Histone H3 trimethylation on lysine 27 immunostaining pattern in -associated tumors.

Background: -associated tumors are heterogeneous and affect several organs. -associated primary intracranial sarcoma is associated with histone H3 trimethylation on lysine 27 (H3K27me3) loss in nucleus by immunohistochemistry.

Methods: We explored the H3K27me3 immunostaining pattern in other -associated tumors.

Embryonal sarcoma of the liver in pediatric and young adult patients: A report from Children's Oncology Group study ARST0332.

Background: Embryonal sarcoma of the liver (ESL) is a rare mesenchymal tumor most common in childhood; the optimal treatment approach is uncertain. The clinical features and outcomes of patients with ESL enrolled in a Children's Oncology Group (COG) clinical trial that evaluated a risk-based strategy for treating soft tissue sarcomas in patients aged <30 years were evaluated.

Methods: This subset analysis included patients with ESL enrolled in COG study ARST0332.

Pediatric Sertoli-Leydig Cell Tumors of the Ovary: An Integrated Study of Clinicopathological Features, Pan-cancer-Targeted Next-generation Sequencing and Chromosomal Microarray Analysis From a Single Institution.

Sertoli-Leydig cell tumors (SLCTs) are currently classified into 3 molecular subtypes: DICER1 -mutant (younger patient age), FOXL2 -mutant, and DICER1/FOXL2 -wildtype. However, it is not clear whether all pediatric SLCTs are DICER1 -mutant molecular subtypes and whether other molecular genetic aberrations besides DICER1 are involved in the pathogenesis and prognosis of these tumors. We studied comprehensive data for 8 cases of pediatric SLCTs, including clinicopathological features, pan-cancer-targeted next-generation sequencing/OncoKids panel, and chromosomal microarray analysis, to further analyze the correlation among clinicopathological features, molecular genetic aberrations, and prognosis.

FGFR1 gene fusions in a subset of pediatric mesenchymal tumors: Expanding the genetic spectrum of tumors sharing histologic overlap with infantile fibrosarcoma and "NTRK-rearranged" spindle cell neoplasms.

As the classification of kinase-driven spindle cell tumors continues to evolve, we describe the first series of pediatric mesenchymal tumors harboring FGFR1 gene fusions that share histologic overlap with infantile fibrosarcoma and "NTRK-rearranged" spindle cell neoplasms. Herein, we present three cases of FGFR1-rearranged pediatric mesenchymal tumors, including one case with FGFR1::PARD6B gene fusion and two cases with FGFR1::EBF2 gene fusion. The tumors involved infants ranging from 3 to 9 months in age with a male-to-female ratio of 2:1.

The Pathologic Diagnosis of Pediatric Soft Tissue Tumors in the Era of Molecular Medicine: The Sarcoma Pediatric Pathology Research Interest Group Perspective.

Context.—: Pediatric soft tissue tumors are one of the areas of pediatric pathology that frequently generate consult requests. Evolving classification systems, ancillary testing methods, new treatment options, research enrollment opportunities, and tissue archival processes create additional complexity in handling these unique specimens.

TP53 germline pathogenic variant frequency in anaplastic rhabdomyosarcoma: A Children's Oncology Group report.

Rhabdomyosarcoma (RMS) is a well-described cancer in Li-Fraumeni syndrome, resulting from germline TP53 pathogenic variants (PVs). RMS exhibiting anaplasia (anRMS) are associated with a high rate of germline TP53 PVs. This study provides updated estimates of the prevalence of TP53 germline PVs in RMS (3%) and anRMS (11%) from a large cohort (n = 239) enrolled in five Children's Oncology Group (COG) clinical trials.

Lymph node metastases in paediatric and young adult patients with non-rhabdomyosarcoma soft tissue sarcoma (NRSTS): Findings from Children's Oncology Group (COG) study ARST0332.

Purpose: The aim of this paper is to better define the clinical features and outcomes of young patients with non-rhabdomyosarcoma soft tissue sarcoma (NRSTS) with regional and distant lymph node (LN) metastases treated in a standardised fashion, we analysed LN involvement in COG study ARST0332, which evaluated a risk-based treatment strategy for young patients with all stages of NRSTS.

Patients And Methods: Patients <30 years old with newly diagnosed NRSTS and LN metastases enrolled on ARST0332 were studied. Regional LN sampling was required for those with epithelioid sarcoma, clear cell sarcoma or clinically/radiographically enlarged LNs.

Pediatric Sarcomas: The Next Generation of Molecular Studies.

Pediatric sarcomas constitute one of the largest groups of childhood cancers, following hematopoietic, neural, and renal lesions. Partly because of their diversity, they continue to offer challenges in diagnosis and treatment. In spite of the diagnostic, nosologic, and therapeutic gains made with genetic technology, newer means for investigation are needed.

An Integrative Morphologic and Molecular Approach for Diagnosis and Subclassification of Rhabdomyosarcoma.

Context.—: Rhabdomyosarcoma, the most common soft tissue sarcoma of children, is currently classified into the following 4 subtypes: embryonal rhabdomyosarcoma, alveolar rhabdomyosarcoma, spindle cell/sclerosing rhabdomyosarcoma, and pleomorphic rhabdomyosarcoma, based on recent molecular genetic knowledge and morphologic features.

Objective.

Rhabdomyosarcoma: How Advanced Molecular Methods Are Shaping the Diagnostic and Therapeutic Paradigm.

For the past 40 years, progress in rhabdomyosarcoma (RMS) has been focused on understanding its molecular basis and characterizing the mutations that drive its tumorigenesis and progression. Genetic predisposition to RMS has allowed discovery of key genetic pathways and driver mutations. Subclassification of RMS into embryonal (ERMS) and alveolar (ARMS) subtypes has shifted from histology to PAX-FOXO1 fusion status, and new driver mutations have been found in spindle cell RMS.

Epithelioid Sarcoma Arising in a Long-Term Survivor of an Atypical Teratoid/Rhabdoid Tumor in a Patient With Rhabdoid Tumor Predisposition Syndrome.

Rhabdoid tumor predisposition syndrome (RTPS) is defined as the presence of a or genetic aberration in a patient with malignant rhabdoid tumor. Patients with RTPS are more likely to present with synchronous or metachronous rhabdoid tumors. Based on the current state of rhabdoid tumor taxonomy, these diagnoses are based largely on patient demographics, anatomic location of disease, and immunohistochemistry, despite their nearly identical histologic and immunohistochemical profiles.

Rhabdomyosarcoma: From Obscurity to Clarity in Diagnosis … But With Ongoing Challenges in Management: The Farber-Landing Lecture of 2020.

Rhabdomyosarcoma, the most common soft tissue sarcoma in childhood, has challenged and intrigued soft tissue pathologists ever since the original descriptions. Once based on the identification of rhabdomyoblastic cells with elongate eosinophilic cytoplasm, the diagnosis has evolved to include tumors composed only of primitive mesenchymal cells but now relies heavily on immunohistochemical stains for desmin, myogenin, and MyoD. Rhabdomyosarcomas show a variety of histological patterns, giving rise to classifications that have included embryonal, alveolar, botryoid, pleomorphic, spindle cell, and sclerosing subtypes.

A History of Board Certification in Pediatric Pathology on Its 30th Anniversary.

In 1983 under the leadership of Dr. Daria Haust, the Pediatric Pathology Club (PPC; forerunner of the Society for Pediatric Pathology [SPP]), promulgated bylaws that included recognition of the special expertise required in pediatric pathology. This standard followed formal discussion that began as early as 1970, suggesting that special certification should be pursued, and the idea was vetted by the PPC in 1980 following a special report by Dr.

The prognostic significance of anaplasia in childhood rhabdomyosarcoma: A report from the Children's Oncology Group.

Background: Established prognostic indicators in rhabdomyosarcoma (RMS), the most common childhood soft tissue sarcoma, include several clinicopathologic features. Among pathologic features, anaplasia has been suggested as a potential prognostic indicator, but the clinical significance of anaplasia remains unclear.

Methods: Patients enrolled on one of five recent Children's Oncology Group clinical trials for RMS (D9602, n = 357; D9802, n = 80; D9803, n = 462; ARST0331, n = 335; and ARST0531, n = 414) with prospective central pathology review were included in this study.

Alveolar rhabdomyosarcoma with regional nodal involvement: Results of a combined analysis from two cooperative groups.

Background: Treatment of children and adolescents with alveolar rhabdomyosarcoma (ARMS) and regional nodal involvement (N1) have been approached differently by North American and European cooperative groups. In order to define a better therapeutic strategy, we analyzed two studies conducted between 2005 and 2016 by the European paediatric Soft tissue sarcoma Study Group (EpSSG) and Children's Oncology Group (COG).

Methods: We retrospectively identified patients with ARMS N1 enrolled in either EpSSG RMS2005 or in COG ARST0531.

Clinicopathologic Characteristics of Late Acute Antibody-mediated Rejection in Pediatric Liver Transplantation.

Background: An early and accurate diagnosis of liver antibody-mediated rejection (AMR) followed by timely intervention is important for clinical management but remains challenging. The aim of this study was to assess the clinicopathologic characteristics and outcomes of late acute AMR in pediatric liver transplantation recipients.

Methods: We performed a retrospective review of 739 ABO-identical/compatible allograft liver biopsies from 199 pediatric transplantation recipients.

Histopathologic features of alveolar capillary dysplasia with misalignment of pulmonary veins with atypical clinical presentation.

Alveolar capillary dysplasia with misalignment of pulmonary veins (ACD/MPV) is a rare neonatal lung disease with fatal outcome. Typically, respiratory symptoms present in the first 24 hours of life and patients die within the neonatal period. Atypical, delayed clinical presentations and/or longer survival have also been reported.

Transcriptome analysis of desmoplastic small round cell tumors identifies actionable therapeutic targets: a report from the Children's Oncology Group.

To further understand the molecular pathogenesis of desmoplastic small round cell tumor (DSRCT), a fatal malignancy occurring primarily in adolescent/young adult males, we used next-generation RNA sequencing to investigate the gene expression profiles intrinsic to this disease. RNA from DSRCT specimens obtained from the Children's Oncology Group was sequenced using the Illumina HiSeq 2000 system and subjected to bioinformatic analyses. Validation and functional studies included WT1 ChIP-seq, EWS-WT1 knockdown using JN-DSRCT-1 cells and immunohistochemistry.

The Relevance of and Surgical Approach to the Suprahyoid Region in Thyroglossal Duct Surgery.

Objectives: Persistent or recurrent disease following excision of a thyroglossal duct cyst/sinus (TGDC) is often found in the suprahyoid region. Cadaver dissections were performed to identify and name important surgical landmarks in the suprahyoid area; a histopathologic analysis of surgical specimens was completed to determine the incidence and extent of microscopic disease; and clinical outcomes were compared to determine the efficacy of a specific anatomic dissection.

Study Design: Retrospective case series.

A risk-based treatment strategy for non-rhabdomyosarcoma soft-tissue sarcomas in patients younger than 30 years (ARST0332): a Children's Oncology Group prospective study.

Background: Tumour grade, tumour size, resection potential, and extent of disease affect outcome in paediatric non-rhabdomyosarcoma soft-tissue sarcoma (NRSTS), but no risk stratification systems exist and the standard of care is poorly defined. We developed a risk stratification system from known prognostic factors and assessed it in the context of risk-adapted therapy for young patients with NRSTS.

Methods: In this prospective study, eligible patients enrolled in 159 hospitals in three countries were younger than 30 years, had a Lansky (patients ≤16 years) or Karnofsky (patients >16 years) performance status score of at least 50, and a new diagnosis of a WHO (2002 criteria) intermediate (rarely metastasising) or malignant soft-tissue tumour (apart from tumour types eligible for other Children's Oncology Group studies and tumours for which the therapy in this trial was deemed inappropriate), malignant peripheral nerve sheath tumour, non-metastatic and grossly resected dermatofibrosarcoma protuberans, undifferentiated embryonal sarcoma of the liver, or unclassified malignant soft-tissue sarcoma.

Expanding the spectrum of dicer1-associated sarcomas.

DICER1 syndrome is a hereditary cancer predisposition syndrome caused by deleterious germline DICER1 mutations. Characteristic "hotspot" somatic mutations of DICER1 have been identified in DICER1-associated tumors. With the exception of genitourinary embryonal rhabdomyosarcoma and anaplastic sarcoma of the kidney, sarcomas are rarely reported in DICER1 syndrome.

Infantile Epithelioid Sarcoma with Genomic Segmental Amplification of as Double Minutes Plus Trisomy 2: A Case Report.

Epithelioid sarcoma is a malignant mesenchymal tumor exhibiting epithelioid cytomorphology and epithelial phenotype. Its histogenesis is unknown, but its tumorigenesis may relate to inactivation of tumor suppressor gene. This tumor typically affects young adults and older children, but it is uncommon in infants.

Risk-based treatment for patients with first relapse or progression of rhabdomyosarcoma: A report from the Children's Oncology Group.

Background: The purpose of this study was to evaluate risk and response-based multi-agent therapy for patients with rhabdomyosarcoma (RMS) at first relapse.

Methods: Patients with RMS and measurable disease at first relapse with unfavorable-risk (UR) features were randomized to a 6-week phase 2 window with 1 of 2 treatment schedules of irinotecan with vincristine (VI) (previously reported). Those with at least a partial response to VI continued to receive 44 weeks of multi-agent chemotherapy including the assigned VI regimen.

Clinical features and outcomes of young patients with epithelioid sarcoma: an analysis from the Children's Oncology Group and the European paediatric soft tissue Sarcoma Study Group prospective clinical trials.

Background: Data on the clinical features, optimal treatment and outcomes of paediatric patients with epithelioid sarcoma (ES) are limited and mostly retrospective.

Methods: A subset analysis of ES patients < 30 years of age enrolled on two international prospective clinical trials conducted between 7/2005 and 11/2015 was performed. Risk-adapted therapy was based on tumour diameter, histologic grade, extent of surgery and presence/absence of metastases and included surgery ± radiotherapy for all patients with the addition of ifosfamide/doxorubicin chemotherapy for intermediate-/high-risk patients.