Alternative Name
CHOP
Methodology
FISH
Test Description
Probes: DDIT3 (CHOP) (12q13)
Disease(s): Myxoid-round cell liposarcoma (M/RCLS)
Clinical Significance
The DDIT3 break-apart FISH test detects 12q13 rearrangements in myxoid-round cell liposarcoma (M/RCLS). The DDIT3 locus was formerly named CHOP. Fusion of DDIT3 and FUS genes in t(12;16)(q13;p11) is detected in >95% of cases. Occasionally observed is t(12;22)(q13;q12) in which DDIT3 and EWSR1 are fused. DDIT3 rearrangement partners will not be identified by this FISH test. For that purpose, please see the NGS Sarcoma Fusion Profile.
Specimen Requirements
  • Bone marrow aspirate:  N/A
  • Peripheral blood: N/A
  • Fresh, unfixed tissue: N/A.
  • Fluids: N/A
  • Paraffin block: Send paraffin block. Also send circled H&E slide for tech-only (required).
  • Cut slides: H&E slide (required) plus 4 unstained slides cut at 4-5 microns. Circle H&E slide for tech-only
Storage and Transportation
Refrigerate specimen. Do not freeze. Use cold pack for transport, making sure cold pack is not in direct contact with specimen.
CPT Code(s)*
88377x1 manual or 88374x1 automated
Turnaround Time
4 days
Level of Service
Global
Technical

*The CPT codes provided with our test descriptions are based on AMA guidelines and are for informational purposes only. Correct CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed.