DETECTION OF CHIMERIC TRANSCRIPTS IN DESMOPLASTIC SMALL ROUND-CELL TUMOR AND RELATED DEVELOPMENTAL TUMORS BY REVERSE-TRANSCRIPTASE POLYMERASE CHAIN-REACTION - A SPECIFIC DIAGNOSTIC ASSAY
E. Dealava et al., DETECTION OF CHIMERIC TRANSCRIPTS IN DESMOPLASTIC SMALL ROUND-CELL TUMOR AND RELATED DEVELOPMENTAL TUMORS BY REVERSE-TRANSCRIPTASE POLYMERASE CHAIN-REACTION - A SPECIFIC DIAGNOSTIC ASSAY, The American journal of pathology, 147(6), 1995, pp. 1584-1591
Desmoplastic small round cell tumor is a recently described entity ass
ociated with fusion of the EWS and WT1 genes and with expression of a
chimeric transcript. To investigate the structure and potential diagno
stic utility of the detection of EWS-WT1 chimeric RNA in desmoplastic
small round cell tumor, 12 examples of this entity and 49 other tumors
that enter in its differential diagnosis were studied by reverse tran
scriptase polymerase chain reaction for the presence of EWS-WT1, EWS-F
LI-1, PAX3-FKHR, and PAX7-FKHR chimeric transcripts. EWS-WT1 was detec
ted in 11 of 12 desmoplastic small round cell tumors but not in any ot
her tumor type studied, including 17 Wilms' tumors, 10 Ewing's sarcoma
s/primitive neuroectodermal tumors, 13 alveolar rhabdomyosarcomas, and
9 embryonal rhabdomyosarcomas. One desmoplastic small round cell tumo
r was found to have a variant EWS-WT1 chimeric product that included e
xon 8 of EWS. EWS-FLI-1 chimeric RNA was present in all Ewing's sarcom
a/primitive neuroectodermal tumor and not identified in any other tumo
r types, including desmoplastic small round cell tumor. PAX3/PAX7-FKHR
chimeras were present in 9 of 13 alveolar rhabdomyosarcomas but not i
n any other tumors. Detection of chimeric transcripts by reverse trans
criptase polymerase chain reaction is a very specific aid in different
ial diagnosis of developmental tumors and further establishes desmopla
stic small round cell tumor as a distinct entity.