Rearrangement of the DDIT3 (CHOP) gene (CHOP) located at 12q13 is the cytogenetic hallmark of myxoid liposarcomas.  A t(12;16)(q13;p11) resulting in the fusion of the DDIT3 and FUS genes is present in more than 90% of myxoid and round cell liposarcomas. A variant t(12;22)(q13;q12) resulting in the fusion of the DDIT3 and EWSR1 genes has also been reported.

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

Place 5 mm³ tissue specimen in a sterile container filled with sterile culture medium, sterile Hanks Balance Salt Solution (HBSS) or sterile saline within one hour of procedure.

Sterile container filled with sterile culture medium, sterile Hanks Balance Salt Solution (HBSS) or sterile saline within one hour of procedure.

Formalin vial

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

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

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

• Cytogenetics oncology request

Ambient

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

Fluorescence in situ hybridization (FISH)

Positive for rearrangement:  >3.0% of 200 nuclei

Negative for rearrangement: ≤3.0% of 200 nuclei