Sclerosing Epithelioid Fibrosarcoma of the Bone With Rare EWSR1-CREB3L3 Translocation Driving Upregulation of the PI3K/mTOR Signaling Pathway. (December 2019)

• Record Type: Journal Article
• Authors: Shenoy, Archana; Surrey, Lea; Jain, Payal; Foster, Jessica; Straka, Joshua; Resnick, Adam; Waanders, Angela; Luo, Minjie; Li, Marilyn; Kazahaya, Ken; Bagatell, Rochelle; Wojcik, John; Pogoriler, Jennifer
• Is Part Of: Pediatric and developmental pathology. Volume 22:Number 6(2019)
• Page Start: 594
• Page End: 598
• Publication Date: 2019-12
• Subjects: EWSR1 translocation -- sclerosing epithelioid fibrosarcoma -- Ewing sarcoma -- bone tumors -- sarcoma -- molecular oncology; Pediatric pathology -- Periodicals; Children -- Diseases -- Periodicals; Diagnosis, Laboratory -- Periodicals; Abnormalities, Human -- Periodicals; Child development -- Periodicals; Pediatrics -- Periodicals; 616.07
• DOI: 10.1177/1093526619864230
• Languages: English
• ISSNs: 1093-5266

Abstract

Sclerosing epithelioid fibrosarcoma (SEF) is an uncommon neoplasm that rarely presents in bone. It is characterized by epithelioid cells arranged in nests and single-file cords within a sclerotic stromal background which may mimic neoplastic bone. SEF harbors an EWSR1 translocation, which may complicate its distinction from Ewing sarcoma in cases with histomorphologic overlap. We present a diagnostically challenging case of SEF in the mandible of a 16-year-old girl. Our experience highlights the lack of specificity of traditional morphology and EWSR1 break-apart fluorescent in situ hybridization. Open-ended RNA-based fusion gene testing coupled with MUC4 immunohistochemistry aided the eventual diagnosis in this case. Herein, we report the third case of SEF with EWSR1-CREB3L3 translocation and show that this fusion leads to aberrant upregulation of the phosphoinositide 3-kinase/mammalian target of rapamycin signaling pathway in heterologous cell models.