Chromosomal rearrangements involving the FOXO1 gene (located at G-band region 13q14) are recurrent findings in cases of alveolar rhabdomyosarcoma. Two translocations, t(2;13)(q35;q14) and t(1;13)(p36;q14), juxtapose portions of the PAX3 or PAX7 gene (on chromosomes 2 or 1, respectively) with portions of the FOXO1 gene.

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

Specimens should be immersed in sterile culture medium, sterile Hanks Balance Salt Solution (HBSS) or sterile saline within one (1) hour of procedure

1. Fix the tissue in 10% formalin for 6 - 72 hours.
2. Prepare a Formalin-fixed, paraffin-embedded (FFPE) tissue block

Either the entire block, or two (2) 5 micron cuts mounted on positively charged slides and one (1) H&E stained slide can be submitted for testing

If the entire block is submitted, an H&E will be cut and stained, and assessed by an HPA pathologist.

FFPE tissue block or

Tissue section mounted on charged, unstained 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: >1.5% of 200 nuclei

Negative for rearrangement: ≤1.5% of 200 nuclei