title: Small cell osteosarcoma with Ewing sarcoma breakpoint region 1 gene rearrangement detected by interphase fluorescence in situ hybridization.
abstract: Because of its characteristic morphologic appearance, small cell osteosarcoma (SCO) can be confused with other small round cell malignancies of the bone, most importantly with Ewing sarcoma, making this distinction difficult. A specific tool used in separating SCO from Ewing sarcoma has been the detection of Ewing sarcoma breakpoint region 1 (EWSR1) gene rearrangements in Ewing sarcoma and their absence in SCO. However, there are rare case reports that have documented the existence of EWSR1 gene rearrangement in SCO. In this report, we describe another case of SCO with an EWSR1 gene rearrangement detected by interphase fluorescence in situ hybridization. Our finding adds support to the existing evidence that SCO is a tumor that can be characterized by EWSR1 gene arrangements. Therefore, we caution the pathology community not to rely solely on molecular studies in distinguishing SCO from Ewing sarcoma.
authors.affiliation: Department of Pathology, VCU Health System, Richmond, VA 23298-0662, USA. edragoescu@mcvh-vcu.edu
authors.forename: Ema
authors.initials: E
authors.lastname: Dragoescu
authors.forename: Colleen
authors.initials: C
authors.lastname: Jackson-Cook
authors.forename: Gregory
authors.initials: G
authors.lastname: Domson
authors.forename: Davis
authors.initials: D
authors.lastname: Massey
authors.forename: William C
authors.initials: WC
authors.lastname: Foster
mesh_terms: D000293:Adolescent; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001706:Biopsy; D001859:Bone Neoplasms / Q000235:genetics* / Q000473:pathology; D002148:Calmodulin-Binding Proteins / Q000378:metabolism; D002892:Chromosomes, Human, Pair 22 / Q000235:genetics*; D015321:Gene Rearrangement; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007399:Interphase / Q000235:genetics; D008279:Magnetic Resonance Imaging; D008297:Male; D012516:Osteosarcoma / Q000235:genetics* / Q000473:pathology; D034802:RNA-Binding Protein EWS; D016601:RNA-Binding Proteins / Q000378:metabolism; D012512:Sarcoma, Ewing / Q000235:genetics* / Q000473:pathology; D018228:Sarcoma, Small Cell / Q000235:genetics* / Q000473:pathology; D014057:Tomography, X-Ray Computed; D014178:Translocation, Genetic
chemical_list: D014408:Biomarkers, Tumor; D002148:Calmodulin-Binding Proteins; C500986:EWSR1 protein, human; D034802:RNA-Binding Protein EWS; D016601:RNA-Binding Proteins