Atypical Neuroblastoma With Absent Urinary Catecholamine Excretion and ImIBG Avidity Are of Favorable Outcome: A Retrospective French Single-Center Study.

Background: In neuroblastoma (NB), urinary catecholamine excretion and ImIBG avidity-depending on tumor enzymatic activity and norepinephrine transporter expression, respectively-are diagnostic standards. The prognostic impact of atypical NB, without urinary catecholamine excretion and/or ImIBG avidity, remains to be determined. We sought to determine the frequency and prognosis of atypical NB and investigate the significance of catecholamine profiles and ImIBG avidity at diagnosis.

Practical guidelines on imaging of retinoblastoma: a 2025 update on behalf of the European Retinoblastoma Imaging Collaboration and the European Retinoblastoma Group.

Retinoblastoma is the most common intraocular malignancy in children. Imaging plays a crucial role in evaluating children with retinoblastoma, both to determine tumor extension and to confirm the diagnosis when necessary. The eighth edition of the American Joint Committee on Cancer (TNM) classification provides a comprehensive intraocular and extraocular staging for retinoblastoma, with a key role for imaging, particularly in cases of advanced tumors.

SMARCB1-deficient malignant melanocytic uveal tumours: a new neural crest-derived tumour entity with SMARCB1-related germline predisposition.

Rhabdoid tumours (RT) are an aggressive malignancy affecting <2-year-old infants, characterised by biallelic loss-of-function alterations in SWI/SNF-related BAF chromatin remodelling complex subunit B1 (SMARCB1) in nearly all cases. Germline SMARCB1 alterations are found in ~30% of patients and define the RT Predisposition Syndrome type 1 (RTPS1). Uveal melanoma (UVM), the most common primary intraocular cancer in adults, does not harbour SMARCB1 alterations.

Ultrasound-guided core-needle biopsy for extra-ocular orbital soft tissue tumours: a minimally invasive alternative to surgical biopsy.

Objective: To assess the feasibility, accuracy, and safety of ultrasound (US)-guided coaxial core-needle biopsy (CNB) for histomolecular diagnosis of extra-ocular orbital soft tissue tumours as a minimally invasive alternative to surgical biopsy.

Methods: This retrospective study was conducted at a single Comprehensive Cancer Center and included all consecutive patients referred to our center between 2015 and 2023 for the diagnosis and treatment of orbital soft tissue tumours. All patients underwent US-guided transconjunctival coaxial CNB using a semiautomatic 18-gauge biopsy gun.

Differentiating MYCN-amplified RB1 wild-type retinoblastoma from biallelic RB1 mutant retinoblastoma using MR-based radiomics: a retrospective multicenter case-control study.

MYCN-amplified RB1 wild-type (MYCNRB1) retinoblastoma is a rare and aggressive subtype, often resistant to standard therapies. Identifying unique MRI features is crucial for diagnosing this subtype, as biopsy is not recommended. This study aimed to differentiate MYCNRB1 from the most prevalent RB1 retinoblastoma using pretreatment MRI and radiomics.

Expanding the clinicopathologic spectrum and genomic landscape of tumors with SMARCA2/4::CREM fusions.

CREB gene family (ATF1, CREB1, CREM) fusions with either EWSR1 or FUS gene partners drive the pathogenesis of a wide range of neoplasms, including various soft tissue tumors, intracranial myxoid mesenchymal tumors (IMMTs), hyalinizing clear cell carcinoma (HCCC), and rare mesotheliomas. Recently, a SMARCA2::CREM fusion was reported in one case each of IMMT and HCCC. In this study, we expand the clinicopathologic and molecular spectrum of these neoplasms by describing three additional cases with SMARCA2::CREM and one with a novel SMARCA4::CREM fusion, highlighting the recurrent potential of additional CREB gene fusion partners beyond FET family members.

MR Imaging of Adverse Effects and Ocular Growth Decline after Selective Intra-Arterial Chemotherapy for Retinoblastoma.

This retrospective multicenter study examines therapy-induced orbital and ocular MRI findings in retinoblastoma patients following selective intra-arterial chemotherapy (SIAC) and quantifies the impact of SIAC on ocular and optic nerve growth. Patients were selected based on medical chart review, with inclusion criteria requiring the availability of posttreatment MR imaging encompassing T2-weighted and T1-weighted images (pre- and post-intravenous gadolinium administration). Qualitative features and quantitative measurements were independently scored by experienced radiologists, with deep learning segmentation aiding total eye volume assessment.

Imaging characterization of paediatric tumours with the neurotrophic tyrosine receptor kinase fusion transcript.

Objectives: The neurotrophic tyrosine receptor kinase (NTRK) fusion transcript (FT) is a major genetic landmark of infantile fibrosarcoma (IFS) and cellular congenital mesoblastic nephroma (cCMN) but is also described in other tumours. The recent availability of NTRK-targeted drugs enhances the need for better identification. We aimed to describe the anatomic locations and imaging features of tumours with NTRK-FT in children.

Optic nerve thickening on high-spatial-resolution MRI predicts early-stage postlaminar optic nerve invasion in retinoblastoma.

Objectives: To assess the diagnostic accuracy of nerve thickening on MRI to predict early-stage postlaminar optic nerve invasion (PLONI) in retinoblastoma. Furthermore, this study aimed to incorporate measurements into a multiparametric model for radiological determination of PLONI.

Methods: In this retrospective multicenter case-control study, high-spatial-resolution 3D T2-weighted MR images were used to measure the distal optic nerve.

Diffuse Infiltrating Retinoblastoma with Anterior Chamber Involvement: Conservative Management and Identification of Alterations in Aqueous Humor.

Introduction: The aim of the study was to describe the successful conservative management of diffuse infiltrating retinoblastoma (DIR). Identification of pathogenic variant was done after cell-free DNA (cfDNA) analysis in aqueous humor.

Case Presentation: Herein, we report 2 patients with unilateral, non-familial DIR with anterior and posterior involvement.

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.

Correlation of gene expression with magnetic resonance imaging features of retinoblastoma: a multi-center radiogenomics validation study.

Objectives: To validate associations between MRI features and gene expression profiles in retinoblastoma, thereby evaluating the repeatability of radiogenomics in retinoblastoma.

Methods: In this retrospective multicenter cohort study, retinoblastoma patients with gene expression data and MRI were included. MRI features (scored blinded for clinical data) and matched genome-wide gene expression data were used to perform radiogenomic analysis.

Fat-Containing Soft Tissue Tumors in Children, Adolescents, and Young Adults: Which Require Biopsy?

Purpose: To confirm the overall benignity of fat-containing soft tissue tumors (STT) on a pediatric cohort and to define the clinical and imaging features that warrant a biopsy.

Methods: A retrospective monocentric study was conducted on patients aged less than 25 years consecutively referred for fat-containing STT to our Comprehensive Cancer Center between 1998 and 2022. Tumor imaging characteristics at diagnosis (US, CT, or MRI) were correlated with pathology.

MRI Features for Identifying -amplified Wild-type Retinoblastoma.

Background -amplified wild-type () retinoblastoma is a rare but clinically important subtype of retinoblastoma due to its aggressive character and relative resistance to typical therapeutic approaches. Because biopsy is not indicated in retinoblastoma, specific MRI features might be valuable to identify children with this genetic subtype. Purpose To define the MRI phenotype of retinoblastoma and evaluate the ability of qualitative MRI features to help identify this specific genetic subtype.

How can we differentiate supratentorial tumor recurrence from postradiation imaging changes in children treated for primary malignant brain tumors?

Objective: Distinguishing tumor recurrence from therapy-induced imaging changes (TIIC) on brain MRI in children treated for primary malignant brain tumors may be challenging. The authors aimed to assess the diagnostic ability of multimodal MRI in differentiating TIIC from tumor recurrence.

Methods: The authors retrospectively included children with abnormal supratentorial brain MRI findings after treatment for primary malignant brain tumors (regardless of their localization) with complete resection and radiotherapy.

NTRK-rearranged spindle cell neoplasms are ubiquitous tumours of myofibroblastic lineage with a distinct methylation class.

Aims: NTRK gene fusions have been described in a wide variety of central nervous system (CNS) and soft tissue tumours, including the provisional tumour type 'spindle cell neoplasm, NTRK-rearranged' (SCN-NTRK), added to the 2020 World Health Organisation Classification of Soft Tissue Tumours. Because of histopathological and molecular overlaps with other soft tissue entities, controversy remains concerning the lineage and terminology of SCN-NTRK.

Methods And Results: This study included 16 mesenchymal tumours displaying kinase gene fusions (NTRK fusions and one MET fusion) initially diagnosed as infantile fibrosarcomas (IFS), SCN-NTRK and adult-type fibrosarcomas from the soft tissue, viscera and CNS.

Imaging of Pediatric Testicular and Para-Testicular Tumors: A Pictural Review.

Pre- and post-pubertal testicular tumors are two distinct entities in terms of epidemiology, diagnosis and treatment. Most pre-pubertal tumors are benign; the most frequent are teratomas, and the most common malignant tumors are yolk-sac tumors. Post-pubertal tumors are similar to those found in adults and are more likely to be malignant.

Magnetic Resonance Imaging Can Reliably Differentiate Optic Nerve Inflammation from Tumor Invasion in Retinoblastoma with Orbital Cellulitis.

Purpose: To investigate the prevalence and magnetic resonance imaging (MRI) phenotype of retinoblastoma-associated orbital cellulitis. Additionally, this study aimed to identify postlaminar optic nerve enhancement (PLONE) patterns differentiating between inflammation and tumor invasion.

Design: A monocenter cohort study assessed the prevalence of orbital cellulitis features on MRI in retinoblastoma patients.

NUT carcinoma in children, adolescents and young adults.

Background: NUT carcinoma (NC), defined by the presence of the NUTM1 rearrangement, is an aggressive tumour associated with poor prognosis. This rare cancer is underdiagnosed and difficult to treat.

Objective And Methods: The primary objective of this review is to describe the clinical, radiological and laboratory features of NC in young patients.

Intra- and extra-cranial BCOR-ITD tumours are separate entities within the BCOR-rearranged family.

BCOR-ITD tumours form an emerging family of aggressive entities with an internal tandem duplication (ITD) in the last exon of the BCOR gene. The family includes cerebral tumours, termed central nervous system BCOR-ITD (CNS BCOR-ITD), and sarcomatous types described in the kidney as clear cell sarcoma of the kidney (CCSK), in the endometrium as high-grade endometrial stromal sarcoma, and in the bone and soft tissue as undifferentiated round cell sarcoma or primitive myxoid mesenchymal tumour of infancy. Based on a series of 33 retrospective cases, including 10 CNS BCOR-ITD and 23 BCOR-ITD sarcomas, we interrogated the homogeneity of the entity regarding clinical, radiological, and histopathological findings, and molecular signatures.

Infantile Rhabdomyosarcomas With VGLL2 Rearrangement Are Not Always an Indolent Disease: A Study of 4 Aggressive Cases With Clinical, Pathologic, Molecular, and Radiologic Findings.

VGLL2-rearranged rhabdomyosarcomas (RMS) are rare low-grade tumors with only favorable outcomes reported to date. We describe 4 patients with VGLL2-rearranged RMS confirmed by molecular studies, who experienced local progression and distant metastases, including 2 with fatal outcomes. Tumors were diagnosed at birth (n=3) or at 12 months of age (n=1), and were all localized at initial diagnosis, but unresectable and therefore managed with chemotherapy and surveillance.

MR Imaging Features to Differentiate Retinoblastoma from Coats' Disease and Persistent Fetal Vasculature.

Retinoblastoma mimickers, or pseudoretinoblastoma, are conditions that show similarities with the pediatric cancer retinoblastoma. However, false-positive retinoblastoma diagnosis can cause mistreatment, while false-negative diagnosis can cause life-threatening treatment delay. The purpose of this study is to identify the MR imaging features that best differentiate between retinoblastoma and the most common pseudoretinoblastoma diagnoses: Coats' disease and persistent fetal vasculature (PFV).

[Diagnostic strategy in pediatrics soft tissue sarcomas].

Soft tissue sarcomas in children are rare tumor, representing around 6 to 7% of children cancer. They spread mostly sporadically (90%) and therefore are rarely associated to an underlying constitutional genetic disease (10%). About half of those sarcomas are rhabdomyosarcomas and the others are a very heterogenous histologic group with various bio-pathologies and prognosis.