title: A subset of ectomesenchymal chondromyxoid tumours of the tongue show EWSR1 rearrangements and are genetically linked to soft tissue myoepithelial neoplasms: a study of 11 cases.
abstract: OBJECTIVE
  Ectomesenchymal chondromyxoid tumour (ECT) is a rare, benign intraoral neoplasm showing a predilection for the anterior dorsum of the tongue. The World Health Organization includes ECT in the pathological spectrum of soft tissue myoepithelioma. EWS RNA-binding protein 1 gene (EWSR1) rearrangement is found in 45% of cutaneous, soft tissue and bone myoepithelial neoplasms, and pleomorphic adenoma gene 1 (PLAG1) aberrations are found in 37% of EWSR1-negative soft tissue myoepitheliomas. The aim of this study was to evaluate the presence of EWSR1 and PLAG1 rearrangements in ECTs.
  
  
  RESULTS
  Eleven formalin-fixed, paraffin-embedded ECTs were evaluated with fluorescence in-situ hybridization probes for EWSR1 (22q12) and PLAG1 (8q12). Among the 11 ECTs tested, three (27.3%) showed EWSR1 rearrangement in >15% of tumour cells, whereas eight (72.7%) cases did not show EWSR1 rearrangement. Eight of nine (89%) ECTs showed gain of EWSR1, probably representing gain of all or part of chromosome 22, in a varying proportion of neoplastic cells ranging between 1.4% and 27.9%. PLAG1 rearrangement was not detected in the successfully hybridized tissue sections (7/11). No correlation was observed between the molecular and histopathological findings, such as morphology of the neoplastic cells, the presence of atypia, and matrical type.
  
  
  CONCLUSIONS
  We identified EWSR1 rearrangement in >25% of ECTs. These results suggest that some ECTs are at least genetically related to myoepithelioma of the soft parts. Finally, PLAG1 aberrations do not appear to be critical in the pathogenesis of ECT of the tongue.
authors.affiliation: Division of Oral and Maxillofacial Pathology, School of Dentistry, University of Minnesota, Minneapolis, MN, USA.
authors.forename: Prokopios P
authors.initials: PP
authors.lastname: Argyris
authors.affiliation: Department of Diagnostic Sciences, University of Pittsburgh School of Dental Medicine, Pittsburgh, PA, USA.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Bilodeau
authors.affiliation: Touro College of Dental Medicine at New York Medical College, Valhalla, NY, USA.
authors.forename: Aaron E
authors.initials: AE
authors.lastname: Yancoskie
authors.affiliation: Department of Oral Biology and Pathology, Stony Brook University School of Dental Medicine, Stony Brook, NY, USA.
authors.forename: Denise
authors.initials: D
authors.lastname: Trochesset
authors.affiliation: Department of Pathology, Loyola University Medical Center, Maywood, IL, USA.
authors.forename: Stefan E
authors.initials: SE
authors.lastname: Pambuccian
authors.affiliation: Division of Oral and Maxillofacial Pathology, School of Dentistry, University of Minnesota, Minneapolis, MN, USA.
authors.forename: Stephanie L
authors.initials: SL
authors.lastname: Wetzel
authors.affiliation: Department of Oral and Maxillofacial Pathology, Radiology and Medicine, New York University College of Dentistry-New York, NY, USA.
authors.forename: Sonal S
authors.initials: SS
authors.lastname: Shah
authors.affiliation: Department of Pathology, Hofstra North Shore-LIJ School of Medicine-New Hyde Park, NY, USA.
authors.forename: Morris
authors.initials: M
authors.lastname: Edelman
authors.affiliation: Section of Oral Pathology, New York Presbyterian/Queens, Flushing, NY, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Freedman
authors.affiliation: Department of Laboratory Medicine and Pathology, University of Minnesota Medical School, University of Minnesota, Minneapolis, MN, USA.
authors.forename: Michelle
authors.initials: M
authors.lastname: Dolan
authors.affiliation: Division of Oral and Maxillofacial Pathology, School of Dentistry, University of Minnesota, Minneapolis, MN, USA. koutl001@umn.edu.
authors.forename: Ioannis G
authors.initials: IG
authors.lastname: Koutlas
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000235:genetics; D002148:Calmodulin-Binding Proteins / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics; D005260:Female; D015321:Gene Rearrangement; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008875:Middle Aged; D009208:Myoepithelioma / Q000235:genetics* / Q000473:pathology*; D034802:RNA-Binding Protein EWS; D016601:RNA-Binding Proteins / Q000235:genetics*; D012983:Soft Tissue Neoplasms / Q000235:genetics / Q000473:pathology; D014062:Tongue Neoplasms / Q000235:genetics* / Q000473:pathology*; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D002148:Calmodulin-Binding Proteins; D004268:DNA-Binding Proteins; C500986:EWSR1 protein, human; C104382:PLAG1 protein, human; D034802:RNA-Binding Protein EWS; D016601:RNA-Binding Proteins
keywords: EWSR1 rearrangement; PLAG1 rearrangement; ectomesenchymal chondromyxoid tumour; myoepithelial neoplasm; soft tissue myoepithelioma