title: Adamantinoma-like Ewing's sarcoma: genomic confirmation, phenotypic drift.
abstract: Ewing's sarcoma, a highly malignant neoplasm, is characterized by an 11;22 translocation [t(11;22) (q24;q12)], resulting in the fusion of genes FLII and EWS. Adamantinoma of extragnathic bones, a low-grade malignant neoplasm with epithelial features, is not typically considered in the differential diagnosis of Ewing's sarcoma. In this study, three osseous Ewing's sarcomas with histological, immunohistochemical, or ultrastructural epithelial features were subjected to reverse transcription-polymerase chain reaction and sequencing studies for the Ewing's sarcoma molecular rearrangement. (Two of the three cases were originally described as adamantinomas or nontypical Ewing's sarcoma before the availability of genetic characterization.) In addition, traditional cytogenetic analysis and a unique combined interphase molecular cytogenetic/ immunocytochemical approach with bicolor 11;22 translocation breakpoint flanking probes (cosmids) and pancytokeratin antibodies were performed on one neoplasm. At(11;22) (q24;q12) was found in one neoplasm and a type II EWS/FLI-1 fusion transcript was detected in all three neoplasms. The combined genetic/immunocytochemical approach revealed the presence of the 11 ;22 translocation in the nuclei of cytokeratin immunoreactive cells. These genotypic and phenotypic findings delineate a novel Ewing's sarcoma histologic variant, "adamantinoma-like Ewing's sarcoma."
authors.affiliation: Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha 68198-5440, USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Bridge
authors.forename: M E
authors.initials: ME
authors.lastname: Fidler
authors.forename: J R
authors.initials: JR
authors.lastname: Neff
authors.forename: J
authors.initials: J
authors.lastname: Degenhardt
authors.forename: M
authors.initials: M
authors.lastname: Wang
authors.forename: C
authors.initials: C
authors.lastname: Walker
authors.forename: H D
authors.initials: HD
authors.lastname: Dorfman
authors.forename: K S
authors.initials: KS
authors.lastname: Baker
authors.forename: T A
authors.initials: TA
authors.lastname: Seemayer
mesh_terms: D000293:Adolescent; D001859:Bone Neoplasms / Q000000981:diagnostic imaging / Q000235:genetics* / Q000473:pathology; D003582:Cytogenetics; D003896:Desmosomes / Q000648:ultrastructure; D003937:Diagnosis, Differential; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007382:Intermediate Filaments / Q000648:ultrastructure; D007633:Keratins / Q000235:genetics; D008297:Male; D009375:Neoplasms, Glandular and Epithelial / Q000000981:diagnostic imaging / Q000235:genetics* / Q000473:pathology; D015514:Oncogene Proteins, Fusion / Q000235:genetics; D051789:Proto-Oncogene Protein c-fli-1; D012334:RNA, Neoplasm / Q000032:analysis; D034802:RNA-Binding Protein EWS; D011859:Radiography; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012512:Sarcoma, Ewing / Q000000981:diagnostic imaging / Q000235:genetics* / Q000473:pathology; D014157:Transcription Factors / Q000235:genetics