Granulomatous lobular mastitis (GLM) is a rare, chronic, benign inflammatory disease of the breast with an unclear aetiology. This study aimed to characterise the microbial features of GLM using metagenomic next-generation sequencing (mNGS) and to provide potentially relevant microbial clues for clinical evaluation.
Twenty fresh lesion tissue samples were collected from 15 female patients with GLM, including one representative sample per patient and five additional deep tissue samples. Clinical data collection, mNGS, bioinformatics analysis and data interpretation were performed to characterise the microbial profiles of GLM lesions.
In this study, all patients presented with palpable breast masses, breast pain and abscess formation. More than half showed increased white blood cell counts, neutrophil percentages, C reactive protein levels and erythrocyte sedimentation rates together with decreased lymphocyte percentages. Based on genus-level filtering, mNGS identified 16 bacterial genera, 14 fungal genera and 3 viral genera, revealing a complex but bacteria-dominated microbial profile. The most frequently detected bacterial genera were Corynebacterium, Cutibacterium, Acinetobacter, Staphylococcus and Hathewaya, with marked interpatient variation in relative abundance, while fungal profiles were relatively more concentrated. In five patients with both superficial and deep tissue samples, microbial profiles differed across sampling depths, particularly for bacterial composition.
mNGS revealed a complex, bacteria-dominated microbial profile in GLM lesions and indicated that sampling depth may influence the detected microbial profiles. These findings may provide useful clues for clinical evaluation, but the pathogenic significance of these micro-organisms remains to be elucidated.
This case illustrates sequential transformation from FL to BRAF-mutated HDS with excellent response to BRAF/MEK inhibition, followed by evolution into HGBCL-MYC/BCL2 responding transiently to immunochemotherapy, emphasising the value of repeated histological and molecular reassessment in FL evolution.
]]>The traditional three-level H&E sectioning protocol for prostate biopsies was developed for ultrasound-guided systematic sampling and predates lesion-targeted biopsy approaches. Multiparametrical MRI (mpMRI) has improved detection of clinically significant prostate carcinoma but has also increased biopsy volume, workload, costs and digital pathology requirements, including whole-slide imaging and artificial intelligence (AI) integration.
A retrospective institutional cost-yield analysis was performed on prostate biopsy cases at Beth Israel Deaconess Medical Center (2015–2022), comparing systematic 12-core biopsies with combined systematic and mpMRI-targeted biopsies. Case volume, tissue blocks and H&E slides were analysed. Per-slide costs were calculated, and additional digital pathology and AI workflow costs were estimated using published data and vendor pricing. Case volume increased by 27% over 7 years, while combined systematic and mpMRI-targeted protocols increased tissue blocks and H&E slides by 39%. The cost per H&E slide was $7.18, with digital pathology and AI workflows adding an estimated $4.30–5.00 per slide. In systematic 12-core biopsies, third-level sectioning identified four additional low-volume carcinomas at a cost of $2283 per diagnosis. In combined biopsies, two additional carcinomas were detected exclusively on the third level, both Grade Group 1, with a cost of $27 657 per diagnosis.
Routine three-level H&E sectioning in combined systematic and mpMRI-targeted prostate biopsies demonstrated low incremental diagnostic yield and substantial additional processing cost. A two-level protocol with selective third-level sectioning may preserve detection of clinically significant carcinomas in this institutional cohort, while reducing workload and cost in the digital pathology era.
While kinase-altered spindle cell tumours were classically recognised in paediatric superficial soft tissues, recent literature indicates an expanding clinicopathologic spectrum. This study investigates a cohort of RAF/BRAF-altered mesenchymal tumours to further characterise their presentations in adults, deep-seated/visceral locations, variable immunophenotypes and complex molecular evolution.
Eight molecularly confirmed RAF/BRAF-altered mesenchymal tumours were retrospectively evaluated. Clinical characteristics, histomorphology, immunohistochemistry, targeted next-generation sequencing profiles and follow-up data were comprehensively analysed.
The cohort comprised seven females and one male (median age, 34.5 years). Tumours arose in soft tissues (n=5, including the deep pelvis) and visceral organs (n=3; two breast, one lung). Histologically, the neoplasms exhibited a broad morphologic spectrum: three demonstrated low-grade spindle cell morphology, whereas five displayed high-grade pleomorphic or fibrosarcoma-like features, including one pelvic tumour mimicking myxoid leiomyosarcoma. Immunophenotypes diverged significantly with histologic grade: low-grade tumours retained CD34 and S100 coexpression, whereas high-grade lesions consistently lost both markers, with one case exhibiting focal Desmin positivity. Molecular profiling revealed ubiquitous mitogen-activated protein kinase pathway activation, identifying six kinase gene fusions (including novel IQSEC1::RAF1 and PLEKHH3::BRAF variants) and two BRAF V600E mutations. High-grade tumours frequently harboured concurrent tumour suppressor gene alterations (eg, TP53, PTEN). Notably, one pelvic tumour exhibited a trunk NTRK1 mutation alongside a subclonal BRAF V600E mutation. Notably, despite the alarming high-grade histomorphology in several cases, clinical behaviour remained relatively indolent, with no disease-related deaths to date.
RAF/BRAF-driven mesenchymal tumours possess a broader clinicopathologic spectrum than traditionally recognised, frequently affecting adults and deep/visceral sites. Their inherently variable immunophenotypes and the presence of high-grade morphologic features do not strictly predict an aggressive clinical trajectory. Comprehensive molecular profiling is essential to refine diagnostic criteria, accurately identify these neoplasms, and elucidate the genomic events associated with tumour progression.
Myeloproliferative neoplasms (MPNs) are clonal disorders characterised by excessive proliferation of myeloid lineages. Mutations in MPL exon 10, including p.Trp515Leu and p.Trp515Lys, are recurrent and clinically relevant.
Next-generation sequencing (NGS) offers higher sensitivity, faster turnaround and multiplexing.
DNA was extracted using the Qiagen Gentra PureGene kit and quantified using NanoDrop. MPL exon 10 was amplified using gene-specific primers containing Nextera Read 1 and Read 2 sequences (
Diagnostic pathology is currently experiencing a period of profound technological transformation. Digital slide scanning, artificial intelligence (AI)–assisted image analysis, integrated laboratory information systems and automated workflow solutions are increasingly being introduced into routine practice. These developments hold considerable promise. They may improve efficiency, facilitate remote consultation, support quality assurance and help address the growing imbalance between rising diagnostic workload and the limited number of trained pathologists.
From the perspective of an experienced practising academic pathologist, this question merits careful reflection. The purpose of this essay is not to question the...]]>
To compare changes in HER2 expression status on reassessment across multiple clinical groups using new three-tier versus traditional binary HER2 reporting schemas.
Retrospective study of 1107 paired IBC samples wherein HER2 immunohistochemistry (IHC) and, where needed, in-situ hybridisation (ISH) were performed at least twice in four clinical groups: core needle biopsy (CNB)-upfront resection (n=277); CNB-post-chemotherapy resection (n=104); primary (CNB/resection)-recurrence (local/metastatic, n=702); initial and subsequent distant metastasis (n=24). Concordance was noted for HER2-positive (HER2-IHC 3+ or 2+ ISH-amplified), negative (HER2-IHC 0) and low (HER2-IHC 1+ and 2+ ISH-non-amplified) status, and compared with the concordance of binary HER2 status (positive/negative).
HER2 concordance dropped sharply to 69.7% (k=0.53, 95% CI 0.48 to 0.57) on reassessment after applying the three-tier schema, driven primarily by bidirectional shifts between HER2-negative (IHC 0) and HER2-low. Referral specimens showed poorer concordance than in-house tissue in both binary (p value <0.001, OR: 2.40, 95% CI 1.40 to 4.10) and ternary classification (p value <0.001, OR: 1.72, 95% CI 1.31 to 2.2), emphasising the effects of pre-analytical factors like fixation on HER2 interpretation.
The three-tier HER2-low classification schema demonstrates poor reproducibility on re-evaluation, with nearly one-third of cases discordant. This fluidity has significant therapeutic implications. We recommend HER2 re-evaluation with careful attention to the 0 versus 1+ distinction, especially in metastatic and post-treatment settings and when pre-analytical factors are suboptimal.
Anaplastic thyroid carcinoma (ATC) exhibits limited responsiveness to immunotherapy. The current study characterises the immune cell repertoire in ATC compared with differentiated thyroid carcinoma (DTC) and thyroid follicular nodular disease (TFND) and evaluates IFN- and TGF-β mRNA expression.
Cytotoxic T lymphocytes (CTLs), regulatory T cells (TREGs), natural killer cells (NK), B lymphocytes and myeloid-derived suppressor cells (MDSCs) were analysed by multicolour flow cytometry in prospectively collected ATC, DTC and TFND tissues. IFN- and TGF-β mRNA expression was quantified using RT-PCR.
ATC demonstrated significantly higher MDSC infiltration than DTC or TFND. CTLs were elevated in ATC relative to DTC, while TREGs, NK and B-cells were lower. IFN- and TGF-β expression did not differ significantly although IFN- expression was higher in DTC and ATC than in TFND.
ATC microenvironment is rich in immunosuppressive MDSCs. These findings support MDSC-focused immunomodulation as a promising adjunct therapy in ATC.
Accurate assessment of the Ki-67 proliferation index (PI) is essential for grading and prognostication of gastrointestinal well-differentiated neuroendocrine tumours (NETs). While manual counting (MC) of 500–2000 tumour cells remains the standard, digital image analysis (DIA) offers potential advantages in efficiency and reproducibility. We evaluated the comparability of open-source DIA platforms on camera-captured (CC) images and whole-slide images (WSI) for Ki-67 quantification.
Ki-67 hotspot areas of 70 NETs were photographed using a microscope-mounted camera. PI was determined by MC (gold standard) and compared with automated counts in 68 cases (two excluded owing to high background staining) using QuPath (V.0.4.4). In a randomly selected subset of 20 cases, the same hotspot areas were analysed using ImageJ, ChatGPT V.4.0 (colour-based segmentation) and the IHCexpert.com platform. Additionally, WSI files of these 20 cases were imported into QuPath for DIA; PI of identical areas were compared against static images.
DIA using QuPath (on CC images) demonstrated excellent agreement with MC (intraclass correlation coefficient). Only one case showed grade reclassification (manual G1, 2.92%; DIA G2, 3.38%). In the subset analysis (n=20), comparable Ki-67 indices were observed across all digital platforms and between CC images and WSI. Grade switches from changes in Ki-67 PI were observed in two additional cases (G2 to G1 in IHCexpert.com group and G1 to G2 in ChatGPT group).
Our findings offer the prospect of eliminating variability in the analysis of PI estimation. Of note, CC images yield results similar to WSI, supporting broader applicability in resource-limited practice settings.
The authors calculate an overall concordance of 91.5% and Cohen’s kappa of 0.83 (‘near-perfect’ agreement) using uPath compared with manual scoring with light microscopy as the gold standard (n=106). However, all nine discordant slides were reported as negative by manual scoring (group 5), but positive by uPath (group 1: eight cases, group 4: one case). This results in 100% sensitivity (negative concordance), 85.9% specificity (positive concordance) and positive predictive value of only 82.3%. Gough et al also investigated uPATH concordance, but do not further analyse discordant cases, precluding...]]>
Comparison of immunohistochemical detection of mismatch repair (MMR) proteins within tumours, as deficient MMR is important for (1) the detection of Lynch Syndrome, caused by inherited variants affecting the DNA MMR genes MLH1, MSH2, MSH6 and PMS2, (2) aiding MMR gene variant interpretation and (3) deciding on use of immune checkpoint blockade therapy.
This retrospective analysis compares the performance of different MMR immunohistochemistry (IHC) antibody clones, detection systems and automation IHC platforms using a decade of technical data submitted to the UK National External Quality Assessment Scheme (NEQAS) as part of its MMR EQA programme, with calculation of participants’ final aggregated scores (FAS) for performance comparison.
Between 2011 and 2022, there were 38 MMR assessment runs, with an average of 44.8 submissions per antigen per assessment run. MMR module participation greatly increased over this decade. Average FAS showed a small non-significant upward trend with the lowest scores (14.6) observed in the first half of the decade, with greater concordance between FAS scores (15.1) in the second half of the decade. For MMR IHC, the antibody clones most frequently used were M1 and ES05 (FAS 15.7 and 15.1) for MLH1, G219-1129 and FE11 (FAS 14.8 and 14.1) for MSH2, EP51 and A16-4 (FAS 15.2 and 15.2) for PMS2 and SP93 and EP49 (FAS 16.1 and 15.6) for MSH6. The most common detection systems were Ventana Optiview, Leica BondMax, Leica Bond Refine, Dako FLEX+ and Ventana UltraView.
The quality of submitted MMR IHC sections has risen, with recent assessment scores showing lower variability, indicating better antibody clone performance, improved detection systems and IHC automation platform technology, allied to increasing technical competence among participants. UK NEQAS provides insight and feedback relating to MMR IHC protocols that most reliably produce high-quality MMR IHC staining to facilitate accurate reporting of the increasingly important tumour MMR status.
Current diagnostic criteria for pancreatic serous cystadenocarcinoma (SCC) create a grey zone for tumours that are locally invasive but not yet metastatic. We sought to resolve this ambiguity by defining the clinicopathological features and searching for the malignant potential of this aggressive subset of serous neoplasms.
A combined cohort of 25 patients was compiled from a systematic literature review and augmented with two institutional cases.
Infiltrative growth was a near-universal finding (23/25), often in tumours with a prominent solid architecture. This growth pattern was reflected by frequent local invasion into adjacent organs (40%). The malignant potential of these neoplasms was confirmed by the development of metachronous distant metastases in 28% of patients (median time: 40.5 months) despite their absence at presentation. Our institutional cases highlight the diagnostic value of Ki-67 immunohistochemistry, revealing markedly elevated proliferation indices (5% and 10% in hotspots) that starkly contrast with those of conventional serous cystadenomas (<2%).
Local invasion in serous neoplasms, especially when combined with a solid architecture and high Ki-67 index, defines a high-risk subset highly suspicious for serous cystadenocarcinoma. This interpretation must be balanced against the generally indolent behaviour of most serous neoplasms, and such cases warrant closer clinical surveillance.
We identified a novel fusion of Calcium voltage-gated channel auxiliary subunit gamma 4 and Yes-associated protein 1 (CACNG4::YAP1) in a metastatic brain lesion from a woman in her 60 s with a history of high-grade serous ovarian carcinoma. Histologic sections demonstrated sheets of...]]>
Distinguishing epithelioid malignant mesothelioma (EMM) from poorly differentiated lung adenocarcinoma (PD-LUAD) remains challenging, particularly when 21.7% of PD-LUADs lack lineage-specific markers (thyroid transcription factor-1 (TTF-1)/Napsin A), creating a diagnostic blind spot. While GATA-binding protein 3 (GATA3) is established in sarcomatoid mesothelioma, its complementary diagnostic value and prognostic relevance in EMM are not well defined.
This retrospective study analysed 115 tissue specimens (55 EMMs; 60 PD-LUADs). Immunohistochemistry for GATA3, calretinin, Wilms’ tumour gene 1 (WT-1), TTF-1, Napsin A and pan-cytokeratin was performed. Results were correlated with clinicopathological parameters and overall survival (OS) using Kaplan–Meier and multivariate Cox regression analyses.
GATA3 was expressed in 78.2% of EMM but only 6.7% of PD-LUAD cases (p<0.001). Although not specific enough for standalone diagnosis, GATA3 provided meaningful complementary value: in TTF-1/Napsin A–negative PD-LUAD, GATA3 remained negative in 92.3%, helping to exclude EMM when used within a broader panel. Incorporating GATA3 with calretinin and WT-1 improved panel sensitivity to 96.4% while maintaining 100% specificity.
High GATA3 expression in EMM correlated significantly with advanced T stage, higher International Mesothelioma Interest Group stage and poor functional status (Karnofsky performance status/Eastern Cooperative Oncology Group). Multivariate analysis identified GATA3 expression (p=0.037), smoking (p=0.041) and clinical T stage (p<0.001) as independent predictors of shorter OS. A qualitative inverse relationship between tumorous GATA3 and GATA3-positive tumour-infiltrating lymphocytes was also noted.
GATA3 serves as a useful adjunct within established immunohistochemical panels, particularly in resolving ambiguity in double-negative PD-LUAD. Beyond its supportive diagnostic role, GATA3 demonstrates independent prognostic significance and may reflect underlying immune-microenvironmental features, meriting further exploration in biomarker-guided therapeutic stratification.
Mucinous breast carcinoma (MBC) is a well-recognised special type of invasive breast carcinoma (BC) characterised by abundant extracellular mucin and, in its classical form, a favourable clinical behaviour. However, extracellular mucin production is not unique to classical MBC and extracellular mucin is associated with a spectrum of benign and malignant entities with varying and overlapping morphological patterns but with very different clinical outcomes. Failure to recognise this diversity risks diagnostic imprecision and inappropriate management decisions.
This review adopts a clinicopathological and pathogenetic framework centred on BCs associated with extracellular mucin, using classical low-grade MBC as the prototype lesion. The review integrates available molecular data, clinical outcome studies, observations on associated in situ and precursor lesions and accumulated diagnostic experience to generate conceptual models linking morphology, biology and clinical behaviour. Emphasis is placed on reproducible features relevant to routine diagnostic practice to enable pathologists to resolve a differential diagnosis of breast lesions in core biopsies and resections.
]]>We read with great interest the recent article by Mauri et al
Here, we assessed MTAP and p16 expression by immunohistochemistry in a series of 75 formalin-fixed, paraffin-embedded GBC surgical specimens retrieved from the archives of the Surgical...]]>
In February 2026, the Department of Health and Social Care published the National Cancer Plan for England, a significant cancer policy document.
It is a far-reaching and ambitious plan set out in seven chapters including prevention, screening, genomics, clinical trials, rare cancers and children’s cancer services.
Histopathology has been identified as an impediment to ideal cancer performance and metrics. These expectations are explicitly tied to the cancer plan and a summary pertinent to histopathology is outlined in
Delays...]]>
Although histological criteria underpin current classification, accurate risk stratification, particularly for borderline and malignant tumours, remains challenging.
We analysed a 20-year institutional series of phyllodes tumours (PTs), integrating clinicopathological data with long-term clinical outcomes. Histological features were extracted from original pathology reports, with slide re-review where archival material was available.
Among 111 PTs, 80% were benign, 11% borderline and 9% malignant. The follow-up ranged from 0 to 20 years, with 11.3, 10.3 and 7.6 years for benign, borderline and malignant PT, respectively. Most patients underwent local excision; mastectomy was performed in 22% of malignant PT. Final positive margins were identified in 18% of benign, 8% of borderline and none of the malignant tumours. Adjuvant radiotherapy was administered in 18% of borderline and 67% of malignant PT. Local recurrence occurred in 3%, 11% and 22% of benign, borderline and malignant tumours, respectively. Distant metastases were observed exclusively in malignant PTs (33%, 3/9 cases), two of which were preceded by local recurrence. Notably, two of the three metastatic malignant PTs showed either ≤10 mitoses/10 high-power field or <marked stromal atypia and lack of stromal overgrowth, which are required for diagnosis of malignant PT per WHO 5th edition recommendation. The low event rate precluded robust multivariable analysis.
Our results highlight the biological heterogeneity of malignant PTs and the limitations of rigid histological thresholds. These findings underscore the need for collaborative, multi-institutional prospective studies with standardised tumour sampling and reporting and molecular correlation to refine clinically meaningful risk stratification in PT.
T-cell lymphomas are often histologically indistinguishable from benign T-cell infiltrates. Clonality testing is frequently required for diagnosis. It lacks the spatial context and is slow and expensive, relying on complex multiplexed PCR reactions, interpreted by scientists or pathologists with specialist molecular training. We set out to make monoclonal antibodies to develop a novel immunohistochemical test for T-cell lymphoma, analogous to the kappa/lambda assay for B-cell and plasma cell neoplasms.
We developed a pair of highly specific monoclonal antibodies against the two alternatively used but very similar T-cell receptor β constant regions, TCRβ1 and TCRβ2 (encoded by the TRBC1 and TRBC2 gene segments). We demonstrate the feasibility of immunohistochemical detection of TCRβ1 and TCRβ2 in formalin-fixed, paraffin-embedded tissue as a novel diagnostic strategy for T-cell lymphomas.
Single immunostaining results are presented for 13 T-cell lymphomas and 8 benign T-cell populations, together with illustrative examples of TCRβ1/2 double immunostaining. Finally, we show that this single immunostaining is amenable to automated cell counting, permitting accurate calculation of the TCRβ2:TCRβ1 ratio.
This novel assay can be used in a similar way to the kappa/lambda assay for B-cell and plasma cell neoplasms.
The core issue lies in the interpretation of the variant allele frequency (VAF) within the biological context of the gene’s location. As reported in the article, the two male patients harbouring...]]>
Cell division cycle 25A (CDC25A) is a key regulator of cell cycle progression, DNA replication and apoptosis in cancer cells. This study employed multiple well-characterised breast cancer cohorts to evaluate the prognostic significance of CDC25A and to characterise the molecular association linked to its expression in early-stage breast cancer.
CDC25A transcriptomic expression was systematically assessed for statistical associations with key genes and pathways implicated in cell cycle regulation, DNA damage repair, cyclin-dependent signalling, tumour microenvironment and epithelial–mesenchymal transition. Its prognostic relevance was further evaluated through survival analyses. These investigations were conducted across the Molecular Taxonomy of Breast Cancer International Consortium (n=1980), the Cancer Genome Atlas (n=854) and Kaplan-Meier Plotter (n=4929) breast cancer cohorts. Subsequently, this study explored the associations between CDC25A protein expression and established clinicopathological parameters, molecular characteristics and patient outcomes using immunohistochemistry in a large, well-characterised Nottingham breast cancer cohort (n=1045).
High CDC25A expression was associated with altered expression of key breast cancer-related genes involved in cell cycle control, DNA damage repair, cyclin-dependent signalling, matrix remodelling and epithelial–mesenchymal transition-related biology. Elevated CDC25A expression at both transcriptomic and proteomic levels was significantly associated with aggressive clinicopathological features, including higher tumour grade, larger tumour size, hormone receptor negativity and lymphovascular invasion. High CDC25A protein expression independently predicted poorer survival outcomes (p=0.027; HR 1.28, 95% CI 1.18 to 1.98).
CDC25A is an independent prognostic biomarker of clinical outcome in breast cancer. Further functional studies are warranted to validate CDC25A as a potential prognostic and therapeutic biomarker in breast cancer.
Myeloid neoplasms (MN) with MECOM rearrangements can present either myelodysplastic neoplasms (MDS) or acute myeloid leukaemia (AML), both associated with dismal prognosis. The 2022 WHO classification now defines these as ‘AML with MECOM rearrangements’ regardless of blast counts due to similarly poor outcomes.
Data of newly diagnosed AML patients were obtained from a national registry conducted by the Thai Acute Leukemia Working Group, comprising nine academic and tertiary-care hospitals across Thailand since January 2014. MDS...]]>
Primary cutaneous peripheral T-cell lymphoma, not otherwise specified (pcPTCL-NOS) is a group of T-cell lymphomas that does not fit the criteria of other primary cutaneous T-cell lymphomas (PCTCLs) defined by the WHO. The immunophenotype of the neoplastic T-cells can vary, with some cases showing aberrant expression of CD20. The diagnosis is exceedingly rare, and the prognosis is poor.
An elderly female patient with a complex medical history, including peripheral artery disease and chronic wounds secondary to venous stasis, presented with worsening right lower extremity wounds despite outpatient antibiotic treatment (
Glioma-associated oncogene homologue 1 (GLI1) was recently shown to be coamplified with mouse double minute 2 (MDM2), cyclin-dependent kinase 4 (CDK4) and some other adjacent genes in a significant subset of GLI1-altered mesenchymal tumours and well-differentiated/dedifferentiated liposarcomas, which are characterised by MDM2 amplification. Given that MDM2 is also amplified in low-grade osteosarcoma (LGOS), we investigated the prevalence of GLI1 amplifications/fusions in a series of 15 cases of MDM2-amplified LGOS, an area that has not been previously explored.
This study conducted a retrospective analysis and examined GLI1 amplifications/fusions in 15 cases of MDM2-amplified LGOS and 46 cases of other bone tumours and tumour-like lesions using fluorescence in situ hybridisation with a GLI1 amplification probe and a GLI1 break-apart probe. Six cases of LGOS were also tested by next-generation sequencing.
Fluorescence in situ hybridisation analysis revealed that 13 of 15 (87%) LGOS cases exhibited GLI1 amplification; no fusion gene was found. Next-generation sequencing revealed that all six tested cases showed GLI1 amplification and one case had both GLI1 amplification and GLI1 gene fusion (PPM1H::GLI1). All 46 cases of other bone tumours and tumour-like lesions were negative for GLI1 amplification and GLI1 fusion.
These results indicate that GLI1 amplification is common in LGOS, and GLI1 fusion could occur in LGOS.
Gallbladder carcinoma (GBC) is frequently diagnosed and treated in advanced stages and has a poor prognosis. Recent studies have identified claudin18.2 (CLDN18.2) as a promising target in digestive system cancer. In this study, we aimed to determine the expression of CLDN18.2 and its correlation with clinicopathological characteristics in patients with GBC.
The expression of CLDN18.2 of 228 patients with GBC was studied via immunohistochemistry. Immunostained samples were evaluated according to the H-score. The samples were divided into low/negative (H-score=0–49) and high/positive (H-score=50–300) expression groups. The correlations between CLDN18.2 and various clinicopathological characteristics, including survival, were assessed. Multiplex immunofluorescence and image acquisition were used to analyse the relationship between CLDN18.2 expression and the immune microenvironment.
The overall positive CLDN18.2 staining rate was 39.91% (91/228); 137 (60.08%) were given 0 points, 30 (13.15%) were given 1 point, 28 (12.28%) were given 2 points and 33 (14.47%) were given 3 points. Low CLDN18.2 expression was correlated with adverse prognostic factors, including poor differentiation, deep infiltration depth, lymph node metastasis and distant metastasis. High CLDN18.2 expression was associated with better survival. Furthermore, the distribution of immune cell subsets significantly differed between the high and low CLDN18.2 expression groups.
The correlations between the expression of CLDN18.2 and clinicopathological characteristics and prognosis suggest that early-stage patients could benefit more from future anti-CLDN18.2 treatment and that CLDN18.2 may function as a pivotal regulatory molecule in patients with GBC. The underlying mechanism may be related to immune activation caused by high CLDN18.2 expression.
There are limited data on programmed death ligand 1 (PD-L1) expression in oesophageal cancer (OC) from multicentre studies conducted across China. We aimed to determine the prevalence of high PD-L1 expression in patients with advanced OC.
The EXCEED study was a multicentre, retrospective analysis of data from six tertiary hospitals that evaluated PD-L1 expression in adults with advanced OC or advanced head and neck squamous cell carcinoma. PD-L1 expression was evaluated at each site according to a standardised protocol. The primary outcome was the prevalence of high PD-L1 expression (Combined Positive Score (CPS) ≥10) in surgical or tumour biopsy samples. Low PD-L1 expression was defined as CPS <10. Patient demographic and baseline factors associated with high PD-L1 expression were also investigated. This report presents the results for the OC cohort only.
Overall, 482 patients were included, the majority were male (87.6%) and the mean age at diagnosis was 63.3 years; 207 had high PD-L1 expression (42.9%; 95% CI 38.5, 47.5) and 275 had low expression (57.1%; 95% CI 52.5, 61.5). There were significant differences in high PD-L1 expression prevalence between subgroups by sex (p=0.044), number of distant metastases (p=0.020), and if chemotherapy (p=0.004) was received prior to the collection of biological samples (ie, biopsy or surgery).
These real-world data provide a robust estimate of the prevalence of high PD-L1 expression in patients with advanced OC and identify clinicopathological and treatment features related to PD-L1 expression that can inform treatment selection.
Calcified chondroid mesenchymal neoplasm (CCMN) is a recently identified category of soft tissue neoplasms defined by cartilage or cartilaginous matrix formation and FN1 gene fusions. Its rarity and similarities to other soft tissue tumours pose diagnostic challenges. This study aims to deepen understanding of CCMN, highlighting molecular pathology’s role in diagnosis to reduce misdiagnosis, overdiagnosis and overtreatment.
We conducted a clinicopathological analysis of five newly identified CCMN cases and reviewed 87 cases documented in PubMed. Next-generation sequencing was used to detect molecular alterations, while clinical, radiological and histopathological features were extensively reviewed.
CCMN typically affects adults, presenting as a slow-growing, painless mass in soft tissue. Histologically, CCMN exhibits a chondroid matrix with variable calcification. Molecular analyses in our cases identified FN1::FGFR1, FN1::FGFR2 and FN1::TEK fusions. Review of the 87 cases revealed consistent clinical, imaging and molecular profiles, underscoring CCMN’s distinct characteristics.
CCMN should be considered in the differential diagnosis of soft tissue tumours with chondroid and calcified components. Detecting FN1 gene fusions aids in distinguishing CCMN from morphologically similar tumours.
To investigate the clinicopathological features and molecular characteristics of sporadic hypertrophic and nodular port-wine stains (PWS).
We analysed the clinicopathological and molecular characteristics of 27 sporadic hypertrophic and nodular PWS retrieved from our pathology database from 2013 to 2023 and reviewed the relevant literature.
There were 13 men and 14 women who ranged in age from 10 to 66 years. The main sites were the head and neck (23/27, 85%), which showed irregular thickening and darkening of purplish-red patches on the skin surface and the development of nodularity. Histologically, immature venule-like channels with irregular dilation are arranged in clusters or honeycombs, which are widely distributed primarily in the papillary layer and deep dermis and partly extend into the subcutaneous fat layer and other deep tissues. Dilated vessels with irregular shapes often exhibit fibrous thickening and an increased number of large vessels without vascular endothelial cell proliferation. All vessels showed similar characteristics, with positive staining for CD34, ERG and GNAQ in the endothelial cells, and negative staining for elastic fibres. Nine patients had somatic GNAQ mutations (9/11, 82%), including exon four mutations (6 cases, p.R183Q), exon five mutations (2 cases, p.Q209R) and exon two mutations (one case, p.G48V). Two patients had somatic BCL6 corepressor-like 1 (BCORL1) gene mutations (2/11, 18%), including exon 3 mutations (p.T1111M) and exon 7 mutations (p.G1391R).
Sporadic hypertrophic and nodular PWS are mostly related to somatic GNAQ mutations. This is the first study to identify the Rare GNAQ G48V and somatic BCORL1 mutations.
Fibrocartilaginous dysplasia (FCD) is a subvariant of fibrous dysplasia (FD). This study aims to retrospectively elucidate the clinicopathological and separate genetic features of the cartilaginous and fibro-osseous components of FCD.
In total, 24 patients (14 men and 10 women) with FCD were included in our cohort. The diagnosis was confirmed morphologically and immunohistochemically, and genetic features were determined via Sanger sequencing.
Five patients were polyostotic, and 19 were monostotic, predominantly concerning the femur. Radiography revealed a well-demarcated ground glass appearance with ring-like or scattered calcification. Histologically, the lesions were characterised by proliferative fibroblasts, immature woven bone and highly differentiated hyaline cartilage. The fibro-osseous components exhibited positive immunoreaction with SATB2 and a low Ki-67 proliferation index. The fibro-osseous and cartilaginous components shared mutations at codon 201 in exon 8 of the guanine nucleotide-binding protein/a-subunit (GNAS) gene, specifically CGT>CAT (p.R201H) in four patients and the wild-type isocitrate dehydrogenase (IDH)1/IDH2 gene. Telomerase reverse transcriptase (TERT) promoter mutations (C288T and C229G) occurred in both fibro-osseous and cartilaginous components in two patients.
FCD encompasses areas of conventional FD with additional cartilage. Importantly, the presence or absence of mutations in the GNAS gene and/or the TERT promoter is common between the fibro-osseous and cartilaginous components of the disease. These results further confirmed FCD as a variant of FD.
Mesenchymal neoplasms characterised by ALK fusions mainly include inflammatory myofibroblastic tumour (IMT) and epithelioid fibrous histiocytoma (EFH). Most recently, ALK-rearranged mesenchymal tumours that are not IMT or EFH have been reported. Our aim is to further characterise eight such neoplasms, with a detailed clinicopathological, immunohistochemical and molecular analysis.
Clinicopathological features were assessed and partner agnostic targeted RNA-sequencing on clinically validated platforms was performed.
The patients consisted of seven males and one female with a median age of 47 years (28 –59 years). The tumours ranged in size from 2.0 to 10.0 cm (mean=3.0 cm) and involved superficial and deep soft tissue (n=6) and visceral locations (n=2). Of the seven patients with follow-up (9–130 months), two developed distant metastases and five had no disease recurrence or metastasis. The tumours demonstrated diverse architectures and variable cellularity and cellular morphologies. The main constitutive cells appeared in elongated spindled in three, primitive to ovoid in two and round to epithelioid in three cases. We expanded the histopathological spectrum to include mildly to moderately cellular spindled to stellate cells in a multinodular growth in a prominent myxoid and vascularised stroma (n=2). All tumours expressed ALK(D5F3); seven were positive for S100 protein and six were positive for CD34. By fluorescence in situ hybridisation, ALK rearrangement was identified in all eight tumours. ALK fusion partners were identified by RNA-sequencing in all cases, including previously reported: EML4 (n=3), DCTN (n=1), CLIP1 (n=1) and PLEKHH2 (n=1), and also two novel fusion partners: TKT (n=1) and MMP2 (n=1).
Our study expands the clinicopathological and molecular spectrum of ALK-rearranged mesenchymal neoplasms.
In the time of COVID-19, predictive molecular pathology laboratories must still timely select oncological patients for targeted treatments. However, the need to respect social distancing measures may delay results generated by laboratory-developed tests based on sequential steps a long hands-on time. Laboratory workflows should now be simplified.
The organisation of the University of Naples Federico II predictive pathology laboratory was assessed before (March–April 2019) and during (March–April 2020) the Italian lockdown.
The number of patients undergoing single or multiple biomarker testing was similar in 2019 (n=43) and in 2020 (n=45). Considering adequate samples for molecular testing, before the outbreak, next-generation sequencing was mostly used (35/42, 83.3%). Testing six genes had a reagent cost of 98/patient. Conversely, in 2020, almost all cases (38/41, 92.7%) were analysed by automated testing. This latter had for any single assay/gene a significant reagent cost (95–136) and a faster mean turnaround time (5.3 vs 7.9 working days).
In the times of coronavirus, laboratory fully automated platforms simplify predictive molecular testing. Laboratory staff may be more safely and cost-effectively managed.