Classification Of Pediatric Tumors Research Articles

Molecular and Pathological Features of Paediatric High-Grade Gliomas.

Paediatric high-grade gliomas are among the most common malignancies found in children. Despite morphological similarities to their adult counterparts, there are profound biological and molecular differences. Furthermore, and thanks to molecular biology, the diagnostic pathology of paediatric high-grade gliomas has experimented a dramatic shift towards molecular classification, with important prognostic implications, as is appropriately reflected in both the current WHO Classification of Tumours of the Central Nervous System and the WHO Classification of Paediatric Tumours. Emphasis is placed on histone 3, IDH1, and IDH2 alterations, and on Receptor of Tyrosine Kinase fusions. In this review we present the current diagnostic categories from the diagnostic pathology perspective including molecular features.

Interpretation on genetic tumour syndromes in the 5th WHO classification of paediatric tumours: part Ⅰ

Interpretation on genetic tumour syndromes in the 5th WHO classification of paediatric tumours: part Ⅰ

Interpretation of liver tumors in the 5th edition of the WHO classification of pediatric tumors

Interpretation of liver tumors in the 5th edition of the WHO classification of pediatric tumors

Interpretation of the 5th edition WHO classification of pediatric tumors

Interpretation of the 5th edition WHO classification of pediatric tumors

Pediatric hepatic vascular tumors: clinicopathologic characteristics of 33 cases and proposed updates to current classification schemes

Pediatric hepatic vascular tumors (HVTs) are rare neoplasms with features distinct from their cutaneous counterparts. Their behavior ranges from benign to malignant, with each subtype having therapeutic differences. Histopathologic descriptions of large cohorts are scarce in the literature. Thirty-three putative HVTs diagnosed from 1970 to 2021 were retrieved. All available clinical and pathologic materials were reviewed. Lesions were reclassified according to the World Health Organization (WHO) classification of pediatric tumors [1] ashepatic congenital hemangioma (HCH; n=13), hepatic infantile hemangioma (HIH; n=10), hepatic angiosarcoma (HA; n=3), and hepatic epithelioid hemangioendothelioma (HEH; n=1). Vascular malformations (n=5) or vascular-dominant mesenchymal hamartoma (n=1) were excluded. HCH frequently showed involutional changes, whereas HIH often had anastomosing channels and pseudopapillae formation. HA had solid areas with epithelioid and/or spindled endothelial morphology, significant atypia, increased mitoses, high proliferation index, and occasionally necrosis. On morphology analysis, a subset of HIH showed features worrisome for progression to HA including solid glomeruloidproliferation, increased mitoses, and epithelioid morphology. The widely metastatic and fatal HEH was observed in a 5-year-old male with multiple liver lesions. Immunohistochemically, HIHs and HA were Glucose transporter isoform 1 (GLUT-1) positive. One HIH patient died from postoperative complications, whereas 3 are alive without disease. Five HCH patients are alive and well. Two of three HA patients died of disease, and 1is alive without recurrence. To our knowledge, this is the largest series of pediatric HVTs reviewing clinicopathologic features based on current Pediatric WHO nomenclature [1]. We highlight diagnostic challenges and propose inclusion of an intermediate category between HIH and HA which warrants closer follow-up.

A Summary of the Inaugural WHO Classification of Pediatric Tumors: Transitioning from the Optical into the Molecular Era.

Pediatric tumors are uncommon, yet are the leading cause of cancer-related death in childhood. Tumor types, molecular characteristics, and pathogenesis are unique, often originating from a single genetic driver event. The specific diagnostic challenges of childhood tumors led to the development of the first World Health Organization (WHO) Classification of Pediatric Tumors. The classification is rooted in a multilayered approach, incorporating morphology, IHC, and molecular characteristics. The volume is organized according to organ sites and provides a single, state-of-the-art compendium of pediatric tumor types. A special emphasis was placed on "blastomas," which variably recapitulate the morphologic maturation of organs from which they originate. SIGNIFICANCE: In this review, we briefly summarize the main features and updates of each chapter of the inaugural WHO Classification of Pediatric Tumors, including its rapid transition from a mostly microscopic into a molecularly driven classification systematically taking recent discoveries in pediatric tumor genomics into account.

Abstract B48: Minimally invasive classification of pediatric solid tumors using reduced representation bisulfite sequencing of cell-free DNA

Abstract In the clinical management of pediatric solid tumors, histologic examination of tumor tissue obtained by an invasive biopsy remains the gold standard to establish a conclusive pathologic diagnosis. However, correct diagnosis in pediatric oncology can be challenging in some tumor types, especially in renal tumors or central nervous system tumors. The DNA methylation pattern of a tumor is known to correlate with the histopathologic diagnosis across cancer types and is showing promise in the diagnostic workup of tumor samples. It has previously been shown that this methylation pattern can be detected in the cell-free circulating DNA isolated from blood plasma of cancer patients. Here, we provide proof of concept of histopathologic classification of pediatric tumors using cell-free reduced representation bisulfite sequencing (cf-RRBS) from retrospectively collected plasma and cerebrospinal fluid samples. Using computational deconvolution of the DNA methylation profiles, we were able to obtain the correct tumor type in 49 out of 60 (81.6%) samples starting from minute amounts (less than 10 ng) of cell-free circulating DNA. We could demonstrate that the majority of misclassifications were associated with bad sample quality, evidenced by an increase of the test accuracy to 94.3% when only including good-quality samples. Misclassifications were not associated with the extent of the disease. Furthermore, we were able to derive the copy number profile or tumor subtype from the same assay. Our findings show the potential of the approach to tackle some of the remaining diagnostic challenges in pediatric oncology in a cost-effective and minimally invasive manner. Given the fact that primary tumor material might be difficult to obtain, in particular in critically ill children or depending on the tumor location, and might be limited in terms of quantity or quality, our assay could become complementary to the classical tissue biopsy in these difficult cases. A preprint of the study manuscript is already available at bioRxiv: https://doi.org/10.1101/795047. Citation Format: Ruben Van Paemel, Andries De Koker, Charlotte Vandeputte, Lieke Van Zogchel, Tim Lammens, Geneviève Laureys, Jo Vandesompele, Gudrun Schleiermacher, Matthieu Chicard, Nadine Van Roy, Ales Vicha, Godelieve A. M. Tytgat, Nico Callewaert, Bram De Wilde, Katleen De Preter. Minimally invasive classification of pediatric solid tumors using reduced representation bisulfite sequencing of cell-free DNA [abstract]. In: Proceedings of the AACR Special Conference on Advances in Liquid Biopsies; Jan 13-16, 2020; Miami, FL. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(11_Suppl):Abstract nr B48.