Lymph Node Staging and Treatment in Pediatric Patients With Soft Tissue Sarcomas: A Consensus Opinion from the Children's Oncology Group, European paediatric Soft tissue sarcoma Study Group, and the Cooperative Weichteilsarkom Studiengruppe.

Accurate staging of nodal involvement in pediatric sarcoma patients is important to determine correct systemic and local therapy, with the goal to reduce subsequent recurrences. However, differences in lymph node staging strategies, definitions, and treatment protocols between the Children's Oncology Group (COG), European paediatric Soft tissue sarcoma Study Group (EpSSG), and the Cooperative Weichteilsarkom Studiengruppe (CWS) complicate comparisons. In this article, we aim to establish internationally recognized recommendations for lymph node assessment and treatment of children and adolescents diagnosed with rhabdomyosarcoma (RMS) and non-rhabdomyosarcoma soft tissue sarcoma (NRSTS) according to the Consensus Conference Standard Operating Procedure methodology.

Helicobacter pylori infection is associated with significant elevations to fecal calprotectin, systemic inflammatory markers.

Objectives: Fecal calprotectin (FC) is a marker commonly used in the diagnosis and follow-up of inflammatory bowel diseases (IBD). However, other gastrointestinal conditions, like H. pylori (HP) infection, can result in increased neutrophil activity as well.

Increased SOX10, p16, and Cyclin D1 Immunoreactivity Differentiates MAP Kinase-activated Low-grade Gliomas From Piloid Gliosis.

Low-grade gliomas and reactive piloid gliosis can present with overlapping features on conventional histology. Given the large implications for patient treatment, there is a need for effective methods to discriminate these morphologically similar but clinically distinct entities. Using routinely available stains, we hypothesize that a limited panel including SOX10, p16, and cyclin D1 may be useful in differentiating mitogen-activated protein (MAP) kinase-activated low-grade gliomas from piloid gliosis.

Pictorial review: challenges in distinguishing bilateral metaphyseal marrow abnormalities on magnetic resonance imaging.

The paediatric metaphysis is afflicted by a wide range of pathological processes as it is the most metabolically active and well-vascularised part of the developing skeleton. This review focuses on metaphyseal marrow signal change detected with magnetic resonance imaging, which is most often occult on radiographs. When bilateral, these imaging appearances frequently present a diagnostic quandary.

Neuropathological Applications of Microscopy with Ultraviolet Surface Excitation (MUSE): A Concordance Study of Human Primary and Metastatic Brain Tumors.

Whereas traditional histology and light microscopy require multiple steps of formalin fixation, paraffin embedding, and sectioning to generate images for pathologic diagnosis, Microscopy using Ultraviolet Surface Excitation (MUSE) operates through UV excitation on the cut surface of tissue, generating images of high resolution without the need to fix or section tissue and allowing for potential use for downstream molecular tests. Here, we present the first study of the use and suitability of MUSE microscopy for neuropathological samples. MUSE images were generated from surgical biopsy samples of primary and metastatic brain tumor biopsy samples (n = 27), and blinded assessments of diagnoses, tumor grades, and cellular features were compared to corresponding hematoxylin and eosin (H&E) images.

Indeterminate pulmonary nodules in non-rhabdomyosarcoma soft tissue sarcoma: A study of the European paediatric Soft Tissue Sarcoma Study Group.

Background: The aim of this study was to assess the clinical impact of indeterminate pulmonary nodules (no more than four pulmonary nodules of less than 5 mm or one nodule measuring between 5 and less than 10 mm by computed tomography [CT]) in children and adolescents with adult-type non-rhabdomyosarcoma soft tissue sarcoma (NRSTS) at diagnosis.

Methods: Patients with NRSTS treated in 11 centers as part of the European paediatric Soft Tissue Sarcoma Study Group (EpSSG) were retrospectively assessed. Local radiologists, blinded to clinical information except for patients' age and tumor histotype, reviewed the chest CT at diagnosis and filled out a case report form.

Epidemiologic Assessment of Pediatric Inflammatory Bowel Disease Presentation in NYC During COVID-19.

Inflammatory bowel disease (IBD) pathogenesis is thought to be induced by a mix of genetic susceptibility, microbial populations, and immune triggers such as infections. Severe acute respiratory syndrome coronavirus 2 (SARS-nCoV2) may have increased capacity to generate autoimmune disease as evidenced by known spikes in diseases such as type 1 diabetes mellitus. Public health interventions like masking and closures additionally created remarkable drops in typical viral infections, with remarkable shifts in influenza-like illness reporting in 2020.

Synaptopodin stress fiber and contractomere at the epithelial junction.

The apical junction of epithelial cells can generate force to control cell geometry and perform contractile processes while maintaining barrier function and adhesion. Yet, the structural basis for force generation at the apical junction is not fully understood. Here, we describe two synaptopodin-dependent actomyosin structures that are spatially, temporally, and structurally distinct.

Appendiceal involvement in pediatric inflammatory multisystem syndrome temporally associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2): a diagnostic challenge in the coronavirus disease (COVID) era.

Background: Many studies on pediatric inflammatory multisystem syndrome temporally associated with severe acute respiratory syndrome coronavirus 2 (PIMS-TS) have described abdominal findings as part of multisystem involvement, with limited descriptions of abdominal imaging findings specific to PIMS-TS.

Objective: To perform a detailed evaluation of abdominal imaging findings in children with PIMS-TS.

Materials And Methods: We performed a single-center retrospective study of children admitted to our institution between April 2020 and January 2021 who fulfilled Royal College of Paediatrics and Child Health criteria for PIMS-TS and who had cross-sectional abdominal imaging.

Location, symptoms, and management of plexiform neurofibromas in 127 children with neurofibromatosis 1, attending the National Complex Neurofibromatosis 1 service, 2018-2019.

We report on the location, symptoms, and management of plexiform neurofibroma (PN) in children with Neurofibromatosis Type 1 (NF1) attending the 2 National Complex Neurofibromatosis 1 Services at Guy's and St. Thomas' NHS Foundation Trust, London and St Mary's Hospital, Manchester. Retrospective data collection was performed from patient chart reviews from April 2018 to April 2019.

Spectrum of anatomical variants, normal findings and pathology in and around the paediatric sternum.

Abnormalities of the sternum and adjacent structures are an uncommon presentation in the paediatric population and can have a variety of benign and malignant causes, including normal and developmental variants of the chest wall. Although there is overlap with adults, many sternal abnormalities are unique to the paediatric population. Following clinical examination, radiography is usually the first type of imaging used; however, it is limited and often ultrasound and cross-sectional imaging are needed for further assessment.

Nests of dividing neuroblasts sustain interneuron production for the developing human brain.

The human cortex contains inhibitory interneurons derived from the medial ganglionic eminence (MGE), a germinal zone in the embryonic ventral forebrain. How this germinal zone generates sufficient interneurons for the human brain remains unclear. We found that the human MGE (hMGE) contains nests of proliferative neuroblasts with ultrastructural and transcriptomic features that distinguish them from other progenitors in the hMGE.

Embryonal sarcoma of the liver in a girl with Cockayne syndrome.

The first reported malignancy associated with Cockayne syndrome.

Cadherin puncta are interdigitated dynamic actin protrusions necessary for stable cadherin adhesion.

Cadherins harness the actin cytoskeleton to build cohesive sheets of cells using paradoxically weak bonds, but the molecular mechanisms are poorly understood. In one popular model, actin organizes cadherins into large, micrometer-sized clusters known as puncta. Myosin is thought to pull on these puncta to generate strong adhesion.

Congenital presentation of synchronous Atypical Teratoid Rhabdoid Tumor and Malignant Rhabdoid Tumor of the urinary bladder in a term infant.

Atypical teratoid/rhabdoid tumor (AT/RT) is a rare central nervous system (CNS) tumor diagnosed primarily in infants and usually portends a poor prognosis. Despite being the most common embryonal tumor in children less than 1 year old, diagnosis is difficult to make based on clinical findings or imaging alone. A complete diagnosis of AT/RT requires identification of loss of integrase interactor 1 (INI1) protein or the SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily b, member 1 () gene, in its most common presentation.

Constitutional de novo deletion CNV encompassing predisposes to diffuse hyperplastic perilobar nephroblastomatosis (HPLN).

Background: Nephroblastomatosis is a recognised precursor for the development of Wilms tumour (WT), the most common childhood renal tumour. While the majority of WT is sporadic in origin, germline intragenic mutations of predisposition genes such as , and have been described in apparently isolated (non-familial) WT.Despite constitutional CNVs being a well-studied cause of developmental disorders, their role in cancer predisposition is less well defined, so that the interpretation of cancer risks associated with specific CNVs can be complex.

Collagen, stiffness, and adhesion: the evolutionary basis of vertebrate mechanobiology.

The emergence of collagen I in vertebrates resulted in a dramatic increase in the stiffness of the extracellular environment, supporting long-range force propagation and the development of low-compliant tissues necessary for the development of vertebrate traits including pressurized circulation and renal filtration. Vertebrates have also evolved integrins that can bind to collagens, resulting in the generation of higher tension and more efficient force transmission in the extracellular matrix. The stiffer environment provides an opportunity for the vertebrates to create new structures such as the stress fibers, new cell types such as endothelial cells, new developmental processes such as neural crest delamination, and new tissue organizations such as the blood-brain barrier.

Catastrophic actin filament bursting by cofilin, Aip1, and coronin.

Cofilin is an actin filament severing protein necessary for fast actin turnover dynamics. Coronin and Aip1 promote cofilin-mediated actin filament disassembly, but the mechanism is somewhat controversial. An early model proposed that the combination of cofilin, coronin, and Aip1 disassembled filaments in bursts.

Neurological Etiologies and Pathophysiology of Cyclic Vomiting Syndrome.

Cyclic vomiting syndrome is an idiopathic chronic periodic disorder of childhood which may persist into the adult years. Although cyclic vomiting syndrome is considered a central nervous system disorder, it is often managed by a pediatric gastroenterologist. The practitioner should not assume a gastrointestinal or non-neurological cause of symptoms especially if there are coexisting neurological symptoms and signs or if vomiting does not bring relief; this suggests a possible central nervous system cause, which may necessitate a pediatric neurology consultation.

Actin protrusions push at apical junctions to maintain E-cadherin adhesion.

Cadherin-mediated cell-cell adhesion is actin-dependent, but the precise role of actin in maintaining cell-cell adhesion is not fully understood. Actin polymerization-dependent protrusive activity is required to push distally separated cells close enough to initiate contact. Whether protrusive activity is required to maintain adhesion in confluent sheets of epithelial cells is not known.

Cell-cell adhesion interface: orthogonal and parallel forces from contraction, protrusion, and retraction.

The epithelial lateral membrane plays a central role in the integration of intercellular signals and, by doing so, is a principal determinant in the emerging properties of epithelial tissues. Mechanical force, when applied to the lateral cell-cell interface, can modulate the strength of adhesion and influence intercellular dynamics. Yet the relationship between mechanical force and epithelial cell behavior is complex and not completely understood.

Myosin-1c promotes E-cadherin tension and force-dependent recruitment of α-actinin to the epithelial cell junction.

Actomyosin II contractility in epithelial cell plays an essential role in tension-dependent adhesion strengthening. One key unsettling question is how cellular contraction transmits force to the nascent cell-cell adhesion when there is no stable attachment between the nascent adhesion complex and actin filament. Here, we show that myosin-1c is localized to the lateral membrane of polarized epithelial cells and facilitates the coupling between actin and cell-cell adhesion.