title: Small round cell tumor with biphenotypic differentiation and variant of t(21;22)(q22;q12).
abstract: A 14-year-old boy presented with a soft tissue swelling on the outer aspect of his left upper arm. Examination of the tumor by light microscopy showed a small round cell tumor with a rare focus of myogenic differentiation. Myogenic differentiation was confirmed on ultrastructural examination by immunohistochemistry and reverse transcriptase polymerase chain reaction (RT-PCR). Conventional G-banding and fluorescent in situ hybridization (FISH) demonstrated a complex variant of t(21;22)(q22;q12). By RT-PCR, the EWS-ERG fusion transcript was defined as type 9e. This tumor was unusual in that it showed characteristics of myogenic and neural differentiation, and contained a rearrangement of the EWS gene consistent with a diagnosis of Ewing's sarcoma. This supports the hypothesis that a class of biphenotypic childhood sarcomas, with features of myogenic and neural differentiation, exists that may be related to the Ewing's sarcoma family of tumors.
authors.affiliation: Department of Pathology, Cytogenetics and Oncology, Children's Hospital, Western Bank, Sheffield, S10 2TH, UK.
authors.forename: S Y
authors.initials: SY
authors.lastname: Tan
authors.forename: S
authors.initials: S
authors.lastname: Burchill
authors.forename: S C
authors.initials: SC
authors.lastname: Brownhill
authors.forename: M P
authors.initials: MP
authors.lastname: Gerrard
authors.forename: A
authors.initials: A
authors.lastname: Watmore
authors.forename: B E
authors.initials: BE
authors.lastname: Wagner
authors.forename: S
authors.initials: S
authors.lastname: Variend
mesh_terms: D000293:Adolescent; D001859:Bone Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D002471:Cell Transformation, Neoplastic; D002871:Chromosome Banding; D002891:Chromosomes, Human, Pair 21; D002892:Chromosomes, Human, Pair 22; D004273:DNA, Neoplasm / Q000032:analysis; D003937:Diagnosis, Differential; D004210:Dissection; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008846:Micromanipulation; D010641:Phenotype; D034802:RNA-Binding Protein EWS; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012261:Ribonucleoproteins / Q000378:metabolism; D012512:Sarcoma, Ewing / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D018228:Sarcoma, Small Cell / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D014178:Translocation, Genetic / Q000235:genetics*
chemical_list: D004273:DNA, Neoplasm; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D034802:RNA-Binding Protein EWS; D012261:Ribonucleoproteins