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A subset of ectomesenchymal chondromyxoid tumours of the tongue show EWSR 1 rearrangements and are genetically linked to soft tissue myoepithelial neoplasms: a study of 11 cases
Author(s) -
Argyris Prokopios P,
Bilodeau Elizabeth A,
Yancoskie Aaron E,
Trochesset Denise,
Pambuccian Stefan E,
Wetzel Stephanie L,
Shah Sonal S,
Edelman Morris,
Freedman Paul,
Dolan Michelle,
Koutlas Ioannis G
Publication year - 2016
Publication title -
histopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.626
H-Index - 124
eISSN - 1365-2559
pISSN - 0309-0167
DOI - 10.1111/his.12973
Subject(s) - myoepithelial cell , myoepithelioma , fluorescence in situ hybridization , soft tissue , biology , tongue , pathology , gene rearrangement , atypia , soft palate , pleomorphic adenoma , anatomy , chromosome , salivary gland , immunohistochemistry , gene , medicine , genetics , surgery
Aims 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 ( EWSR 1 ) rearrangement is found in 45% of cutaneous, soft tissue and bone myoepithelial neoplasms, and pleomorphic adenoma gene 1 ( PLAG 1 ) aberrations are found in 37% of EWSR 1 ‐negative soft tissue myoepitheliomas. The aim of this study was to evaluate the presence of EWSR 1 and PLAG 1 rearrangements in ECT s. Methods and results Eleven formalin‐fixed, paraffin‐embedded ECT s were evaluated with fluorescence in‐situ hybridization probes for EWSR 1 (22q12) and PLAG 1 (8q12). Among the 11 ECT s tested, three (27.3%) showed EWSR 1 rearrangement in >15% of tumour cells, whereas eight (72.7%) cases did not show EWSR 1 rearrangement. Eight of nine (89%) ECT s showed gain of EWSR 1 , probably representing gain of all or part of chromosome 22, in a varying proportion of neoplastic cells ranging between 1.4% and 27.9%. PLAG 1 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 EWSR 1 rearrangement in >25% of ECT s. These results suggest that some ECT s are at least genetically related to myoepithelioma of the soft parts. Finally, PLAG 1 aberrations do not appear to be critical in the pathogenesis of ECT of the tongue.