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HelpTest ID DDITF Myxoid/Round Cell Liposarcoma, 12q13 (DDIT3 or CHOP) Rearrangement, FISH, Tissue
Useful For
Aiding in the diagnosis of myxoid/round cell liposarcoma by detecting a neoplastic clone associated with gene rearrangement involving the DDIT3 (CHOP) gene region at 12q13
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| _PBCT | Probe, +2 | No, (Bill Only) | No |
| _PADD | Probe, +1 | No, (Bill Only) | No |
| _PB02 | Probe, +2 | No, (Bill Only) | No |
| _PB03 | Probe, +3 | No, (Bill Only) | No |
| _IL25 | Interphases, <25 | No, (Bill Only) | No |
| _I099 | Interphases, 25-99 | No, (Bill Only) | No |
| _I300 | Interphases, ≥100 | No, (Bill Only) | No |
Testing Algorithm
This test does not include a pathology consult. If a pathology consultation is requested, 70012 / Pathology Consultation should be ordered and the appropriate FISH test will be ordered and performed at an additional charge.
This test includes a charge for application of the first probe set (2 FISH probes) and professional interpretation of results. Additional charges will be incurred for application of all reflex probes performed. Analysis charges will be incurred based on the number of cells analyzed per probe set. If no cells are available for analysis, no analysis charges will be incurred.
Method Name
Fluorescence In Situ Hybridization (FISH)
Reporting Name
DDIT3, Myxoid Liposarcoma, FISH, TsSpecimen Type
TissueForms: If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:
Oncology Test Request Form (T729) (http://www.mayomedicallaboratories.com/it-mmfiles/oncology-request-form.pdf)
Cardiovascular Test Request Form (T724) (http://www.mayomedicallaboratories.com/it-mmfiles/cardiovascular-request-form.pdf)
Provide a pathology report with each tissue specimen. The laboratory will not reject a specimen that arrives without this information but will hold the specimen until a pathology report is received.
Advise Express Mail or equivalent if not on courier service.
Submit only 1 of the following specimens:
Specimen Type: Tissue
Preferred: Tissue block
Collection Instructions: Submit a formalin-fixed, paraffin-embedded (FFPE) tumor tissue block. Blocks prepared with alternative fixation methods may be acceptable; provide fixation method used.
Acceptable: Slides
Collection Instructions: Four consecutive, unstained, 5 micron-thick sections placed on positively charged slides, and 1 hematoxylin and eosin-stained slide.
Specimen Minimum Volume
Two consecutive, unstained, 5 micron-thick sections placed on positively charged slides and 1 hematoxylin and eosin-stained slide
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Tissue | Ambient (preferred) | |
| Refrigerated | ||
Clinical Information
Myxoid/round cell liposarcoma is the second most common subtype of liposarcoma, accounting for more than one third of all liposarcomas and representing about 10% of all adult soft-tissue sarcomas. Myxoid/round cell liposarcoma is described as a malignant tumor composed of uniform round to oval shaped primitive nonlipogenic mesenchymal cells and a variable number of small signet-ring lipoblasts in a prominent myxoid stroma with a characteristic branching vascular pattern.
A unique chromosome translocation, t(12;16)(q13;p11), resulting in a fusion of the DDIT3 gene (also known as CHOP or GADD153) on chromosome 12 and the FUS gene (also referred to as TLS) on chromosome 16, is the key genetic aberration in myxoid/round cell liposarcoma. More than 90% of myxoid/round cell liposarcoma are cytogenetically characterized by this translocation. In rare cases, a variant t(12;22)(q13;q12) has been described in which DDIT3 (CHOP) fuses with EWS, a gene highly related to FUS.
Reference Values
An interpretive report will be provided.
Cautions
This test is not approved by the U.S. Food and Drug Administration and it is best used as an adjunct to existing clinical and pathologic information.
Fixatives other than formalin (eg, Prefer, Bouin's) may not be successful for FISH assays, however nonformalin-fixed samples will not be rejected.
Paraffin-embedded tissues that have been decalcified are generally unsuccessful for FISH analysis. The pathologist reviewing the hematoxylin and eosin-stained slide may find it necessary to cancel testing.
Day(s) Performed
Samples processed Monday through Sunday. Results reported Monday through Friday, 8 a.m.-5 p.m. CT.
Report Available
7 daysPerforming Laboratory
Mayo Medical Laboratories in Rochester
Test Classification
This test was developed using an analyte specific reagent. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.CPT Code Information
88271x2, 88291 – DNA probe, each (first probe set), Interpretation and report
88271x2 – DNA probe, each; each additional probe set (if appropriate)
88271x1 – DNA probe, each; coverage for sets containing 3 probes (if appropriate)
88271x2 – DNA probe, each; coverage for sets containing 4 probes (if appropriate)
88271x3 – DNA probe, each; coverage for sets containing 5 probes (if appropriate)
88274 w/modifier 52 – Interphase in situ hybridization, <25 cells, each probe set (if appropriate)
88274 – Interphase in situ hybridization, 25 to 99 cells, each probe set (if appropriate)
88275 – Interphase in situ hybridization, 100 to 300 cells, each probe set (if appropriate)