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Ewing sarcoma

Friday 21 May 2004

Ewing tumor, Ewing tumour


- Ewing’s sarcoma

Digital cases (Digital slides)

- HPC:31 : Ewing sarcoma
- HPC:132 : Ewing sarcoma
- HPC:182 : Ewing sarcoma
- HPC:376 : EWSR1-FLI1+ bone-forming Ewing sarcoma (EWSR1-FLI1+ small cell osteosarcoma)


- epithelioid Ewing sarcoma
- spindle cell Ewing sarcoma
- atypical pleomorphic extraosseous Ewing sarcoma
- large cell Ewing sarcoma
- neuro-differentiated Ewing sarcoma (pPNET, peripheral primitive neuroectodermal tumor)
- bone-forming Ewing sarcoma (small cell osteosarcoma)


- skeletal Ewing sarcoma (osseous Ewing sarcoma)
- extraskeletal Ewing sarcoma (extraosseous Ewing sarcoma)

  • renal Ewing sarcoma


- CD99+ (MIC2+)
- FLI1+


- post-chemotherapy neuroblastoma-like differentiation in pPNET (16944972)
- Ewing sarcoma with osteoid formation (15188147)

Cytogenetics and molecular biology

Ewing family tumors are molecularly characterized by expression of chimeric transcripts generated by specific chromosomal translocations, most commonly involving fusion of the EWS gene to a member of the ETS family of transcription factors (including FLI1, ERG, ETV1, E1AF, and FEV).

Approximately 85% of reported cases of Ewing sarcoma bear an EWS-FLI1 fusion.

In rare cases, FUS can substitute for EWS, with translocation t(16;21)(p11;q24) producing a FUS-ERG fusion with no EWS rearrangement.

- EWSR1 rarrangements

  • t(11;22)(q24;q12) (EWSR1/FLI1 fusion gene) (85%) (11q24 and 22q12)
  • t(21;22)(q22;q12) (EWSR1/ERG fusion gene) (21q22 and 22q12)
  • t(2;22)(q36; q12) (EWSR1/FEV fusion gene) (2q36 and 22q12)
  • t(17;22)(q21;q12) (EWSR1/ETV4 fusion gene) (17q21 and 22q12)

- FUS rearrangements

Chromosomal imbalance (CGH)

Gains 1q+ 8+ 12+

See also

- Ewing sarcoma/primitive neuroectodermal tumor (ES/PNET)or "Ewing family of tumors" (EFTs)