype-aware, site-specific surveillance together with a low-cost morphological risk score for resource-limited settings.

Pancreatic ductal adenocarcinoma (PDAC) is currently the third leading cause of cancer-related deaths in the United States. Intraductal papillary mucinous neoplasms (IPMNs) are neoplastic lesions of ductal origin that seed 10-25% of PDAC. There are currently no markers that distinguish between IPMN that will remain benign and those that will progress to cancer. A heterogenous population of secretory cells, including chemosensory tuft cells and hormone-expressing enteroendocrine cells (EECs), form during metaplasia and neoplastic progression in the pancreas, but the relevance of these populations as it relates to IPMN progression is not well characterized. Here, we performed spatial transcriptomics as well as multiplex immunostaining and spatial statistics on surgically resected IPMN from 60 patients to characterize these populations in all subtypes (gastric foveolar, intestinal, pancreatobiliary) and grades (low-grade, high-grade, invasive). We found that POU2F3+ tuft-like cells, CHGA+ EECs, and a subset of pancreatic endocrine cells ([a] and {gamma} cells) were present in all types of IPMN. Further, serotonin-expressing enterochromaffin cells made up the bulk of EECs in low-grade disease. Enterochromaffin, tuft-like, and glucagon-expressing alpha cells were not evenly distributed and instead were significantly enriched in a spatial manner, which is overlooked using conventional whole tissue quantification approaches. Tuft-like cell clusters were enriched with monocytes and resident memory T cells and anti-correlated to activated fibroblasts (myCAFs, iCAFs). Overall, these secretory cell clusters may reflect clonal expansion resulting in formation of distinct stromal niches with unknown consequences for disease progression.

Background and AimsThe tumor-stroma interface in hepatocellular carcinoma (HCC) harbors critical intercellular interactions that shape immune evasion and treatment response, yet its spatial architecture remains poorly characterized across etiologies. Whether hepatitis B virus (HBV)-related and non-B non-C (NBNC) HCC share conserved border niche features or exhibit etiology-specific microenvironment programs is unknown. We aimed to spatially resolve the tumor boundary ecosystem and identify etiology-associated signaling networks with translational relevance. Approach and ResultsWe performed 10x Visium spatial transcriptomics on 11 HCC specimens (7 HBV, 4 NBNC) and applied a machine-learning pipeline integrating CancerFinder and SpaceFlow to define tumor, boundary, and stromal domains. Across etiologies, the boundary zone showed a recurrent desmoplastic niche characterized by cancer-associated fibroblast, tumor-associated macrophage, and tumor endothelial cell accumulation with collagen-integrin extracellular matrix remodeling, including COL1A1-ITGA11 and COL4A1-ITGAV. Etiology-associated differences were observed in the organization of border-zone signaling programs. In representative HBV-related sections, CCL19-CCR7 signaling showed a comparatively restricted, endothelial-skewed topology, whereas representative NBNC sections showed broader inflammatory ligand-receptor networks with elevated NF-kB-associated pathway activity. ConclusionsThe HCC tumor-stroma border harbors a recurrent desmoplastic niche upon which etiology-associated immune regulatory programs may be superimposed. These findings generate spatial hypotheses relevant to etiology-informed biomarker development and future therapeutic stratification.

Basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (SCC) are the most common keratinocyte-derived malignancies, yet they differ markedly in invasiveness, metastatic potential, and immune contexture. Although cancer-associated fibroblasts (CAFs) are increasingly recognized as key regulators of tumor architecture and tumor immunity, the spatial organization of distinct CAF subtypes in cutaneous carcinomas and their functional relationship with immune cells remains incompletely understood. Using a 33-plex imaging mass cytometry (IMC) panel, we profiled 28 regions of interest (ROIs) from 17 human BCC and SCC specimens, encompassing more than 739,000 single cells, and integrated these data with RNA fluorescence in situ hybridization (RNA-FISH), immunohistochemistry (IHC), multiplex immunofluorescence, and in vitro functional assays. We identified four fibroblast populations, including immunomodulatory CAFs (iCAFs), matrix CAFs (mCAFs), myofibroblast-like CAFs (myoCAFs), and reticular fibroblasts (retFIBs), and found that aggressive tumor subtypes were characterized by increased stromal area, extracellular matrix deposition, and altered CAF composition. CAF composition differed most prominently across BCC subtypes, with nodular BCC enriched for mCAFs and infiltrative BCC showing increased myoCAF density, consistent with a shift toward a contractile stromal program. Spatial analyses revealed distinct CAF-immune niches: iCAFs localized to immune-cell-rich, inflamed niches enriched for activated and/or exhaustion-associated immune-cell marker programs, whereas myoCAFs occupied fibroblast-dense, immune-poor niches with globally reduced immune activation. mCAFs were preferentially associated with immune cell accumulation in the stroma and spatial immune compartmentalization, with limited immune cell presence within tumor nests. At the invasive front, CAF-immune coupling was highly subset-dependent, with iCAFs linked to antigen-experienced T-cell states and myoCAFs linked to immune exclusion. In vitro, patient-derived CAF cultures from myoCAF-rich biopsies showed enhanced collagen-gel contraction, with cultures enriched for MCAM+ CAFs displaying increased contractile capacity. Aggressive tumor variants displayed increased stromal nuclear YAP/TAZ, while complementary single-cell pathway analysis supported a mechanically remodeled stromal microenvironment in which mCAFs contribute ECM/matrix-remodeling programs and RGS5/myoCAF-like populations show enhanced mechanotransduction-associated signaling, rather than a uniform CAF-wide increase in canonical YAP/TAZ transcriptional output. Together, these findings define spatially organized CAF programs in cutaneous carcinomas and identify myoCAF-rich stromal niches as a recurrent feature of aggressive, immune-repressed tumor architecture. These results nominate CAF composition as a biomarker of immune architecture and a potential determinant of therapeutic response.

The spatial arrangement of immune cells in the tumor microenvironment (TME) varies widely, from dispersed to clustered and tumor excluded to infiltrating. Multiplexed spatial profiling is an effective means of characterizing tumor-infiltrating lymphocytes (TILs) and immune complexes such as tertiary lymphoid structures (TLS) in the TME. However, few approaches have been described for objectively parametrizing patterns of immune organization and assessing their association with biological or clinical variables. This makes it difficult to evaluate whether a set of tumors is relatively immunologically cold or hot. Here we describe an intuitive set of statistical tools (available in the R package, tlsR) for characterizing lymphocyte patterns in the TME of solid cancers. We apply tlsR to primary prostate cancer (PCa), which is often described as immunologically cold. Using a cohort of 29 radical prostatectomy specimens stratified into low Gleason-grade (LGG; n=15) and high Gleason-grades (HGG; n =14) we show that HGG PCa is significantly more infiltrated than LGG PCa with lymphocytes organized into B cell or T cell enriched immune clusters (BICs and TICs). A subset of these ICs have the B and T cell zonation and follicular dendritic cells characteristic of a bona fide TLS. HGGs are also enriched with ICs containing precursor exhausted T cells (Tpex) and proliferating B cells and their tumor compartments harbor granzyme-B+ cytotoxic T cells in contact with cancer cells. Thus, far from being cold, a subset of HGG PCa has features associated with active immune surveillance, a finding with implications for emerging PCa immunotherapies.

BackgroundKeratoconus (KC) is a multifactorial disorder with unclear etiology, characterized by localized thinning and a cone-like protrusion of the cornea. The complex etiology of KC exacerbates the lack of an animal model. Previous studies by Tachibana et al. (2002) described an inbred mouse strain (SKC) with a spontaneous, androgen-dependent, cone-like corneal morphology. This study aimed to investigate the corneal phenotypes of SKC mice through an in-depth ophthalmic examination. MethodsMice (n=53) were examined via slit lamp biomicroscopy with fluorescein staining. Spectral-domain optical coherence tomography (SD-OCT) enabled central corneal thickness (CCT) measurement in selected mice (n=26 eyes), and OCT-based pachymetry mapping (n=16 eyes). In vivo corneal confocal microscopy was conducted on eyes to assess cellular morphology (n= 9 eyes). Eyes were collected for histology analysis (n=22). ResultsLesions and epithelial breaks were present in [~]95% of eyes (n=101). Neovascularization, perforation, scarring, and hydrops were seen primarily in males. An opaque, unilateral cone-like morphology was exclusive to males (n=11). Male and female corneas showed no significant difference in CCT, though pachymetry mapping revealed regional thinning patterns in both sexes. Loosened epithelial tight junctions, stromal fibrosis, vascularization, and inflammation of variable severity were identified in both sexes. ConclusionThis study identified previously unreported corneal phenotypes in SKC mice through ophthalmic examination. Unlike previous studies, gross and histological abnormalities were observed in female SKC mice. Our findings suggest a lower penetrance of the cone-like phenotype ([~]20%) than previously reported ([~]33%) and support that the conical phenotype in male mice may be secondary to keratitis.

PurposeTriple-negative breast cancer (TNBC) exhibits substantial clinical heterogeneity, with some patients experiencing early recurrence and poor survival despite similar clinicopathologic features. We sought to determine whether quantitative measures of intratumoral collagen architecture and composition derived from standard histopathologic specimens can identify patients at risk of recurrence and adverse survival outcomes. Experimental DesignWe analyzed a retrospective cohort of 79 TNBC tumors assembled into a tissue microarray using a multimodal computational pathology framework integrating Massons Trichrome staining with COL1 and COL3 immunohistochemistry. Collagen architecture was quantified using fiber-based image analysis and unsupervised clustering, while collagen composition was assessed using a normalized COL3:COL1 ratio. Associations with recurrence-free interval (RFI) and overall survival (OS) were evaluated using Kaplan-Meier analysis, restricted mean survival time (RMST), and Cox proportional hazards modeling. ResultsUnsupervised analysis identified four distinct collagen architectural states, which were consolidated into low-risk and high-risk groups based on recurrence patterns. High-risk collagen architecture was associated with significantly worse long-term RFI (log-rank p=0.025; RMST difference 10.1 months). Independently, a higher COL3:COL1 ratio was associated with improved OS (log-rank p=0.042; RMST difference 9.4 months). Integration of architectural and compositional biomarkers further refined risk stratification, identifying a subgroup with high-risk architecture and low COL3:COL1 ratio that exhibited the poorest survival outcomes. Notably, collagen-based stratification identified patients with divergent outcomes not readily predicted from tumor stage alone. ConclusionsQuantitative assessment of intratumoral collagen architecture and composition provides clinically meaningful prognostic information in TNBC and enables stratification of recurrence and survival risk. These findings support extracellular matrix phenotyping as a practical and scalable computational pathology approach for refining risk assessment in TNBC. Translational RelevanceTriple-negative breast cancer (TNBC) remains clinically challenging due to heterogeneous outcomes that are not fully captured by standard clinicopathologic variables. In this study, we demonstrate that quantitative features of intratumoral collagen architecture and composition, derived from routine pathology specimens, provide clinically meaningful prognostic information. Collagen-based biomarkers, including distinct collagen architectural phenotypes and the COL3:COL1 ratio, identify patient subgroups with distinct recurrence and survival outcomes, particularly among individuals whose risk is not adequately predicted by conventional staging. Importantly, these features can be extracted from widely available histological stains and immunohistochemistry, supporting the potential integration into existing pathology workflows. These findings support the tumor microenvironment as an underutilized source of biomarkers and suggest that extracellular matrix-based phenotyping may improve risk stratification and inform clinical decision-making in TNBC.

Quantifying vascular architecture in histological whole slide images is needed to study tissue organisation, tumour microenvironment biology, and diseaseassociated vascular remodelling. However, vessel analysis in routine immunohistochemistry remains challenging. Available workflows are often manual, require programming expertise, or lack direct integration with digital pathology platforms. We developed VeSpA (Vessel Spatial Analysis), an open-source pipeline and QuPath extension for automated vessel segmentation and morphometric quantification in CD31-stained whole slide images. VeSpA combines configurable signal extraction, using CMYK Yellow channel extraction by default and optional DAB stain deconvolution for H-DAB images, with automatic or percentile-based thresholding, morphological refinement, contour filtering, and lumen filling to generate vessel masks from standard DAB-stained sections. The QuPath extension includes a graphical interface for selecting annotations, TMA cores, or whole images, configuring segmentation parameters, running the Python backend, and importing vessel objects directly into the QuPath hierarchy. For each detected vessel, VeSpA extracts area, major axis length, minor axis length, eccentricity, centroid, and orientation, while also appending summary measurements to parent annotations and TMA cores. Validation against independent pathologist annotations showed that VeSpA achieved segmentation performance close to inter-rater agreement and outperformed yellow channel prompt-based SAM and zero-shot YOLOv8-seg on overlap-based metrics in the tested dataset. VeSpA integrates vessel segmentation, morphometric feature extraction, and QuPath-based visualisation into a single reproducible workflow for vascular quantification in computational pathology and spatial analysis of histological tissue architecture.

Purpose: To characterize peripheral immune alterations in treated birdshot uveitis (BU) patients using high-dimensional mass cytometry and multiplex serology. Design: Cohort study. Subjects: 36 BU patients on immunomodulatory treatment (IMT) and 31 healthy controls (HCs). Methods: Detailed ophthalmologic examinations were performed, and peripheral blood and serum samples were collected for immune profiling using mass cytometry and multiplex cytokine analysis. Main Outcome Measures: Imaging-based indicators of ocular inflammation; peripheral immune cell frequencies; serum cytokine levels. Results: Compared to HCs, BU patients showed increased frequencies of Th17, CD146+ T cells, intermediate effector/central memory T cells co-expressing CXCR3 and CCR4, CD56dim NK cells and elevated IL-18 levels. Patients were clinically stratified by an expert ophthalmologist into three disease activity groups: Inactive, Active (comprising combinations of surface retina, deep retina and choroid activity) and Burned-out. Inactive patients harbored more quiescent effector T cells, e.g. Tim-3+ Tc17-Tc22 intermediates and more CD8+ TSCM, potentially representing a resting pool of autoimmune T cells. Active patients exhibited increased in vivo activation of relevant T cells, with stronger HLA-DR, CD38 or PD-1 expression, and highest levels of CD56dim NK cells. Immune profiles were also linked to treatment subgroups: csDMARDs (conventional synthetic disease-modifying antirheumatic drugs) were associated with higher CD56bright NK frequencies, and absence of therapy showed elevated PD-1/SLAMF7 Tc17+1 and PD-1CD57 CD8 TEMRA cells. IL-6R blockade (tocilizumab) resulted in loss of IL-6R T-cells accompanied by increased SLAMF7 T cells, due to epitope masking. Conclusions: Peripheral CyTOF profiling anchored to thorough clinical stratification revealed disease activity-associated immune signatures and therapy-associated imprints in BU.

Intraductal oncocytic papillary neoplasms (IOPNs) are rare tumors that develop from biliary and pancreatic ductal epithelium and progress to lethal cancers. Human IOPNs and IOPN-associated carcinomas are known to harbor the DNAJB1-PRKACA gene fusion, however the role of the oncogenic fusion in carcinogenesis is poorly understood. We developed a Cre-inducible mouse model of human DNAJB1-PRKACA expression and substantiated that the DNAJB1-PRKACA fusion gene is a bona fide driver of IOPN-associated biliary and pancreatic carcinoma. By analyzing the unique histopathologic and transcriptional changes that occur at each stage of tumor development, we found that these murine tumors closely mimic human DNAJB1-PRKACA driven tumors. Furthermore, we identified that many of the salient features of invasive carcinoma are established at the pre-invasive stage, including evidence of tumor cell metabolic dysregulation, immunosuppressive tumor stroma and expression of genes strongly associated with invasive DNAJB1-PRKACA driven cancer in humans. Finally, we found that Slc16a14, a characteristic DNAJB1-PRKACA regulated super-enhancer associated gene, serves as a robust biomarker of malignant transformation from IOPN to invasive carcinoma.

Pancreatic ductal adenocarcinoma (PDAC) exhibits extensive molecular and microenvironmental heterogeneity, yet how tumor lineage states interact with spatial immune organization in advanced disease remains poorly understood. Here, we performed multiplexed spatial proteomic profiling using tissue cyclic immunofluorescence (t-CyCIF) in 27 patients with advanced PDAC and integrated these analyses with spatial transcriptomic profiling of representative tumors. Tumors were classified into Classical, Hybrid, Basal, and Null epithelial states based on GATA6 and CK5 expression, revealing distinct immune architectures associated with clinical outcome. Classical and Hybrid tumors displayed immune-inflamed microenvironments enriched for lymphocytes, whereas Basal and Null tumors exhibited immune-excluded, macrophage-dominated landscapes characterized by increased M2 macrophages. Spatial transcriptomic analysis further revealed that Hybrid tumors were not homogeneous intermediate states but instead contained spatially segregated Hybrid_Classical and Hybrid_Basal regions with distinct transcriptional programs, immune niches, and cell-cell communication networks. Hybrid_Basal regions were associated with increased M2 macrophage enrichment and preferential activation of macrophage-derived SPP1-CD44 signaling, implicating localized immune-epithelial interactions in epithelial plasticity and lineage-state transitions. To quantify spatial immune organization, we developed a spatial immune score that captures the relative positioning of CD8 cytotoxic T cells with respect to CD4 helper T cells and CD163 M2 macrophages. Higher scores were associated with worse survival and provided stronger prognostic information than conventional immune cell abundance metrics. Integration of the spatial immune score with GATA6 expression achieved superior prognostic discrimination (AUC = 0.822) compared with either feature alone. Together, these findings demonstrate that tumor lineage state and spatial immune organization represent complementary dimensions of PDAC biology and highlight spatial tumor-immune interactions as determinants of clinical outcome in advanced pancreatic cancer. SummaryPancreatic ductal adenocarcinoma (PDAC) exhibits marked molecular and microenvironmental heterogeneity, yet how tumor lineage states interact with the spatial immune microenvironment in advanced disease remains poorly understood. Here, the authors apply multiplexed spatial proteomics and spatial transcriptomics to advanced PDAC and show that epithelial lineage states defined by GATA6 and CK5 are associated with distinct immune architectures and macrophage-enriched signaling niches. Hybrid tumors contain spatially segregated epithelial states with differential immune engagement and SPP1-CD44 signaling. The authors further identify a spatial immune score based on the relative positioning of CD8 T cells, CD4 T cells, and M2 macrophages that predicts patient survival. Integration of spatial immune organization with tumor lineage information improves prognostic stratification, highlighting the clinical relevance of spatial tumor-immune interactions in advanced PDAC.

ObjectivesBenign Prostatic Hyperplasia (BPH) is the non-cancerous enlargement of the prostate accompanied by lower urinary tract symptoms, affecting 50% of men by the age of 501,2. Advanced highly symptomatic BPH exhibits large epithelial glandular nodules with microglandular/atypical adenomatous hyperplasia, but how these features form is unknown3. Our lab has reported that the common parasite Toxoplasma gondii can infect the prostate and induce glandular nodule formation in mice3. The objective of this study is to determine if T. gondii exposure in humans correlates to BPH and nodule formation and if it induces urinary dysfunction concurrent in the mouse model. MethodsWe assessed Toxoplasma exposure by serum ELISA in patients with BPH and non-BPH donor controls, and compared seropositivity rates between the groups. We further assessed the histopathology of these patients for the presence of inflammation and epithelial glandular nodule formation and compared Toxoplasma positive and negative samples. We determined voiding function in Toxoplasma-infected mice between 14 and 60 days of infection with void spot with Void Whizzard software. ResultsMen diagnosed with BPH are more likely to be seropositive for Toxoplasma than age-matched undiagnosed donor controls. In addition, BPH patients that are seropositive for Toxoplasma are more likely to exhibit glandular nodule formation with microglandular / adenomous hyperplasia than seronegative BPH patients. In animal studies, Toxoplasma infection results in abnormal void patterns concurrent with microglandular hyperplasia and nodule formation. ConclusionsThese results suggest that Toxoplasma may be contributing to BPH pathology and lower urinary tract dysfunction in both humans and mice, opening new insights into the development of this important disease. The results also serve to further characterize this model of prostatic hyperplasia and define it as a potential urinary dysfunction model.

The choroid is critical for maintaining vision and implicated in several ocular diseases, being the sole source of nutrients and waste removal for the outer retina. Genetic discovery can help elucidate the pathways through which choroidal features influence disease risk. Our meta-analysis of genome-wide association studies (n= 78,682 participants) identified 30 genomic regions, including 20 novel loci, associated with choroidal thickness. Findings suggest inflammatory and vascular processes drive choroidal thickness, with overlapping mechanisms shared with refractive error. Genome-wide independently significant SNPs accounted for 18.7% of the genetic variance in choroidal thickness. Mendelian randomisation analyses showed a causal effect of age-related macular degeneration on choroidal thickness, and suggest a bidirectional causal effect between choroidal thickness and primary angle-closure glaucoma. These findings provide insight into the shared genetic architecture and biological pathways linking choroidal thickness and related diseases.

Age-related macular degeneration (AMD) shows substantial clinical heterogeneity that remains unexplained despite extensive genetic and clinical characterization. We evaluated whether proteomic stratification could provide insight beyond clinical phenotype and genetic risk. We performed 384-plex plasma proteomics in a cohort of 215 individuals, including patients with early and late neovascular AMD, other complement-associated retinal diseases, and age-matched controls. Proteome-based reclassification identified four disease-overarching clusters. Neovascular AMD cases were partitioned almost exclusively between two clusters (30/36). Early AMD cases were predominantly assigned to one of these clusters (10/18), whereas only two localized to the other (2/18). Both AMD-associated clusters shared elevated levels of a protein module enriched for lipoprotein-related functions compared to the other clusters. However, the cluster containing both early and neovascular AMD cases showed higher levels of additional protein modules enriched for complement pathways and cellular stress-response pathways compared with the other AMD-associated cluster. Importantly, this molecular divergence in neovascular AMD could not be explained by genetic predisposition (i.e., 52-variant AMD genetic risk score), signatures of biological ageing, nor by other clinical features. Together, these findings support two proteomic endotypes of neovascular AMD with distinct involvement of cellular stress pathways.