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Pediatric germ cell tumors represent a rare but biologically diverse group of neoplasms arising from pluripotent primordial germ cells. The 2022 edition of the WHO Classification of Pediatric Tumors introduced the first organ independent classification of germ cell tumors, reflecting advances in molecular biology, histopathology, and clinical practice. This review highlights the key changes, including the refined distinctions between the different subtypes. These updates enhance diagnostic accuracy and provide a framework for understanding age-dependent differences in tumor biology and behavior. Emphasis is placed on integrating the new classification into multidisciplinary care, particularly in addressing diagnostic challenges in pre- and post-pubertal-type germ cell tumors. By bridging the gap between histopathology and oncology, the updated classification represents a pivotal step forward in improving outcomes for children with germ cell tumors., Competing Interests: Declarations. Conflict of interest: The authors declare no competing interests., (© 2025. The Author(s).)

Background: Sudden unexplained death (SUD) is a devastating event in the young. Despite efforts to identify causal genetic variants, many cases remain unexplained after genetic screening. This study aimed to investigate an alternative potential contributor to SUD by studying the human methylome using the MethylationEPIC v2.0 BeadChip kit in heart tissue from SUD cases. The genome-wide methylation results of the SUD cases were compared to the results of a control cohort. The SUD cases were divided into three main groups based on their autopsy reports, heart morphology and histopathology (primaryN: macroscopically and histologically normal heart; primaryCM: macroscopically or histologically abnormal heart, suspected cardiomyopathies; and secondary: myocardial damage due to other underlying conditions). The main focus of this study was to identify differentially methylated regions (DMRs) between the case groups and the control cohort., Results: We identified DMRs for both the primaryN and primaryCM groups, whereas the secondary group yielded no such results. In the primaryN cases, the corresponding genes for each DMR led to the identification of genes with common biological pathways. Some were associated with heart morphology (e.g. heart outflow tract morphogenesis or trabecular morphogenesis), but the majority belonged to more general cellular regulatory pathways (e.g. transcription coactivator activity, long non-coding RNAs, etc.). Although no common pathways were found for the primaryCM group, some common regulatory molecular functions were identified, such as p53 binding and transcription coactivator activity., Conclusions: Our study is the first to investigate the whole human methylome in heart tissue of SUD cases. We propose that there are observable differences in the methylation patterns of the case groups that may have contributed to SUD. Still, further studies are required to improve our understanding of the impact of methylation levels on SUD risk and to pinpoint methylation-based screening opportunities for SUD relatives., Competing Interests: Declarations. Ethics approval and consent to participate: Ethical approval for this study was provided by the local ethics committee in Zurich (KEK-No. 2013-0086), and the study was conducted in full conformance with Swiss laws and regulations. The requirements of the local ethics committee included written informed consent of family members. If no family members were available, the cases were anonymized. Consent for publication: All authors of the manuscript have read and agreed to its content and consent to publish it. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Personalized treatment for patients with advanced solid tumors critically depends on the deep characterization of tumor cells from patient biopsies. Here, we comprehensively characterize a pan-cancer cohort of 150 malignant serous effusion (MSE) samples at the cellular, molecular, and functional level. We find that MSE-derived cancer cells retain the genomic and transcriptomic profiles of their corresponding primary tumors, validating their use as a patient-relevant model system for solid tumor biology. Integrative analyses reveal that baseline gene expression patterns relate to global ex vivo drug sensitivity, while high-throughput drug-induced transcriptional changes in MSE samples are indicative of drug mode of action and acquired treatment resistance. A case study exemplifies the added value of multi-modal MSE profiling for patients who lack genetically stratified treatment options. In summary, our study provides a functional multi-omics view on a pan-cancer solid tumor cohort and underlines the feasibility and utility of MSE-based precision oncology., (© 2024. The Author(s).)

Rhabdomyosarcoma (RMS) is a highly aggressive pediatric cancer with features of skeletal muscle differentiation. More than 80% of the high-risk patients ultimately fail to respond to chemotherapy treatment, leading to limited therapeutic options and dismal prognostic rates. The lack of response and subsequent tumor recurrence is driven in part by stem cell-like cells, the tumor subpopulation that is enriched after treatment, and characterized by expression of the AXL receptor tyrosine kinase (AXL). AXL mediates survival, migration, and therapy resistance in several cancer types; however, its function in RMS remains unclear. In this study, we investigated the role of AXL in RMS tumorigenesis, migration, and chemotherapy response, and whether targeting of AXL with small-molecule inhibitors could potentiate the efficacy of chemotherapy. We show that AXL is expressed in a heterogeneous manner in patient-derived xenografts (PDX), primary cultures and cell line models of RMS, consistent with its stem cell-state selectivity. By generating a CRISPR/Cas9 AXL knock-out and overexpressing models, we show that AXL contributes to the migratory phenotype of RMS, but not to chemotherapy resistance. Instead, pharmacologic blockade with the AXL inhibitors bemcentinib (BGB324), cabozantinib and NPS-1034 rapidly killed RMS cells in an AXL-independent manner and augmented the efficacy of the chemotherapeutics vincristine and cyclophosphamide. In vivo administration of the combination of bemcentinib and vincristine exerted strong antitumoral activity in a rapidly progressing PDX mouse model, significantly reducing tumor burden compared with single-agent treatment. Collectively, our data identify bemcentinib as a promising drug to improve chemotherapy efficacy in patients with RMS., (©2024 The Authors; Published by the American Association for Cancer Research.)

Lymph node status is one of the most important prognostic factors in colorectal cancer, and accurate pathological nodal staging and detection of lymph node metastases is crucial for determination of post-operative management. Current guidelines, including the TNM staging system and European Society for Medical Oncology (ESMO) guidelines, recommend examination of at least 12 lymph nodes. However, identification of an adequate number of lymph nodes can be challenging, especially in the setting of neoadjuvant treatment, which may reduce nodal size. In this study, we investigated 384 colorectal cancer resections that were processed at our department of pathology between January 2012 and December 2022, in which the number of detected lymph nodes was less than 12 subsequent to conventional preparation of mesocolic fat tissue. By means of acetone compression, lymph node harvest increased significantly (p < 0.0001), and the intended number of ≥ 12 lymph nodes was achieved in 98% of resection specimens. The number of nodal positive cases increased significantly from n = 95 (24.7%) before versus n = 131 (34.1%) after acetone compression due to additionally identified lymph node metastases (p < 0.001). In 36 patients (9.4%) initially considered as nodal negative, acetone compression led to a staging adjustment to a nodal positive category and thereby drove a recommendation to offer post-operative therapy. In conclusion, acetone compression is a reliable and useful method implementable in routine surgical pathology for the retrieval of lymph nodes in colorectal cancer specimen, allowing for an adequate lymph node sampling and an increase in nodal staging reliability., (© 2023. The Author(s).)

Aims We aimed to assess the performance of bladder wash cytology (BWC) in daily clinical practice in a pure follow-up cohort of patients previously diagnosed with non-muscle invasive bladder cancer (NMIBC). Materials and methods We analyzed 2064 BWCs derived from 314 patients followed for NMIBC (2003-2016). Follow-up investigations were performed using cystoscopy (CS) in combination with BWC. Patients with suspicious CS and/or positive BWC underwent bladder biopsy or transurethral resection. BWC was considered positive if malignant or suspicious cells were reported. Sensitivity (Sn) and specificity (Sp) were calculated for the entire cohort and separately for low-grade (LG) and high-grade (HG) tumors, and carcinoma in situ (CIS) subgroups. Results A total of 95 recurrences were detected, of which only three were detected by BWC alone. Overall, Sn and Sp of BWC were 17.9% and 99.5%, respectively. For LG disease, these numbers were 14.0% and 100%, and for HG disease, these were 22.2% and 99.1%, respectively. For patients with CIS at initial diagnosis, Sn and Sp were 11.0% and 71.4%, respectively. For isolated primary CIS, Sn was 50.0%, and Sp was 98.2%. Conclusion Routine use of BWC in the follow-up for NMIBC is of limited value even in HG tumors. In the presence of isolated primary CIS, adjunct BWC might be justified., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2023, Bieri et al.)

Background: Fine-needle aspiration cytology (FNAC) represents an important diagnostic tool for the workup of salivary gland (SG) lesions. The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) is a six-tiered system for standardizing diagnoses and improvement of communication between pathologists and clinicians, providing risk of malignancy (ROM) rates for every category. The aims of the present study were (i) to validate the use of MSRSGC in a large series of SG FNAC in a tertiary center in Switzerland, (ii) to determine ROM for each category and compare them with data from MSRSGC and similar studies, and (iii) to investigate whether there were relevant differences of non-diagnostic results between fine-needle aspirations (FNA) performed by cytopathologists compared to non-cytopathologists., Methods: The files of the department of Pathology in the University Hospital Zurich (UHZ) were searched for SG FNAC between 2010 and 2019. The MSRSGC guidelines were applied retrospectively. Furthermore, ROM, risk of neoplasia (RON), sensitivity, and specificity were calculated based on the cases with histopathological follow-up., Results: A total of 2156 SG FNAC including 753 cases with histopathological follow-up were evaluated. Generally, ROM was within the range of values provided by MSRSGC, with some minor deviations. Sensitivity was 94.6%, and specificity was 99.3%., Conclusions: Our study confirms the usefulness of MSRSGC. In addition, it provides a detailed insight into the wide spectrum of SG FNAC. Finally, we showed that the rate of non-diagnostic FNA was significantly lower in FNAs performed by cytopathologists compared to non-cytopathologists., (© 2023 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

Personalized treatment of metastatic non-squamous non-small cell lung cancer (NSCLC) requires detailed molecular characterization of the tumour including detection of predictive driver mutations and programmed death ligand 1 (PD-L1) expression. Complete detection is influenced by the amount of tumour cells sampled as well as their quality. Different sampling techniques may be necessary to provide sufficient tumour material for comprehensive molecular characterization. Missing the detection of targetable molecular genetic aberrations would have a serious impact on the quality of life and prognosis of a patient. This case report highlights the importance of biopsy technique in a patient with NSCLC. Several procedures-pleural puncture, transthoracic lung biopsy and endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA)-could not provide sufficient tumour material for precise tumour characterization. Only the addition of EBUS-guided transbronchial lymph node cryobiopsy (EBUS-TBLNC) enabled complete immunohistochemical and genetic tumour characterization, demonstrating PD-L1 expression in 100% of the tumour cells in the absence of actionable genetic alterations. Based on these results, immunotherapy was initiated.

Rhabdomyosarcoma (RMS) is a group of pediatric cancers with features of developing skeletal muscle. The cellular hierarchy and mechanisms leading to developmental arrest remain elusive. Here, we combined single-cell RNA sequencing, mass cytometry, and high-content imaging to resolve intratumoral heterogeneity of patient-derived primary RMS cultures. We show that the aggressive alveolar RMS (aRMS) subtype contains plastic muscle stem-like cells and cycling progenitors that drive tumor growth, and a subpopulation of differentiated cells that lost its proliferative potential and correlates with better outcomes. While chemotherapy eliminates cycling progenitors, it enriches aRMS for muscle stem-like cells. We screened for drugs hijacking aRMS toward clinically favorable subpopulations and identified a combination of RAF and MEK inhibitors that potently induces myogenic differentiation and inhibits tumor growth. Overall, our work provides insights into the developmental states underlying aRMS aggressiveness, chemoresistance, and progression and identifies the RAS pathway as a promising therapeutic target.

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children. The prognosis for patients with high-grade and metastatic disease is still very poor, and survivors are burdened with long-lasting side effects. Therefore, more effective and less toxic therapies are needed. Surface proteins are ideal targets for antibody-based therapies, like bispecific antibodies, antibody-drug conjugates, or chimeric antigen receptor (CAR) T-cells. Specific surface targets for RMS are scarce. Here, we performed a surfaceome profiling based on differential centrifugation enrichment of surface/membrane proteins and detection by LC-MS on six fusion-positive (FP) RMS cell lines, five fusion-negative (FN) RMS cell lines, and three RMS patient-derived xenografts (PDXs). A total of 699 proteins were detected in the three RMS groups. Ranking based on expression levels and comparison to expression in normal MRC-5 fibroblasts and myoblasts, followed by statistical analysis, highlighted known RMS targets such as FGFR4, NCAM1, and CD276/B7-H3, and revealed AGRL2, JAM3, MEGF10, GPC4, CADM2, as potential targets for immunotherapies of RMS. L1CAM expression was investigated in RMS tissues, and strong L1CAM expression was observed in more than 80% of alveolar RMS tumors, making it a practicable target for antibody-based therapies of alveolar RMS.

Purpose: Rhabdomyosarcoma (RMS) is an aggressive soft-tissue sarcoma, which primarily occurs in children and young adults. We previously reported specific genomic alterations in RMS, which strongly correlated with survival; however, predicting these mutations or high-risk disease at diagnosis remains a significant challenge. In this study, we utilized convolutional neural networks (CNN) to learn histologic features associated with driver mutations and outcome using hematoxylin and eosin (H&E) images of RMS., Experimental Design: Digital whole slide H&E images were collected from clinically annotated diagnostic tumor samples from 321 patients with RMS enrolled in Children's Oncology Group (COG) trials (1998-2017). Patches were extracted and fed into deep learning CNNs to learn features associated with mutations and relative event-free survival risk. The performance of the trained models was evaluated against independent test sample data (n = 136) or holdout test data., Results: The trained CNN could accurately classify alveolar RMS, a high-risk subtype associated with PAX3/7-FOXO1 fusion genes, with an ROC of 0.85 on an independent test dataset. CNN models trained on mutationally-annotated samples identified tumors with RAS pathway with a ROC of 0.67, and high-risk mutations in MYOD1 or TP53 with a ROC of 0.97 and 0.63, respectively. Remarkably, CNN models were superior in predicting event-free and overall survival compared with current molecular-clinical risk stratification., Conclusions: This study demonstrates that high-risk features, including those associated with certain mutations, can be readily identified at diagnosis using deep learning. CNNs are a powerful tool for diagnostic and prognostic prediction of rhabdomyosarcoma, which will be tested in prospective COG clinical trials., (©2022 The Authors; Published by the American Association for Cancer Research.)

Introduction: In most cases, the diagnostic workup of pleural mesotheliomas (MPMs) starts with cytological examination of pleural effusion, but histology is needed to confirm the diagnosis. The introduction of BAP1 and methylthio-adenosine phosphorylase (MTAP) immunohistochemistry has become a powerful tool to confirm the malignant nature of mesothelial proliferations also in cytological specimens. The objective of this study was to determine the concordance of BAP1, MTAP, and p16 expression between cytological and histological samples of patients with MPM., Methods: Immunohistochemistry of BAP1, MTAP, and p16 was performed on cytological samples and compared with the corresponding histological specimen of 25 patients with MPM. Inflammatory and stromal cells served as positive internal control for all three markers. In addition, samples of 11 patients with reactive mesothelial proliferations served as an external control group., Results: Loss of BAP1, MTAP, and p16 expression was found in 68%, 72%, and 92% of MPM, respectively. Loss of MTAP was associated with loss of p16 expression in all cases. Concordance of BAP1 between cytological and corresponding histological samples was 100% (kappa coefficient 1; p = 0.008). For MTAP and p16, kappa coefficient was 0.9 (p = 0.01) and 0.8 (p = 0.7788), respectively., Conclusions: Concordant BAP1, MTAP, and p16 expression is found between cytological and corresponding histological samples, indicating that a reliable diagnosis of MPM can be made on cytology only. Of the three markers, BAP1 and MTAP are most reliable in distinguishing malignant from reactive mesothelial proliferations., (© 2023 The Author(s). Published by S. Karger AG, Basel.)

Background: Somatic mosaicism for PIK3CA mutations causes various types of growth disorders, which have been summarized under the term PROS ( PIK3CA related overgrowth spectrum). Targeted therapy with PI3K inhibitors seems to be a promising alternative for severe PROS cases. Therefore, PIK3CA testing may become more relevant in the future., Methods: We report on 14 PROS patients, who had surgery for macrodactyly in the majority of cases. Clinical data were retrieved from the patient's records. Macroscopic and microscopic findings were retrospectively reviewed. Mutational analysis was performed on formalin-fixed paraffin-embedded (FFPE) material., Results: Patient age ranged from 7 months to 35 years. Five patients showed additional anomalies. One patient had CLOVES syndrome. The majority of the specimens were ray resections characterized by hypertrophic fat tissue. Overall, microscopy was subtle. The abnormal adipose tissue showed lobules exhibiting at least focally fibrous septa. In each case, we could detect a PIK3CA mutation., Conclusion: Histology of affected fat tissue in PROS patients is overall nonspecific. Therefore, mutational analysis represents the key to the diagnosis, especially in unclear clinical cases. We demonstrated that FFPE material is suitable for PIK3CA testing, which can be considered as basis for targeted therapy with PI3K inhibitors.

When evaluating mediastinal/hilar lymphadenopathy (LAD) or masses, guidelines recommend endobronchial ultrasound (EBUS)-guided transbronchial needle aspiration (TBNA) as an initial technique for tissue analysis and diagnosis. However, owing to the small sample size obtained by needle aspiration, its diagnostic yield (DY) is limited. EBUS transbronchial forceps biopsy (TBFB) used as a complimentary technique to EBUS-TBNA might allow for better histopathological evaluation, thus improving DY. In this retrospective bicentric study, we assessed the DY and safety of an EBUS-guided 1.5 mm mini-forceps biopsy combined with EBUS-TBNA for the diagnosis of mediastinal/hilar LAD or masses compared to EBUS-TBNA alone. In total, 105 patients were enrolled. The overall DY was 61.9% and 85.7% for TBNA alone and EBUS-TBNA combined with EBUS-TBFB, respectively (p < 0.001). While the combined approach was associated with a significantly higher DY for lung cancer diagnosis (97.1% vs. 76.5%, p = 0.016) and sarcoidosis (85.2% vs. 44.4%, p = 0.001), no significant differences in DY were calculated for subgroups with smaller sample sizes such as lymphoma. No major adverse events were observed. Using a 1.5 mm mini-forceps is a safe and feasible technique for biopsy of mediastinal or hilar LAD or masses with superior overall DY compared to EBUS-TBNA as a standalone technique., Competing Interests: The authors declare no conflict of interest.

Background: Post-mortem imaging has been suggested as an alternative to conventional autopsy in the prenatal and postnatal periods. Noninvasive autopsies do not provide tissue for histological examination, which may limit their clinical value, especially when infection-related morbidity and mortality are suspected., Methods: We performed a prospective, multicentre, cross-sectional study to compare the diagnostic performance of post-mortem magnetic resonance imaging with computed tomography-guided biopsy (Virtopsy®) with that of conventional autopsy in foetuses and infants. Cases referred for conventional autopsy were eligible for enrolment. After post-mortem imaging using a computed tomography scanner and a magnetic resonance imaging unit, computed tomography-guided tissue sampling was performed. Virtopsy results were compared with conventional autopsy in determining the likely final cause of death and major pathologies. The primary outcome was the proportion of cases for which the same cause of death was determined by both methods. Secondary outcomes included the proportion of false positive and false negative major pathological lesions detected by virtopsy and the proportion of computed tomography-guided biopsies that were adequate for histological examination., Results: Overall, 101 cases (84 fetuses, 17 infants) were included. Virtopsy and autopsy identified the same cause of death in 91 cases (90.1%, 95% CI 82.7 to 94.5). The sensitivity and specificity of virtopsy for determining the cause of death were 96.6% (95% CI 90.6 to 98.8) and 41.7% (95% CI 19.3 to 68.0), respectively. In 32 cases (31.7%, 95% CI 23.4 to 41.3), major pathological findings remained undetected by virtopsy, and in 45 cases (44.6%, 95% CI 35.2 to 54.3), abnormalities were diagnosed by virtopsy but not confirmed by autopsy. Computed tomography-guided tissue sampling was adequate for pathological comments in 506 of 956 biopsies (52.7%) and added important diagnostic value in five of 30 cases (16.1%) with an unclear cause of death before autopsy compared with postmortem imaging alone. In 19 of 20 infective deaths (95%), biopsies revealed infection-related tissue changes. Infection was confirmed by placental examination in all fetal cases., Conclusions: Virtopsy demonstrated a high concordance with conventional autopsy for the detection of cause of death but was less accurate for the evaluation of major pathologies. Computed tomography-guided biopsy had limited additional diagnostic value., Trial Registration: ClinicalTrials.gov (NCT01888380)., (© 2022. The Author(s).)

Aims: Somatic malignant transformation (SMT) arising in germ cell tumours (GCTs) is an infrequent, but clinically relevant event. There is only limited knowledge on the morphological spectrum of SMT, and the therapeutic management of these patients is poorly defined. In this work we revisit two consecutive case series (n = 756) of GCTs. Clinicopathological data of SMTs arising in GCTs were determined, with a focus on the histopathological spectrum, and molecular aspects were obtained by Fluorescence in situ Hybridization (FISH) and Next Generation Sequencing (NGS)., Methods and Results: Thirty male patients (28 primary testicular, two primary extragonadal) were included. These patients represent 4% of GCT patients diagnosed at two institutes (University Hospital Zurich and IPO Porto). The most common SMTs were adenocarcinoma (n = 8), embryonic-type neuroectodermal tumours (ENETs, n = 8), and rhabdomyosarcoma (n = 6), but a wide range of challenging morphologies were depicted, including low-grade neuroglial tumour, adenosquamous carcinoma, neuroblastoma, and neuroendocrine carcinoma. SMT was found in 15 primary tumour samples and in 27 metastatic samples of these 30 patients, the latter showing poorer overall survival. Adenocarcinoma occurred only in metastasis postchemotherapy and in one primary retroperitoneal GCT with SMT, but not in GCT of the testis. The 12p gains were identified by FISH in all cases. NGS results were available in six patients. Clinical trials and/or targeted treatments based on the molecular profile of SMT were recommended in four patients., Conclusions: SMT arising in GCTs represent a diagnostic challenge and should be confirmed by a specialized uropathologist. NGS-based treatment recommendations may improve the outcome of these patients., (© 2022 John Wiley & Sons Ltd.)

Sudden cardiac death (SCD) is an important public health issue. In young persons aged between 1 and 40 years, most SCDs are caused by potentially inherited cardiac diseases, often not detectable during conventional medico-legal investigations and therefore termed as sudden unexplained deaths (SUD). In this study, we describe the implementation, feasibility and importance of a standardized procedure to investigate SUD cases within the forensic framework at the Zurich Institute of Forensic Medicine in Switzerland. This new approach involves a multidisciplinary collaboration including forensic autopsy, second pathology expert opinion, post-mortem molecular genetic testing, cardiac counselling of relatives, and a tentative financing. This procedure is in line with the published Swiss and European recommendations on the management of SCDs. During a two-year pilot project, 39 sudden and unexpected death cases were collected, whereof 10 deceased remained without any identifiable cause of death after medico-legal investigation and second expert evaluation. Molecular autopsy, including 393 genes involved in cardio-vascular and metabolic diseases, identified eight pathogenic or likely pathogenic genetic variants in five out of the 10 deceased (50%). Cardio-genetic follow-up investigations in the families of the 10 deceased revealed phenotype-positive relatives in four families and required specific therapies, including an implantable cardioverter defibrillator (ICD) for primary prevention. Multidisciplinary collaboration is crucial for an optimal management of sudden unexplained death cases, to identify additional relatives at risk, and to prevent other tragic deaths within a family., Competing Interests: Declaration of Competing Interest Ardan M. Saguner received educational grants through his institution from Abbott, Bayer Healthcare, Biosense Webster, Biotronik, Boston Scientific, BMS/Pfizer, and Medtronic; and speaker fees from Bayer Healthcare, BMS/Pfizer and Daiichii Sankyo. The other authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Author(s). Published by Elsevier B.V. All rights reserved.)

Objectives: Although neonates with moderate to severe hypoxic ischemic encephalopathy (HIE) receive therapeutic hypothermia (TH), 40-50% die or have significant neurological disability. The aim of this study is to analyse the association of placental pathology and neurodevelopmental outcome in cooled neonates with HIE at 18-24 months of age., Methods: Retrospective analysis of prospectively collected data on 120 neonates registered in the Swiss National Asphyxia and Cooling Register born between 2007 and 2017. This descriptive study examines the frequency and range of pathologic findings in placentas of neonates with HIE. Placenta pathology was available of 69/120 neonates, whose results are summarized as placental findings. As neonates with HIE staged Sarnat score 1 (21/69) did not routinely undergo follow-up assessments and of six neonates staged Sarnat Score 2/3 no follow-up assessments were available, 42/48 (88%) neonates remain to assess the association between placental findings and outcome., Results: Of the 42/48 (88%) neonates with available follow up 29% (12/42) neonates died. Major placenta abnormalities occurred in 48% (20/42). Major placenta abnormality was neither associated with outcome at 18-24 months of age (OR 1.75 [95% CI 0.50-6.36, p=0.381]), nor with death by 2 years of age (OR 1.96 [95% CI 0.53-7.78, p=0.320])., Conclusions: In this study cohort there could not be shown an association between the placenta findings and the neurodevelopmental outcome at 18-24 months of age., (© 2021 Walter de Gruyter GmbH, Berlin/Boston.)

Purpose: Mesothelioma of the tunica vaginalis testis (MTVT) is a rare tumor, and currently, there are no published treatment recommendations., Methods: We performed a systematic literature review and synthesized clinical presentation, clinicopathological factors associated with metastatic disease, treatment options, and outcomes in men with MTVT., Results: We included 170 publications providing data on 275 patients. Metastatic disease occurred in 84/275 (31%) men with malignant MTVT: Most common sites included retroperitoneal lymph nodes (LNs) (40/84, 48%), lungs (30/84, 36%), and inguinal LNs (23/84, 27%). Invasion of the spermatic cord or scrotum was the only risk factor for local recurrence [odds ratio (OR) 3.21, 95% confidence interval (CI) 1.36-7.57]. Metastatic disease was associated with age ≥ 42 years (OR 3.02, 95% CI 1.33-6.86), tumor size ≥ 49 mm (OR 6.17, 95% CI 1.84-20.74), presence of necrosis (OR 8.31, 95% CI 1.58-43.62), high mitotic index (OR 13.36, 95% CI 1.53-116.51) or angiolymphatic invasion (OR 3.75, 95% CI 1.02-13.80), and local recurrence (OR 4.35, 95% CI 2.00-9.44). Complete remission in the metastatic setting was observed in five patients, most of whom were treated with multimodal therapy. Median survival in patients with metastatic disease was 18 months (IQR 7-43)., Conclusion: Malignant MTVT is a rare but aggressive disease. Since local recurrence is a risk factor for metastatic progression, we recommend aggressive local treatment. Survival and response to any treatment in the metastatic setting are limited., (© 2021. The Author(s).)

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children. Fusion-positive RMS (FPRMS), expressing the PAX3/7-FOXO1, has a worse prognosis compared to the more common fusion-negative RMS (FNRMS). Although several studies reported hierarchical organization for FNRMS with the identification of cancer stem cells, the cellular organization of FPRMS is not yet clear. In this study we investigated the expression of key stem cell markers, developed a sphere assay, and investigated the seven most common FPRMS cell lines for subpopulations of tumor propagating cancer stem-like cells, also called cancer stem cells (CSCs). Moreover, loss- and gain-of-functions of the stem cell genes SOX2, OCT4, and NANOG were investigated in the same cells. Single-cell clonal analysis was performed in vitro as well as in vivo. We found that no stable CSC subpopulation could be enriched in FPRMS. Unlike depletion of PAX3-FOXO1, neither overexpression nor siRNA-mediated downregulation of SOX2, OCT4, and NANOG affected physiology of RMS cells. Every single subclone-derived cell clone initiated tumor growth in mice, despite displaying considerable heterogeneity in gene expression. FPRMS appears to contain a high frequency of tumor propagating stem-like cells, which could explain their higher propensity for metastasis and relapse. Their dependency on PAX3-FOXO1 activity reinforces the importance of the fusion protein as the key therapeutic target.

Approximately 420 men are diagnosed with germ-cell cancer (GCC) in Switzerland each year. Recent international guidelines outline management issues, but many aspects remain controversial in an area of highly individualised treatments. Even more than in other tumour types, in GCC the challenge is to choose exactly the correct treatment for an individual patient. Overtreatment in patients likely to be cured must be avoided to reduce long-term toxicities. On the other hand, treatment intensification is required in patients presenting with adverse prognostic factors. Therefore, referral to expert centres or consultations with an expert for a second opinion is strongly recommended. In 2020, Swiss experts discussed their strategies in a consensus meeting during the virtual Swiss Oncology and Haematology Congress (SOHC) in order to harmonise their concepts and to suggest optimal strategies for the management of GCC patients in Switzerland. Votes on controversial issues were obtained and are presented in this review wherever applicable.

Embryonal rhabdomyosarcoma (ERMS) of the uterus has recently been shown to frequently harbor DICER1 mutations. Interestingly, only rare cases of extrauterine DICER1-associated ERMS, mostly located in the genitourinary tract, have been reported to date. Our goal was to study clinicopathologic and molecular profiles of DICER1-mutant (DICER1-mut) and DICER1-wild type (DICER1-wt) ERMS in a cohort of genitourinary tumors. We collected a cohort of 17 ERMS including nine uterine (four uterine corpus and five cervix), one vaginal, and seven urinary tract tumors. DNA sequencing revealed mutations of DICER1 in 9/9 uterine ERMS. All other ERMS of our cohort were DICER1-wt. The median age at diagnosis of patients with DICER1-mut and DICER1-wt ERMS was 36 years and 5 years, respectively. Limited follow-up data (available for 15/17 patients) suggested that DICER1-mut ERMS might show a less aggressive clinical course than DICER1-wt ERMS. Histological features only observed in DICER1-mut ERMS were cartilaginous nodules (6/9 DICER1-mut ERMS), in one case accompanied by foci of ossification. Recurrent mutations identified in both DICER1-mut and DICER1-wt ERMS affected KRAS, NRAS, and TP53. Copy number analysis revealed similar structural variations with frequent gains on chromosomes 2, 3, and 8, independent of DICER1 mutation status. Unsupervised hierarchical clustering of array-based whole-genome DNA methylation data of our study cohort together with an extended methylation data set including different RMS subtypes from genitourinary and extra-genitourinary locations (n = 102), revealed a distinct cluster for DICER1-mut ERMS. Such tumors clearly segregated from the clusters of DICER1-wt ERMS, alveolar RMS, and MYOD1-mutant spindle cell and sclerosing RMS. Only one tumor, previously diagnosed as ERMS arising in the maxilla of a 6-year-old boy clustered with DICER1-mut ERMS of the uterus. Subsequent sequencing analysis identified two DICER1 mutations in the latter case. Our results suggest that DICER1-mut ERMS might qualify as a distinct subtype in future classifications of RMS., (© 2021. The Author(s).)

Aims: With ongoing intensive vaccination programme against COVID-19, numerous cases of adverse reactions occur, some of which represent rare events. Enlargement of the injection site&rsquo;s draining lymph nodes is increasingly reported, but is not yet widely recognised as being possibly associated with recent vaccination. As patients at risk of a severe course of COVID-19, indicated by their medical history such as a previous diagnosis of malignancy, receive priority vaccination, newly palpable lymph nodes raise concerns of disease progression. In this case series, we report on five patients who presented with enlarged lymph nodes after COVID-19 vaccination., Methods: Sonography guided fine needle aspiration (FNA) was performed in five patients presenting with PET-positive and/or enlarged lymph nodes after COVID-19 vaccination with either the Pfizer-BioNTech or Moderna vaccine., Results: COVID-19 vaccination had been carried out in all cases, with an interval of between 3 and 33 days prior to FNA. Three of five patients had a history of neoplasms. The vaccine was administered into the deltoid muscle, with subsequent enlargement of either the cervical, supra-, infra- or retroclavicular, or axillary lymph nodes, in four out of five cases ipsilaterally. In all cases, cytology and additional analyses showed a reactive lymphadenopathy without any sign of malignancy., Conclusions: Evidence of newly enlarged lymph nodes after recent COVID-19 vaccination should be considered reactive in the first instance, occurring owing to stimulation of the immune system. A clinical follow-up according to the patient&rsquo;s risk profile without further diagnostic measures is justified. In the case of preexisting unilateral cancer, vaccination should be given contralaterally whenever possible. Persistently enlarged lymph nodes should be re-evaluated (2 to) 6 weeks after the second dose, with additional diagnostic tests tailored to the clinical context. Fine needle aspiration is a well established, safe, rapid and cost-effective method to investigate an underlying malignancy, especially metastasis. Recording vaccination history, including date of injection, site and vaccine type, as well as communicating this information to treating physicians of different specialties is paramount for properly handling COVID-19 vaccine-associated lymphadenopathy.

Overall, neonatal cancer is uncommon. Because of its rarity and heterogeneity, diagnosis can be challenging. We report a unique case of a myoepithelial carcinoma in a 7 week old girl. Molecular diagnostic workup revealed a EWSR1-KLF15 gene fusion which was previously described in only six cases of myoepithelial tumors so far. All cases occurred in children and adolescents. To our knowledge, this is the first report of a congenital EWSR1-KLF15 fusion positive myoepithelial tumor in an infant.

Diagnosis of salivary gland neoplasms is often challenging due to their high morphological diversity and overlaps. Several recurrent molecular alterations have been described recently, which can serve as powerful diagnostic tools and potential therapeutic targets (e.g. NTRK or RET fusions). However, current sequential molecular testing can be expensive and time consuming. In order to facilitate the diagnosis of salivary gland neoplasms, we designed an all-in-one RNA-based next generation sequencing panel suitable for the detection of mutations, fusions and gene expression levels (including NR4A3) of 27 genes involved in salivary gland neoplasms. Here we present the validation of the "SalvGlandDx" panel on FFPE histological specimen including fine needle aspiration (FNA) cell block material, against the standard methods currently used at our institution. In a second part we describe selected unique cases in which the SalvGlandDx panel allowed proper diagnosis and new insights into special molecular characteristics of selected salivary gland tumors. We characterize a unique salivary gland adenocarcinoma harboring a ZCCHC7-NTRK2 fusion, a highly uncommon spindle cell and pseudoangiomatoid adenoid-cystic carcinoma with MYBL1-NFIB fusion, and a purely oncocytic mucoepidermoid carcinoma, whereas diagnosis could be made by detection of a CRTC3-MAML2 rearrangement on the cell block specimen of the FNA. Further, a rare case of a SS18-ZBTB7A rearranged low-grade adenocarcinoma previously described as potential spectrum of microsecretory adenocarcinoma, is reported. In addition, features of six cases within the spectrum of polymorphous adenocarcinoma / cribriform adenocarcinoma of salivary gland including PRKD1 p.E710D mutations and novel fusions involving PRKAR2A-PRKD1, SNX9-PRKD1 and ATL2-PRKD3, are described., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Alveolar Rhabdomyosarcoma (ARMS) is an aggressive pediatric cancer with about 80% of cases characterized by either a t(1;13)(p36;q14) or t(2;13)(q35;q14), which results in the formation of the fusion oncogenes PAX7-FOXO1 and PAX3-FOXO1, respectively. Since patients with fusion-positive ARMS (FP-RMS) have a poor prognosis and are treated with an aggressive therapeutic regimen, correct classification is of clinical importance. Detection of the translocation by different molecular methods is used for diagnostics, including fluorescence in situ hybridization and RT-PCR or NGS based approaches. Since these methods are complex and time consuming, we developed specific monoclonal antibodies (mAbs) directed to the junction region on the PAX3-FOXO1 fusion protein. Two mAbs, PFM.1 and PFM.2, were developed and able to immunoprecipitate in vitro-translated PAX3-FOXO1 and cellular PAX3-FOXO1 from FP-RMS cells. Furthermore, the mAbs recognized a 105 kDa band in PAX3-FOXO1-transfected cells and in FP-RMS cell lines. The mAbs did not recognize proteins in fusion-negative embryonal rhabdomyosarcoma cell lines, nor did they recognize PAX3 or FOXO1 alone when compared to anti-PAX3 and anti-FOXO1 antibodies. We next evaluated the ability of mAb PFM.2 to detect the fusion protein by immunohistochemistry. Both PAX3-FOXO1 and PAX7-FOXO1 were detected in HEK293 cells transfected with the corresponding cDNAs. Subsequently, we stained 26 primary tumor sections and a rhabdomyosarcoma tissue array and detected both fusion proteins with a positive predictive value of 100%, negative predictive value of 98%, specificity of 100% and a sensitivity of 91%. While tumors are stained homogenously in PAX3-FOXO1 cases, the staining pattern is heterogenous with scattered positive cells only in tumors expressing PAX7-FOXO1. No staining was observed in stromal cells, embryonal rhabdomyosarcoma, and fusion-negative rhabdomyosarcoma. These results demonstrate that mAbs specific for the chimeric oncoproteins PAX3-FOXO1 and PAX7-FOXO1 can be used efficiently for simple and fast subclassification of rhabdomyosarcoma in routine diagnostics via immunohistochemical detection.

Background: Several aetiologies account for exercise intolerance, with cardiac sarcoidosis (CS) constituting a rare cause thereof. The pathogenesis of CS is still unresolved and its diagnosis still difficult to establish, in the absence of any extracardiac manifestations in particular., Case Summary: A 49-year-old amateur athlete presented with exercise intolerance during running over a 3-week period. Coronary artery and structural lung disease were excluded by coronary angiography and computer tomography. The symptoms could be reproduced during spiroergometry during which an exercise-induced high-degree atrioventricular (AV) block was documented. During electrocardiographic monitoring, a 2:1 AV block was observed. Different imaging modalities showed inferobasal septal inflammation and fibrosis. Transthoracic and transoesophageal echocardiography-guided endomyocardial biopsies were inconclusive and only subsequent epicardial biopsy performed by transdiaphragmatic minimally invasive surgery lead to the histological diagnosis of non-caseating granuloma, confirming CS. The patient was treated with high-dose steroids 1 week after implantation of a primary prevention dual-chamber implantable cardioverter-defibrillator (ICD). While tapering steroids, recurrence of myocardial inflammation occurred. However, no tachytherapies and <0.1% right ventricular pacing were needed after 2 years of follow-up., Discussion: Differential diagnoses were either an infiltrative disease, a tumour, or an infectious disease. Due to the different treatment options, we had to establish definite diagnosis by myocardial biopsy. Retrospectively, the implantation of the ICD can be discussed. However, cardiac magnetic resonance imaging showed fibrosis which is usually irreversible and substrate for potentially lethal ventricular arrhythmia. Confirming the diagnosis of isolated CS is challenging. Long-term management should be guided individually based on clinical and imaging findings., (© The Author(s) 2021. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Background: Extensive DNA sequencing has led to an unprecedented view of the diversity of individual genomes and their evolution among patients with clear cell renal cell carcinoma (ccRCC)., Objective: To understand subclonal architecture and dynamics of patient-derived two-dimensional (2D) and three-dimensional (3D) ccRCC models in vitro, in order to determine whether they mirror ccRCC inter- and intratumor heterogeneity., Design, Setting, and Participants: We have established a comprehensive platform of living renal cancer cell models from ccRCC surgical specimens., Outcome Measurements and Statistical Analysis: We confirmed the concordance of 2D and 3D patient-derived cell (PDC) models with the original tumor tissue in terms of histology, biomarker expression, cancer driver mutations, and copy number alterations. We addressed inter- and intrapatient heterogeneity by analyzing clonal dynamics during serial passaging., Results and Limitations: In-depth genetic characterization verified the presence of heterogeneous cell populations, and revealed a high degree of similarity between subclonal compositions of monolayer and organoid cell cultures and the corresponding parental ccRCCs. Clonal dynamics were evident during serial passaging of cells in vitro, suggesting that PDC cultures can offer insights into evolutionary potential and treatment susceptibility of ccRCC subclones in vivo. Proof-of-concept drug profiling using selected ccRCC-targeted therapy agents highlighted patient-specific vulnerabilities in PDC models that could not be anticipated by interrogating commercially available cell lines., Conclusions: We demonstrate that PDC models mirror inter- and intratumor heterogeneity of ccRCC in vitro. Based on our findings, we envision that the use of these models will advance our understanding of the trajectories that cause genetic diversity and their consequences for treatment on an individual level., Patient Summary: In this study, we developed two- and three-dimensional patient-derived models from clear cell renal cell carcinoma (ccRCC) as "mini-tumors in a dish." We show that these cell models retain important features of the human ccRCCs such as the profound tumor heterogeneity, thus highlighting their importance for cancer research and precision medicine., (Copyright © 2019 European Association of Urology. Published by Elsevier B.V. All rights reserved.)

Regeneration of adult skeletal muscle is driven largely by resident satellite cells, a stem cell population increasingly considered to display a high degree of molecular heterogeneity. In this study, we find that Lgr5, a receptor for Rspo and a potent mediator of Wnt/β-catenin signaling, marks a subset of activated satellite cells that contribute to muscle regeneration. Lgr5 is found to be rapidly upregulated in purified myogenic progenitors following acute cardiotoxin-induced injury. In vivo lineage tracing using our Lgr5-2ACre ERT2 R26tdTomato LSL reporter mouse model shows that Lgr5 + cells can reconstitute damaged muscle fibers following muscle injury, as well as replenish the quiescent satellite cell pool. Moreover, conditional mutation in Lgr52ACre ERT2 ;Kras G12D ;Trp53 flox/flox mice drives undifferentiated pleomorphic sarcoma formation in adult mice, thereby substantiating Lgr5 + cells as a cell of origin of sarcomas. Our findings provide the groundwork for developing Rspo/Wnt-signaling-based therapeutics to potentially enhance regenerative outcomes of skeletal muscles in degenerative muscle diseases., Competing Interests: Declaration of Interest The authors declare no competing interests., (Copyright © 2020 The Author(s). Published by Elsevier Inc. All rights reserved.)

Lung injury in mice induces mobilization of discrete subsets of epithelial progenitor cells to promote new airway and alveolar structures. However, whether similar cell types exist in human lung remains unresolved. Using flow cytometry, we identified a distinct cluster of cells expressing the epithelial cell adhesion molecule (EpCAM), a cell surface marker expressed on epithelial progenitor cells, enriched in the ecto-5'-nucleotidase CD73 in unaffected postnatal human lungs resected from pediatric patients with congenital lung lesions. Within the EpCAM + CD73 + population, a small subset coexpresses integrin β4 and HTII-280. This population remained stable with age. Spatially, EpCAM + CD73 + cells were positioned along the basal membrane of respiratory epithelium and alveolus next to CD73 + cells lacking EpCAM. Expanded EpCAM + CD73 + cells give rise to a pseudostratified epithelium in a two-dimensional air-liquid interface or a clonal three-dimensional organoid assay. Organoids generated under alveolar differentiation conditions were cystic-like and lacked robust alveolar mature cell types. Compared with unaffected postnatal lung, congenital lung lesions were marked by clusters of EpCAM + CD73 + cells in airway and cystic distal lung structures lined by simple epithelium composed of EpCAM + SCGB1A1 + cells and hyperplastic EpCAM + proSPC + cells. In non-small-cell lung cancer (NSCLC), there was a marked increase in EpCAM + CD73 + tumor cells enriched in inhibitory immune checkpoint molecules CD47 and programmed death-ligand 1 (PD-L1), which was associated with poor survival in lung adenocarcinoma (LUAD). In conclusion, EpCAM + CD73 + cells are rare novel epithelial progenitor cells in the human lung. Importantly, reemergence of CD73 in lung adenocarcinoma enriched in negative immune checkpoint molecules may serve as a novel therapeutic target.

Purpose: Testicular granulosa cell tumors (tGrCT) are rare sex cord-stromal tumors. This review aims to synthesize the available evidence regarding the clinical presentation and clinicopathological characteristics, treatment and outcomes., Methods: We conducted a systematic literature search using the most important research databases. Whenever feasible, we extracted the data on individual patient level., Results: From 7863 identified records, we included 88 publications describing 239 patients with tGrCT. The majority of the cases were diagnosed with juvenile tGrCT (166/239, 69%), while 73/239 (31%) patients were diagnosed with adult tGrCT. Mean age at diagnosis was 1.5 years (± 5 SD) for juvenile tGrCT, and 42 years (± 19 SD) for adult tGrCT. Information on primary treatment was available in 231/239 (97%), of which 202/231 (87%) were treated with a radical orchiectomy and 20/231 (9%) received testis sparing surgery (TSS). Local recurrence after TSS was observed in 1/20 (5%) cases. Metastatic disease was never observed in men with juvenile tGrCT but in 7/73 (10%) men with adult tGrCT. In 5/7 men with metastatic tGrCT, metastases were diagnosed at initial staging, while 2/7 patients developed metastases after 72 and 121 months of follow-up, respectively. Primary site of metastasis is represented by the retroperitoneal lymph nodes, but other sites including lungs, liver, bone and inguinal lymph nodes can also be affected. In comparison with non-metastatic adult tGrCT, men with metastatic adult tGrCT had significantly larger primary tumors (70 vs 24 mm, p 0.001), and were more likely to present with angiolymphatic invasion (57% vs 4%, p 0.002) or gynecomastia (29% vs 3%, p 0.019). In five out of seven men with metastatic disease, resection of metastases or platinum-based chemotherapy led to complete remission., Conclusion: Juvenile tGrCT represent a benign entity whereas adult tGCTs have metastatic potential. Tumor size, presence of angiolymphatic invasion or gynecomastia represent risk factors for metastatic disease. The published literature supports the use of testis sparing surgery but there is only limited experience with adjuvant therapies. In the metastatic setting, the reviewed literature suggests that aggressive surgical and systemic treatment might cure patients.

Hepatocyte Nuclear Factor 1 beta (HNF1β) is a transcription factor which plays an important role during early organogenesis, especially of the pancreato-biliary and urogenital tract. Furthermore, HNF1β is an established marker in the differential diagnosis of ovarian cancer and shows a distinct nuclear expression in the clear cell carcinoma subtype. Recently, it has been described in yolk sac tumor, which represents a common component in many non-seminomatous germ cell tumors. Due to its broad histologic diversity, the diagnosis may be challenging and additional tools are very helpful in the workup of germ cell tumors. Immunohistochemistry was used to study HNF1β expression in a tissue microarray (TMA) of 601 testicular germ cell tumors including seminoma, embryonal carcinoma, yolk sac tumor, choriocarcinoma, teratoma, germ cell neoplasia in situ (GCNIS), and normal tissue. The expression pattern was compared to glypican 3 (GPC3) and α-fetoprotein (AFP), two markers currently in use for the detection of yolk sac tumor. HNF1β showed a distinct nuclear staining in comparison to the cytoplasmic pattern of GPC3 and AFP. The sensitivity and specificity of HNF1β were 85.4% and 96.5%, of GPC3 83.3% and 90.7%, of AFP 62.5% and 97.7%. We conclude that HNF1β allows a reliable distinction of yolk sac tumor from other germ cell tumor components. Therefore, we propose HNF1β as a novel and robust marker in the immunohistochemical workup of testicular germ cell tumors.

Competing Interests: The authors declare no conflicts of interest.

Background: Sertoli cell tumors (SCTs) of the testes are rare, and the literature provides only weak evidence concerning their clinical course and management. The objective of this study was to summarize evidence on SCTs' clinical presentation, clinicopathological risk factors for malignancy, treatment options, and oncological outcomes., Materials and Methods: Data sources included Medline, Embase, Scopus, the Cochrane Database of Systematic Reviews, and Web of Science. Published case reports, case series, and cohorts were included. Data on clinicopathological variables, treatment of local or metastatic disease, site of metastasis, or survival were extracted from each study considered in this paper, and associations between clinicopathological variables and metastatic disease were analyzed. Whenever feasible, data on individual patients were collected., Results: Of the 435 patients included, only one (<1%) showed local recurrence after testis-sparing surgery (TSS). Three patients underwent adjuvant retroperitoneal lymphadenectomy. Fifty patients presented with metastases, located in the retroperitoneal lymph nodes (76%), lungs (36%), and bones (16%); median time to recurrence was 12 months. Risk factors for metastatic disease included age, tumor size, necrosis, tumor extension to the spermatic cord, angiolymphatic invasion, and mitotic index. Patients with metastases had a median life expectancy of 20 months. In six patients, metastasectomy resulted in complete remission., Conclusion: Our findings suggest that few local recurrences result after TSS, and no adjuvant therapy can be regarded as a standard of care. Several risk factors are predictive of metastatic disease. Surgery leads to remission in metastatic disease, whereas systemic treatment alone does not result in long-term remission., Implications for Practice: Testicular Sertoli cell tumors usually present without metastatic disease and show low local recurrence rates after testis-sparing surgery; no adjuvant therapy option can be regarded as a standard of care. Patients with risk factors should undergo staging investigations. Those with metastatic disease have poor prognoses, and metastasectomy may be offered in selected cases., (© AlphaMed Press 2020.)

Background: A radiation-free advanced imaging modality is desirable for investigating congenital thoracic malformations in young children., Objective: To describe magnetic resonance imaging (MRI) findings of congenital bronchopulmonary foregut malformations and investigate the ability of lung MRI for their classification., Materials and Methods: This is a retrospective analysis of consecutive MRI examinations performed for suspected congenital lung anomalies in 39 children (median age: 3.8 months, range: 2 days-15 years). Morphological and perfusion findings were characterised on respiratory-gated fast spin echo and dynamic contrast-enhanced sequences obtained at 1.5 tesla. Abnormalities were classified independently by two readers and compared to an expert diagnosis based on pathology, surgery and/or other imaging., Results: Main diagnoses included bronchopulmonary lesions in 33 patients, scimitar syndrome in 4 patients, pulmonary arteriovenous malformation and oesophageal duplication cyst in one patient each. Of 46 observed abnormalities, 44 (96%) were classified correctly with very good interobserver agreement (96% concordance rate). The 39 detected lung lesions included isolated overinflation (17/39, 44%), cystic pulmonary airway malformation (8/39, 21%), bronchopulmonary sequestration (7/39, 18%), bronchogenic cyst (4/39, 10%) and hybrid lesion (3/39, 8%). All lung lesions presented as perfusion defect at peak pulmonary enhancement. Non-cystic lesions showed a delayed peak (median delay: 2.8 s, interquartile range: 0.5 to 4.0 s) in relation to normal lung parenchyma., Conclusion: A dedicated lung MRI protocol including respiratory compensated sequences, dynamic angiography and perfusion is able to reliably delineate parenchymal and vascular components of congenital bronchopulmonary foregut malformations. Therefore, MRI may be considered for comprehensive postnatal evaluation of congenital thoracic malformations.

Neuroblastoma (NB) is the most common cancer in infants and it accounts for six percent of all pediatric malignancies. There are several hypotheses proposed on the origins of NB. While there is little genetic evidence to support this, the prevailing model is that NB originates from neural crest stem cells (NCSCs). Utilizing in vivo mouse models, we demonstrate that targeting MYCN oncogene to NCSCs causes perinatal lethality. During sympathoadrenal (SA) lineage development, SOX transcriptional factors drive the transition from NCSCs to lineage-specific progenitors, characterized by the sequential activation of Sox9/Sox10/Sox4/Sox11 genes. We find the NCSCs factor SOX10 is not expressed in neuroblasts, but rather restricted to the Schwannian stroma and is associated with a good prognosis. On the other hand, SOX9 expression in NB cells was associated with several key biological processes including migration, invasion and differentiation. Moreover, manipulating SOX9 gene predominantly affects lineage-restricted SA progenitors. Our findings highlight a unique molecular SOX signature associated with NB that is highly reminiscent of SA progenitor transcriptional program during embryonic development, providing novel insights into NB pathobiology. In summary, we provide multiple lines of evidence suggesting that multipotent NCSCs do not contribute to NB initiation and maintenance., Competing Interests: CONFLICTS OF INTEREST Authors declare no competing interests., (Copyright: © 2020 Yang et al.)

Purpose: Leydig cell tumors are rare but they are the most common nongerm cell testicular tumors. Only limited evidence exists for reliably differentiating between benign and malignant Leydig cell tumors and for optimally managing the different types and stages of this rare disease. In this review we synthesize the available evidence on the clinical presentation and clinicopathological characteristics associated with Leydig cell tumor malignancy and management., Materials and Methods: We analyzed published case series data on Leydig cell tumors. The association between clinicopathological variables and the presence of metastatic disease was assessed using regression analyses., Results: We included 357 reports, reviewing available data from 1,375 patients (median age 34 years). Testis sparing surgery was performed in 463 patients. Local recurrence after testis sparing surgery occurred in 8 of 121 (7%) patients with available followup information. Metastases were found in 101 patients and were most often located in the retroperitoneal lymph nodes (60%), lungs (38%) and/or liver (29%). The multivariable models with or without multiple imputation predicting metastatic disease included older age, larger tumor size, presence of any adverse factor (larger tumor diameter, necrosis, angiolymphatic invasion, pleomorphism, high mitotic index, atypia) and any protective factor (Reinke crystals, lipofuscin pigments, gynecomastia) with model AUCs of 0.93. Durable remission after resection of metastases or use of platinum based chemotherapy was rarely seen., Conclusions: Our risk tables using clinicopathological parameters can help identify patients with malignant tumors. These patients should undergo disease staging and be followed or receive further treatment. In some patients with metastatic disease surgical and systemic treatment might result in disease control.

Our understanding of mesenchymal cell subsets and their function in human lung affected by aging and in certain disease settings remains poorly described. We use a combination of flow cytometry, prospective cell-sorting strategies, confocal imaging, and modeling of microvessel formation using advanced microfluidic chip technology to characterize mesenchymal cell subtypes in human postnatal and adult lung. Tissue was obtained from patients undergoing elective surgery for congenital pulmonary airway malformations (CPAM) and other airway abnormalities including chronic obstructive pulmonary disease (COPD). In microscopically normal postnatal human lung, there was a fivefold higher mesenchymal compared with epithelial (EpCAM + ) fraction, which diminished with age. The mesenchymal fraction composed of CD90 + and CD90 + CD73 + cells was enriched in CXCL12 and platelet-derived growth factor receptor-α (PDGFRα) and located in close proximity to EpCAM + cells in the alveolar region. Surprisingly, alveolar organoids generated from EpCAM + cells supported by CD90 + subset were immature and displayed dysplastic features. In congenital lung lesions, cystic air spaces and dysplastic alveolar regions were marked with an underlying thick interstitium composed of CD90 + and CD90 + PDGFRα + cells. In postnatal lung, a subset of CD90 + cells coexpresses the pericyte marker CD146 and supports self-assembly of perfusable microvessels. CD90 + CD146 + cells from COPD patients fail to support microvessel formation due to fibrinolysis. Targeting the plasmin-plasminogen system during microvessel self-assembly prevented fibrin gel degradation, but microvessels were narrower and excessive contraction blocked perfusion. These data provide important new information regarding the immunophenotypic identity of key mesenchymal lineages and their change in a diverse setting of congenital lung lesions and COPD.

Glycogen storage disease type VI (GSD-VI; also known as Hers disease, liver phosphorylase deficiency) is caused by mutations in the gene coding for glycogen phosphorylase (PYGL) leading to a defect in the degradation of glycogen. Since there are only about 40 patients described in literature, our knowledge about the course of the disease is limited. In order to evaluate the long-term outcome of patients with GSD-VI, an observational retrospective case study of six patients was performed at the University Children's Hospital Zurich. The introduction of small, frequent meals as well as cornstarch has led to normal growth in all patients and to normalization of liver transaminases in most patients. After starting the dietary regimen, there were no signs of hypoglycemia. However, three of six patients showed persistent elevation of triglycerides. Further, we identified four novel pathogenic PYGL mutations and describe here their highly variable impact on phosphorylase function.Conclusions: After establishing the diagnosis, dietary treatment led to metabolic stability and to prevention of hypoglycemia. Molecular genetics added important information for the understanding of the clinical variability in this disease. While outcome was overall excellent in all patients, half of the patients showed persistent hypertriglyceridemia even after initiating treatment.What is Known:• Glycogen storage disease type VI (GSD-VI) is a metabolic disorder causing a defect in glycogen degradation. Dietary treatment normally leads to metabolic stability and prevention of hypoglycemia.• However, our knowledge about the natural course of patients with GSD-VI is limited.What is New:• While outcome was overall excellent in all patients, half of the patients showed persistent hypertriglyceridemia even after initiating treatment.• Molecular genetics added important information for the understanding of the clinical variability in this disease.

Introduction: Because spermatocytic tumors of the testis are rare, only limited evidence exists regarding the malignant potential and the optimal management of localized and metastatic disease., Materials and Methods: We performed a systematic review through MEDLINE, EMBASE, Scopus, Cochrane Database of Systematic Reviews and Web of Science to identify reports including patients with testicular spermatocytic tumors., Results: From originally 7863 studies, we extracted data of 146 patients of which 99% were treated with radical orchiectomy. Metastases in patients with initially localised disease were diagnosed in 7% of patients and detected after a median follow-up of 5.5 months (range 2-21 months). Patients with aggressive histology (sarcoma or anaplastic subtype) were more likely to have metastatic disease (6/124 (5%) vs 9/22 (41%), p < 0.001). Patients with metastatic disease had larger primary tumors (92.5 vs 67.5 mm, p = 0.05). Life expectancy in patients with metastatic disease ranged from 1 to 25 months., Conclusion: The published literature does neither support the use of testis sparing surgery nor adjuvant therapy. Patients with aggressive variants or larger tumors were more likely to have metastases and develop recurrences within the first few years. Patients with metastatic disease have a limited life expectancy and metastatic spermatocytic tumors are not as responsive to chemotherapy as germ cell cancers.

Background: To validate the utility of the chemokine ligand 12 (CXCL12) as prognostic marker in patients with localized and metastatic germ cell tumors (GCT)., Methods: CXCL12 expression was analyzed on a tissue microarray consisting of 750 tissue cores of different histological tumor components, Germ cell neoplasia in situ (GCNIS) and adjacent normal tissue of 263 testicular cancer patients using a semi-quantitative score. The association between CXCL12 expression and recurrence-free survival (RFS) as well as overall survival (OS) was assessed using Kaplan-Meier curves with log-rank tests., Results: CXCL12 expression was absent in all seminomas but was found in 52 of 99 (52.5%) non-seminomas. Follow-up was available for 260 patients of which 36 (13.8%) recurred. In patients with stage 1 non-seminoma GCT, CXCL12 expression was not associated with higher risk of disease recurrence (p = 0.270). In contrast, post chemotherapy RFS of patients with metastatic non-seminoma and positive CXCL12 expression was significantly shorter compared to CXCL12 negative patients (p = 0.003). OS differences were not statistically different between patients with CXCL12 positive or negative tumors for either localized or metastatic disease., Conclusions: CXCL12 is almost exclusively expressed in non-seminoma. Pure seminoma, GCNIS and adjacent normal testicular tissue are CXCL12 negative. Our analysis suggests that patients with metastatic disease and a CXCL12-positive non-seminoma are at higher risk for disease recurrence after first-line chemotherapy and might thus be candidates for more intensive treatment and/or closer follow-up.

Background: Atrial fibrillation (AF) is the most common atrial arrhythmia in arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVD). Considering the histologic changes known in the right ventricular (RV) in ARVD, the aim of the present study was to examine right atrial (RA) pathology in patients with ARVD., Methods: Histology of RA and RV was assessed from autopsy material in 3 patients with ARVD without persistent atrial arrhythmia. RA histology in 3 patients with permanent AF without ARVD and 5 patients without cardiovascular disease was also studied. Staining with hematoxylin phloxine saffron was performed for the ARVD patients to identify fibrosis, and hematoxylin-eosin for identification of lymphocytes. Masson's trichrome staining was performed for control groups taken from a collection of standard glass slides., Results: In all 3 ARVD cases, RA anomalies were observed that revealed a reduction of cardiomyocytes, the presence of adipocytes, some of them inside the mediomural atrial layer and interstitial fibrosis. In 2 ARVD cases, interstitial fibrosis was also associated with a focus of replacement fibrosis, which was also observed in patients with permanent AF without ARVD. The histologic specimen of the RA and RV from the control group without cardiovascular disease did not display any evidence of fat or fibrosis with a preserved cardiomyocyte architecture., Conclusions: A similar histopathological substrate, as can be observed in the RV of patients with ARVD can also be seen in the RA of these patients. This may explain the high prevalence of atrial arrhythmias, particularly AF, in patients with ARVD.

Following publication of the original article [1], we have been alerted to errors in Figs. 2 and 8. In Fig. 2B, the GAPDH loading control for Hec1A cells is shown twice in error (in Fig. 2B and Fig. 2C). In Fig. 8, in testis case 1 (first column) the MAGE-A4 staining panel was repeated and also appears as the NY-ESO-1 staining panel in error. The corrected versions of Fig. 2 and Fig. 8 are shown below. We apologize for this inconvenience.

Background: The reconstruction of heart valves provides substantial benefits, particularly in the pediatric population. We present our experience using decellularized extracellular matrix (dECM, CorMatrix ® ) for aortic valve procedures., Methods: We retrospectively reviewed the case histories of 6 patients (aged from 2 months - 14 years) who underwent surgery for severe aortic valve stenosis (n = 4) or regurgitation (n = 2). Aortic valve repair was performed on all patients using dECM as a leaflet replacement or leaflet extension. Follow-ups were performed using echocardiography. Reoperation was necessary in 4 cases, and the dECM was explanted and examined histologically and immunohistochemically., Results: The early post-operative period was uneventful, and the scaffold fulfilled the mechanical requirements. Significant valve insufficiency developed in 5 patients during the post-operative period (119-441 days postoperatively). In all specimens, only a migration of inflammatory cells was identified, which induced structural and functional changes caused by the chronic inflammatory response., Conclusions: Our results suggest a mixed immunological response of remodeling and inflammation following the implantation. The expected process of seeding/migration and remodeling of the bioscaffold into the typical 3-layered architecture were not observed in our explanted specimens., (© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)