On fluorescence in situ hybridization (FISH), a soft tissue tumor shows SS18-SSX fusion gene resulting from t(X;18)(p11;q11). This translocation is diagnostic of which neoplasm?
- A Synovial sarcoma ✓
- B Alveolar rhabdomyosarcoma
- C Ewing sarcoma
- D Clear cell sarcoma
Correct answer: A. Synovial sarcoma
Explanation
The SS18-SSX (formerly SYT-SSX) fusion gene resulting from t(X;18) translocation is the hallmark of synovial sarcoma, occurring in virtually all cases. Alveolar rhabdomyosarcoma has PAX3/7-FOXO1 fusions. Ewing sarcoma harbors EWSR1-FLI1 or EWSR1-ERG fusions. Clear cell sarcoma of soft tissue shows EWSR1-ATF1 fusion.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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