Ewing sarcoma of bone shares a chromosomal translocation with peripheral PNET. Which translocation and resultant fusion oncogene drives this tumour?
- A t(2;13) producing PAX3-FOXO1 fusion
- B t(12;16) producing FUS-DDIT3 fusion
- C t(11;22)(q24;q12) producing EWS-FLI1 fusion ✓
- D t(X;18) producing SS18-SSX fusion
Correct answer: C. t(11;22)(q24;q12) producing EWS-FLI1 fusion
Explanation
Ewing sarcoma and peripheral PNET both belong to the Ewing family of tumours and harbour the translocation t(11;22)(q24;q12) in 85% of cases, producing the EWS-FLI1 oncogenic fusion transcript that drives transcriptional dysregulation and malignant transformation. The remaining cases have variants such as EWS-ERG [t(21;22)]. PAX3-FOXO1 is seen in alveolar rhabdomyosarcoma; FUS-DDIT3 in myxoid liposarcoma; SS18-SSX in synovial sarcoma. This molecular marker is diagnostically valuable when histology is equivocal.
Reference: Maheshwari Essential Orthopaedics, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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