A practical approach to the clinical diagnosis of Ewing's sarcoma/primitive neuroectodermal tumour and other small round cell tumours sharing EWS rearrangement using new fluorescence in situ hybridisation probes for EWSR1 on formalin fixed, paraffin wax embedded tissue.
BACKGROUND
Over 90% of Ewing's sarcoma/primitive neuroectodermal tumour (ES/PNET) cases have the t(11;22) chromosomal rearrangement, which is also found in other small round cell tumours, including desmoplastic small round cell tumour (DSRCT) and clear cell sarcoma (CCS). Although this rearrangement can be analysed by fluorescence in situ hybridisation (FISH) using routinely formalin fixed, paraffin wax embedded (FFPE) tissues when fresh or frozen tissues are not available, a sensitive and convenient detection method is needed for routine clinical diagnosis.


OBJECTIVE
To investigate the usefulness of newly developed probes for detecting EWS rearrangement resulting from chromosomal translocations using FISH and FFPE tissue in the clinical diagnosis of ES/PNET, DSRCT, and CCS.


METHODS
Sixteen ES/PNETs, six DSRCTs, and six CCSs were studied. Three poorly differentiated synovial sarcomas, three alveolar rhabdomyosarcomas, and three neuroblastomas served as negative controls. Interphase FISH analysis was performed on FFPE tissue sections with a commercially available EWSR1 (22q12) dual colour, breakapart rearrangement probe.


RESULTS
One fused signal and one split signal of orange and green, demonstrating rearrangement of the EWS gene, was detected in 14 of 16 ES/PNETs, all six DRSCTs, and five of six CCSs, but not in the negative controls.


CONCLUSIONS
Interphase FISH using this newly developed probe is sensitive and specific for detecting the EWS gene on FFPE tissues and is of value in the routine clinical diagnosis of ES/PNET, DSRCT, and CCS.
Yamaguchi
U
U
Division of Orthopaedic Oncology, National Cancer Centre Hospital and Research Institute, Tokyo 104-0045, Japan.
Hasegawa
T
T
Morimoto
Y
Y
Tateishi
U
U
Endo
M
M
Nakatani
F
F
Kawai
A
A
Chuman
H
H
Beppu
Y
Y
Endo
M
M
Kurotaki
H
H
Furuta
K
K
D000293:Adolescent; D000328:Adult; D000368:Aged; D001859:Bone Neoplasms / Q000175:diagnosis* / Q000235:genetics; D002148:Calmodulin-Binding Proteins / Q000235:genetics*; D002648:Child; D002880:Chromosomes, Human, Pair 11 / Q000235:genetics; D002892:Chromosomes, Human, Pair 22 / Q000235:genetics; D015342:DNA Probes; D005260:Female; D005557:Formaldehyde; D015321:Gene Rearrangement; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000235:genetics; D018241:Neuroectodermal Tumors, Primitive, Peripheral / Q000175:diagnosis* / Q000235:genetics; D016612:Paraffin Embedding; D034802:RNA-Binding Protein EWS; D016601:RNA-Binding Proteins / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D018227:Sarcoma, Clear Cell / Q000175:diagnosis / Q000235:genetics; D012512:Sarcoma, Ewing / Q000175:diagnosis* / Q000235:genetics; D014178:Translocation, Genetic
D002148:Calmodulin-Binding Proteins; D015342:DNA Probes; C500986:EWSR1 protein, human; D009363:Neoplasm Proteins; D034802:RNA-Binding Protein EWS; D016601:RNA-Binding Proteins; D005557:Formaldehyde