Background. Fusion involving NTRK1, NTRK2 and NTRK3 are oncogenic driver occurring in several adult and pediatric tumor types. In sarcomas they are mostly found in infantile fibrosarcoma, inflammatory (IFS), inflammatory myofibroblastic tumor (IMT) and in the so-called "NTRK-rearranged spindle cell neoplasm" entity described in the current WHO (2020) classification, including lipofibromatosis-like neural tumor, fibrosarcoma-like and malignant peripheral nerve sheath tumor-like spindle cell neoplasms. Methods. We retrospectively reviewed 92 soft tissue and bone sarcomas diagnosed at the Rizzoli Institute between 2019 and 2023, in which pan-TRK IHC was performed. 17 tumours showed positive staining and were further assessed using FISH for NTRK1, NTRK2, and NTRK3 rearrangements. A subset of 12 cases underwent RNA-based NGS for fusion detection. Results. In total, we collected data from 17 patients who tested positive for pan-TRK antibody and compared pan-TRK IHC and molecular testing for the detection of NTRK rearrangement in sarcomas. FISH analysis detected NTRK rearrangements in 4/17 cases (23.5%), while NGS confirmed NTRK fusions in 3/12 cases (25%). All NTRK fusion-positive cases confirmed by both FISH and NGS showed diffuse pan-TRK staining. Two additional cases exhibited pan-TRK diffuse positivity but were NTRK wild-type by NGS and harboured BCOR::MAML1 and EWSR1::NACC2 fusions, respectively. 1 case with focal positivity by immunohistochemistry and NTRK rearrangement by FISH was not confirmed by NGS. Conclusions. Pan-TRK IHC can be considered an initial screening tool to identify sarcomas potentially harbouring NTRK fusions. However, the presence of diffuse pan-TRK immunoreactivity in NTRK-wild-type tumours highlights the need for cautious interpretation of IHC results. FISH may represent a useful intermediate diagnostic tool when NGS is unavailable but requires cautious interpretation particularly in cases with atypical or isolated signals. NGS-based molecular confirmation remains essential for the definitive identification of NTRK fusions.
Background:Mutations in the isocitrate dehydrogenase (IDH) genes are key biomarkers in intrahepatic cholangiocarcinoma (CCA) and adult-type diffuse gliomas, although real-world adoption of comprehensive molecular diagnostics remains uneven. This review aimed to integrate published evidence, clinical experience, and international guidelines to provide pragmatic recommendations that can standardize IDH testing across healthcare systems. Methods:A multidisciplinary panel synthesized data identified through 10 PICO-driven questions, critically appraised guideline statements from ESMO, EANO, NCCN, and WHO-CNS5, and incorporated insights from clinical evidence on IDH molecular profiling in CCA patients. Recommendations were developed through interactive expert discussion. Results:The panel addressed six issues: (i) positioning of next-generation sequencing (NGS) as a first-line assay; (ii) using liquid biopsy to supplement inadequate or uninformative tissue-based molecular analyses; (iii) tumor-adapted workflows combining immunohistochemistry, PCR, or NGS with large genomic panels; (iv) optimizing pre-analytical management of small biopsies in terms of neoplastic cell abundance and nucleic acid fragmentation to safeguard material for integrated testing; (v) evaluating promising biomarkers based on genome-wide methylation profiling and metabolic imaging in specialized centers; and (vi) novel testing strategies including centralized and decentralized algorithms. In addition, emerging approaches based on digital pathology, teleconsultation, and harmonized reimbursement pathways were discussed. These considerations were distilled into a set of "Golden Rules." Conclusions:Optimized molecular profiling is a cornerstone of precision oncology in IDH-mutant tumors, but the lack of harmonized procedures hinders its widespread implementation in the clinical setting. In intrahepatic CCA, upfront NGS should be prioritized to capture the full spectrum of actionable alterations, whereas in diffuse gliomas IHC for IDH1 p.R132H remains recommended, with PCR or NGS reserved for IHC-negative or equivocal cases. Advanced tools such as genome-wide methylation profiling or metabolic imaging may add value in specialized centers. The consensus-based "Golden Rules" pragmatically support harmonization of diagnostic workflows, reducing technical costs and turnaround time, and promoting equitable access to IDH-directed therapies across diverse healthcare settings.
Tumor-to-tumor metastasis (TTM) refers to a malignant tumor metastasizing to a second, distict tumor. It is a rare phenomenon and the most common donor organs are the lung and breast. Here in, we report a case of TTM metastasis of breast carcinoma metastasizing to an adrenocortical adenoma (ACA) in a 40-year-old woman. To the best of our knowledge, this is the first case in which TTM of breast carcinoma metastasizes to an ACA.
A 60-year-old woman with end-stage fibrosing interstitial lung disease (ILD) underwent bilateral lung transplantation. Systematic histological analysis of the explanted lungs revealed extensive lymphangitic carcinomatosis and hilar lymph node metastases from a previously undiagnosed breast carcinoma. Retrospective imaging review identified a suspicious mammographic finding that had not been further investigated. The patient was later diagnosed with metastatic breast cancer and passed away at 12 months post-transplant. This case emphasizes the challenging diagnosis of neoplasia in end-stage lung disease. The incidence of malignancies in explanted lungs is approximately 1.65%, with metastatic cases being extremely rare. This report underscores the importance of thorough histopathological evaluation of explant lungs, advocating for standardized examination protocols to improve the accuracy and depth of pathological diagnosis.
Pathology education is evolving beyond traditional textbooks and increasingly embracing digital and active learning tools. While passive methods of teaching such as lectures remain dominant, active learning approaches-such as case-based learning, gamification, and technology-enhanced education-are on the rise. Tools like digital microscopy, social media, and resources such as Libre Pathology and pathCast are democratizing access to knowledge, fostering interactivity and accessibility. Quizzes and gaming events have become essential tools in medicine, enhancing learner engagement, honing diagnostic skills, and promoting collaborative learning. Notable examples in pathology include the ESP Pathology Progress Test, the RCPath International Pathology Day Quiz, and interactive events like the ISDP Dermatopathology Olympic Games. Gamification not only boosts motivation but also facilitates the practical application of real-world skills. These innovations are particularly impactful in pathology, where simulated diagnostic challenges offer realistic learning experiences. The inaugural SIAPeC Quiz (2024) demonstrated the efficacy of gamification in pathology education, combining interactive case-based challenges with digital tools to enhance diagnostic skills and engagement among junior pathologists. Featuring a diverse range of questions across histology, pathology, and subspecialties, the event incorporated whole-slide images and challenges that push the boundaries of what can be understood from minimal information (#TooCloseToDiagnose and #TooFarToDiagnose). This gamified format created a supportive environment for learners to experiment and learn from mistakes, fostering critical skills in a dynamic setting.
Achieving complete tumor removal with negative margins remains a major goal in oncologic surgery. Frozen section analysis is still the most widely used method for intraoperative margin assessment, but it has several limitations, including time consumption, costs, and the need for dedicated pathology support. In this context, Histolog® Scanner has emerged as a fluorescence confocal microscopy device that enables rapid digital evaluation of freshly excised tissue without conventional histological processing. This systematic review aimed to evaluate the current clinical applications of Histolog® Scanner, its diagnostic performance, and its concordance with conventional histopathological assessment. Most included studies focused on breast surgery, followed by dermatologic, prostatic, and head and neck applications. Reported sensitivity ranged from 30% to 100%, specificity from 75% to 100%, and overall diagnostic accuracy reached up to 99% in selected settings. Current evidence supports the feasibility and promising diagnostic performance of Histolog® Scanner in selected oncologic fields. However, the available literature remains limited and heterogeneous and is still insufficient to support replacement of frozen section analysis in routine practice. Further large-scale prospective studies are needed to better define its reproducibility, cost-effectiveness, and potential role across different oncologic settings, particularly in head and neck surgery.
We report two singular cases of sudden death in which the cause was advanced tuberculosis infection. In the first case, a 24-year-old man died suddenly following massive hemoptysis due to erosion of the pulmonary vessels. The second case involved a 29-year-old man who died unexpectedly from asphyxia secondary to hemoptysis caused by fibrocavitatory tuberculosis. Toxicological screening and HIV testing were negative in both cases. Medico-legal autopsy, combined with detailed histological examination, was essential to determine the exact cause of death.
Medical museums are increasingly challenged to balance accessibility, educational effectiveness, and ethical responsibility, particularly when displaying human remains. Despite growing interest in digital museology, limited attention has been paid to its application in contexts involving culturally sensitive materials. This study presents a qualitative case study of the renovation of the Morgagni Museum of Human Anatomy (University of Padua), focusing on the integration of digital tools, including quick response codes, augmented reality (AR), and virtual itineraries. The project aimed to enhance accessibility and public engagement while preserving the scientific and ethical integrity of the collection. The results, based on observational data collected during guided visits and educational activities, indicate that hybrid interpretive strategies combining digital and traditional tools improve visitor engagement, support layered learning, and foster a more informed interaction with anatomical and pathological specimens. In particular, the use of AR and digital content was associated with increased student participation and enhanced observational skills. This case study demonstrates that digital technologies, when embedded within a coherent curatorial framework, can strengthen rather than diminish ethical engagement with human remains. The Morgagni Museum provides a model for the sustainable and responsible reinterpretation of historical medical collections in contemporary educational contexts.
Objective:To assess the frequency, morphological features, and perinatal/forensic relevance of nodular fibromuscular villous stromal dysplasia (NFMVSD) in a large retrospective placental series. Methods:Placentas examined between 2014-2018 were retrospectively reviewed. Cases fulfilling diagnostic criteria for NFMVSD were re-evaluated macro- and microscopically, with smooth muscle actin and desmin immunostains when required. Placental weight centiles, lesion distribution, associated abnormalities, and pregnancy outcomes were recorded. Results:NFMVSD was identified in 27 placentas (1.34%), mainly involving second-/third-order villi with multifocal nodular growth. Sixty-three percent were below the 25th weight percentile. Common findings included hypoxic distress (55%), stem vessel sclerosis (39%), and villous immaturity or dysmaturity (42%). Two intrauterine deaths (6%), four neonatal deaths (14%), and congenital anomalies (32%) occurred. Conclusions:NFMVSD represents a distinct placental lesion with medicolegal significance, often associated with low placental weight, vascular changes, and hypoxic features. Its recognition may help clarify unexplained fetal or neonatal deaths. Standardized criteria and multicenter studies are required to refine its clinical and forensic implications.
Objective. Cervical cancer remains a major global health burden, where early detection is critical. Cytological and histological assessments aim to identify precancerous squamous intraepithelial lesions (SILs). While artificial intelligence and machine learning have shown promise, most approaches rely on cytology or are not tailored for SIL classification. The aim of this study is to develop and evaluate a weakly supervised, pixel-level machine learning framework for the histological classification of low grade and high grade SIL in whole slide images (WSIs). Specifically, we sought to assess whether an open source segmentation pipeline trained on sparsely annotated WSIs could accurately support slide-level diagnostic interpretation while minimizing annotation burden and maintaining clinical interpretability. Methods. We propose a weakly supervised machine learning framework for classifying low grade and high grade SILs in whole-slide histological images. Using Random Forest classifiers for pixel-level segmentation, the system mimics pathologists by quantifying tissue components. Training required only sparse annotations from a limited set of WSIs, yielding millions of pixel-level samples and reducing annotation burden. Results. Applied on a test set of 309 cervical WSIs, the system achieved over 96% concordance with expert pathologists, correctly distinguishing low grade LSIL, high grade HSIL, and normal epithelium, with only one false negative and a 7-10 false positives, depending on the used model. Conclusions. Our approach offers accurate, interpretable, and low-cost diagnostic support, with potential for integration into routine workflows, especially in resource-limited settings.
Background:Next generation sequencing (NGS) impacted on clinical algorithm of solid tumor patients. A heterogeneous series of NGS platforms have been implemented in clinical practice but challenging handling procedures, high technical costs, and scant affordability on sequencing diagnostic routine specimens can leave behind some patients who could benefit from target drugs. Here, we sought to evaluate technical feasibility of Oxford Nanopore Technologies (ONT) sequencing accurate identification of tumor-associated molecular alterations, in a pilot series of real-world samples. Methods:We developed a technical workflow adapting the SiRe® NGS panel, originally designed for Ion semiconductor sequencing, on MinION platform (Oxford nanopore technologies), a portable, cost effective long read sequencer. The SiRe® panel enables detection of ٥٦٨ clinically actionable somatic mutations across six key genes (EGFR, KRAS, NRAS, BRAF, cKIT, PDGFRα) relevant to targeted therapies in several solid tumors. We implemented a multiplexed assay using pooled and barcoded samples, processed on a single MinION flow cell. Performance was benchmarked from a pilot series of nine FFPE samples against Ion Torrent sequencing data. A single liquid biopsy sample was also analyzed testing accuracy of MinION technology. Results:The adapted ONT workflow demonstrated high concordance ratei in detecting clinically relevant molecular alterations on short-read fragments, achieving comparable accuracy with standardized second generation NGS platforms on tissue and liquid biopsy samples. Conclusions:This proof of concept aimed to integrate ONT sequencing into molecular oncology workflows, providing practical, low-cost, and scalable alternative to conventional NGS platforms. The results support the potential of ONT technology to democratize access to precision oncology, particularly in laboratories with limited resources.
We report a BRAF V600E-mutated cutaneous melanoma (pT3b) with nodal metastases treated with neoadjuvant anti-PD-1 therapy. Axillary lymph node dissection demonstrated residual viable melanoma intimately associated with extensive heterologous lamellar bone formation within the post-treatment tumor bed. Histologic assessment supported a melanoma-related heterologous component rather than a purely reactive stromal phenomenon, underscoring a relevant diagnostic pitfall in treated specimens. The observation also has practical implications for pathological response evaluation after neoadjuvant immunotherapy: in this case, the osseous component was integrated into the viable tumor compartment to avoid underestimation of residual disease. Overall, this case exemplifies the evolving morphobiological spectrum of melanoma in the immunotherapy era, and emphasizes that careful correlation of morphology with the clinical context remains the mainstay to avoid misinterpretation, particularly when uncommon heterologous or metaplastic patterns emerge after immune checkpoint blockade.
Palisading adenocarcinoma is a newly described salivary gland tumor known for its predilection for sublingual and submandibular glands. The mass tends to have a non-invasive growth, although signs of infiltrative growth can occur resulting in a neoformation more adherent to deep neck structures. The main histological feature is a biphasic cellular pattern composed of polygonal epithelioid cells with small nuclei arranged in trabeculae and pseudo-rosette like structures and a second population of scattered well-formed ductal structures with occasional mucocytes. The mass, located in the parotid gland, resembled a neuroendocrine neoplasia regarding its histological architecture and positivity for CD56, whereas the cytological examination resembled that of a pleomorphic adenoma. An accurate histological and immunohistochemical study was crucial to guide the differential diagnosis. Here we present the first case of palisading adenocarcinoma affecting the parotid gland to further enrich the literature and to shed additional light on this peculiar and recently investigated neoplastic entity.
This letter reports a case of a gestational pemphigoid (GP), a rare autoimmune subepidermal blistering disorder, typically arising in the third trimester of pregnancy. Early-onset presentations, during the first trimester, are exceptionally uncommon and may mimic other pregnancy-related dermatoses, delaying diagnosis. We report a rare early-onset case of GP and discuss the diagnostic challenges and management implications, allowing timely diagnosis and treatment, reducing maternal morbidity and potential obstetric complications.
This study re-examines a rare neuropathological case documented by Ettore Ravenna in 1900, involving a young patient with chorea, epilepsy, and marked frontal lobe atrophy. Using Ravenna's original autopsy notes and the preserved anatomical preparation at the Morgagni Museum of Human Anatomy (Padua), the case is reassessed in light of modern neurological knowledge. Macroscopic examination confirmed severe anterior frontal atrophy with relative preservation of peri-Sylvian regions, consistent with the patient's ability to sing despite profound language impairment. Ravenna described gliosis, fibrotic tissue replacement, and neuronal hyaline degeneration, interpreted as ulegyria of inflammatory origin. Although he considered epilepsy and chorea expressions of a single pathology, current research differentiates their mechanisms. However, juvenile neurodegenerative disorders such as Huntington disease show overlapping seizures, chorea, and cortical atrophy, partially supporting his observations. Re-evaluating this case highlights its historical relevance and the value of anatomical collections in reassessing early diagnoses.
Objective. To develop and validate a deep learning model trained on reticulin-stained whole slide images (MesoRet) to accurately identify transitional features and assist in the histologic subtyping of diffuse mesothelioma. Methods. A total of 115 cases of diffuse mesothelioma were collected from two institutions and reviewed by expert thoracic pathologists. Reticulin-stained whole-slide images were used to train a supervised deep learning model on the Aiforia Create platform to distinguish epithelioid, sarcomatoid, and transitional patterns. Model performance was validated on independent slides and compared with expert pathologists' assessments. Results. MesoRet accurately identified reticulin patterns across mesothelioma histotypes achieving 96.32% precision and 99.06% sensitivity, excluding artifacts and non-tumour tissue. It outperformed pathologists in identifying transitional patterns, reducing diagnostic time and minimising errors. Conclusions. MesoRet provides an accurate and objective approach for detecting reticulin patterns in mesothelioma, supporting histological subtyping and contributing to more consistent diagnoses. Although further validation is required, it represents a promising model to improve diagnostic precision and guide therapeutic decision-making.
Objective. Automated paraffin embedding (AE) offers a solution to the operator-dependent variability and time demands manual embedding (ME), but comparative data are limited. Methods. We quantitatively assessed AE versus ME using 186 endoscopic biopsies, 106 needle biopsies, and 62 transurethral resections, recording the time (seconds, s) required for preparation, embedding, trimming, and sectioning. Results. AE substantially reduced embedding time (5 s for all sample types) compared with ME (43 s for endoscopic biopsies, 66.5 s for needle biopsies, and 105 s for transurethral samples), and it allowed laboratory technicians to perform other tasks concurrently. AE also shortened total time: 150.2 s (AE) vs. 250.4 s (ME) for endoscopic biopsies, 176.9 s (AE) vs. 324.2 s (ME) for needle biopsies, and 149.5 s (AE) vs. 335 s (ME) for transurethral resections. Conclusions. These real-world data provide quantitative evidence of AE-related time savings in daily routine activity, supporting its role in workflow automation and standardization in pathology units.
Over the past decade, significant progress has been made in understanding eosinophilic oesophagitis (EoE), leading to the refinement of diagnostic criteria and the development of evidence-based management guidelines. Nevertheless, despite the central role of histology in both diagnosis and disease monitoring, significant variability remains in histopathological reporting across institutions and among pathologists. This study seeks to provide recommendations for standardised histological reporting in EoE. To this end, a multidisciplinary panel of gastroenterologists and pathologists convened to review current practices and address persistent challenges in histologic assessment. Through an extensive literature review and critical appraisal of existing scoring systems, the panel reached consensus on both essential and desirable histological features for routine reporting, including eosinophil counts, additional inflammatory parameters, and fibrostenotic changes.
