The t(11;22)(q24;q12) involving the EWSR1 gene located at g-band region 22q12 is the cytogenetic hallmark of Ewing sarcoma.  EWSR1 rearrangements are present in 80-90% of these tumors.

Sterile vial/container filled with sterile culture medium, sterile Hanks Balance Salt Solution (HBSS) or sterile saline.

Collect a 5 mm³ sample of involved tissue (solid tumor or other) and place in sterile culture medium, sterile Hanks Balance Salt Solution (HBSS) or sterile saline within 1 hr of procedure

Sterile vial/container filled with sterile culture medium, sterile Hanks Balance Salt Solution (HBSS) or sterile saline.

Formalin vial

1. Fix the specimen in 10% neutral buffered formalin for 6 - 72 hours
2. Prepare a formalin-fixed, paraffin-embedded (FFPE) tumor block
3. Submit 2 unstained 5 micron cuts of involved tissue mounted on positively charged slides and 1 H & E

  or

Submit the formalin-fixed, paraffin-embedded (FFPE) tumor block.  An H & E   will be cut and stained, and assessed by an HPA  pathologist

Formalin-fixed, paraffin embedded (FFPE) block or 5 micron cuts mounted on positively charged slides

• Cytogenetics oncology requisition

Ambient

• Improper label (unlabeled or mislabeled)
• Wrong container (anticoagulant or solution)
• Improper storage
• Leaking container
• Slides broken beyond repair

Fluorescence in situ hybridization (FISH)

Positive for rearrangement:    >2.5% of 200 nuclei

Negative for rearrangement:  ≤2.5% of 200 nuclei