A group of sclerosing epithelioid fibrosarcomas with low-level amplified EWSR1-CREB3L1 fusion gene in children

Pathol Res Pract. 2022 Feb:230:153754. doi: 10.1016/j.prp.2021.153754. Epub 2021 Dec 30.

Abstract

Sclerosing epithelioid fibrosarcoma (SEF), typically arising in middle-aged and older adults, is a rare malignant fibroblastic neoplasm characterized by epithelioid fibroblasts embedded in sclerotic hyalinized stroma. This tumor frequently harbors translocation between EWSR1 and CREB3 subfamily members. Here, we describe four cases of SEF with unique genetic characteristics in children. All tumors were located in the deep soft tissue of the trunk and celom. Histopathologically, the tumors were featured by prominent hyalinized sclerotic collagenous stroma within which relatively bland and monomorphic epithelioid cells were arranged in cords, nests, or sheets. Low-grade fibromyxoid sarcoma-like zones varied among cases. MUC4 was strong and diffuse. CD99 was positive. Transmission electron microscopy demonstrated spindle or polyhedral neoplastic cells with a collagen fiber-rich stroma. Interphase fluorescence in situ hybridization (FISH) revealed local amplification of the EWSR1 locus. Whole-genome sequencing indicated translocation between EWSR1 and CREB3L1 together with low-level amplification of the fusion parts. RT-PCR and Sanger sequencing confirmed the fusion transcript. Single nucleotide polymorphism and FISH analyses demonstrated co-deletion of 11p and 22q. The consistent genetic features indicated the presence of a unique molecular variant of SEF. DATA AVAILABILITY STATEMENT: The data used to support the findings of this study are available from the corresponding author upon request.

Keywords: CREB3L1; EWSR1; Low-level amplification; Sclerosing epithelioid fibrosarcoma.

Publication types

  • Case Reports

MeSH terms

  • Biomarkers, Tumor / genetics*
  • Child
  • Child, Preschool
  • Cyclic AMP Response Element-Binding Protein / genetics*
  • Epithelioid Cells / ultrastructure
  • Female
  • Fibrosarcoma / genetics*
  • Fibrosarcoma / ultrastructure
  • Gene Amplification*
  • Gene Fusion*
  • Genetic Predisposition to Disease
  • Humans
  • In Situ Hybridization, Fluorescence
  • Male
  • Nerve Tissue Proteins / genetics*
  • Phenotype
  • RNA-Binding Protein EWS / genetics*
  • Sclerosis
  • Soft Tissue Neoplasms / genetics*
  • Soft Tissue Neoplasms / ultrastructure
  • Whole Genome Sequencing

Substances

  • Biomarkers, Tumor
  • CREB3L1 protein, human
  • Cyclic AMP Response Element-Binding Protein
  • EWSR1 protein, human
  • Nerve Tissue Proteins
  • RNA-Binding Protein EWS