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HelpTest Code EWSF Ewing Sarcoma, 22q12 (EWSR1) Rearrangement, FISH, Tissue
Useful For
Detection of EWSR1 rearrangements irrespective of the EWSR1 fusion partner gene
Supporting the diagnosis of many neoplasms including, but not limited to, Ewing sarcoma, extraskeletal myxoid chondrosarcoma, desmoplastic small round cell tumor, clear cell sarcoma, and myxoid liposarcoma when used in conjunction with pathologic assessment
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 includes a charge for the probe application, analysis, and professional interpretation of results for one probe set (2 individual fluorescence in situ hybridization probes). No analysis charges will be incurred if an insufficient number of representative cells are available for analysis.
Appropriate ancillary probes may be performed at consultant discretion to render comprehensive assessment. Any additional probes will have the results included within the final report and will be performed at an additional charge.
Method Name
Fluorescence In Situ Hybridization (FISH)
Reporting Name
EWSR1 (22q12), FISH, TsSpecimen Type
TissueOrdering Guidance
This test does not include a pathology consultation. If a pathology consultation is requested, order PATHC / Pathology Consultation, and appropriate testing will be added at the discretion of the pathologist and performed at an additional charge.
Multiple oncology (cancer) gene panels are also available. For more information see Hematology, Oncology, and Hereditary Test Selection Guide
Additional Testing Requirements
Confirmation testing by next generation sequencing to resolve atypical or unbalanced fluorescence in situ hybridization results of this gene region is available, order SARCP / Sarcoma Targeted Gene Fusion/Rearrangement Panel, Next-Generation Sequencing, Tumor.
Shipping Instructions
Advise Express Mail or equivalent if not on courier service.
Necessary Information
1. A pathology report is required for testing to be performed. If not provided, appropriate testing and/or interpretation may be compromised or delayed. Acceptable pathology reports include working drafts, preliminary pathology, or surgical pathology reports.
2. The following information must be included in the report provided.
-Patient name
-Block number - must be on all blocks, slides, and paperwork
-Date of collection
-Tissue source
3. A reason for testing must be provided. If this information is not provided, an appropriate indication for testing may be entered by Mayo Clinic Laboratories.
Specimen Required
Submit only 1 of the following specimens:
Preferred
Specimen Type: Tissue block
Collection Instructions: Submit a formalin-fixed, paraffin-embedded tumor tissue block. Blocks prepared with alternative fixation methods may be acceptable; provide fixation method used.
Acceptable
Specimen Type: Tissue slides
Slides: 1 Hematoxylin and eosin stained and 4 unstained
Collection Instructions: Submit 1 slide stained with hematoxylin and eosin and 4 consecutive unstained, positively-charged, unbaked slides with 5 micron-thick sections of the tumor tissue.
Specimen Minimum Volume
Slides: 1 Hematoxylin and eosin stained and 2 unstained
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Tissue | Ambient (preferred) | ||
| Refrigerated | |||
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Clinical Information
The Ewing sarcoma breakpoint region 1 (EWSR1) gene encodes a protein with numerous complex activities within the cell including acting as a transcriptional regulator and mediating the activity of other proteins.(1) Oncogenic fusion of EWSR1 at 22q12 with FLI1 at 11q24 resulting from t(11;22) or with ERG at 21q22 resulting from t(21;22) was initially shown to be associated with and characteristic of Ewing sarcoma. Fusion of EWSR1 with various partner genes has since been identified in a wide variety of neoplasms.
Reference Values
An interpretive report will be provided.
Interpretation
A neoplastic clone is detected when the percent of cells with an abnormality exceeds the normal cutoff for the Ewing sarcoma breakpoint region 1 (EWSR1) fluorescence in situ hybridization (FISH) probe set
A positive result is consistent with the presence of EWSR1 rearrangement and likely reflects EWSR1 fusion with a partner gene. The significance of this FISH result is dependent on clinical and pathologic features.
A negative result does not exclude the presence of a neoplastic disorder.
Cautions
This test is not approved by the US Food and Drug Administration and 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 fluorescence in situ hybridization (FISH) assays. Non-formalin fixed specimens will not be rejected.
Paraffin-embedded tissues that have been decalcified may not be successful for FISH analysis. The success rate of FISH studies on decalcified tissue is approximately 50%, but FISH will be attempted if sufficient tumor is present for analysis.
If no FISH signals are observed post-hybridization, the case will be released indicating a lack of FISH results.
Method Description
This test is performed using a commercially available Ewing sarcoma breakpoint region 1 (EWSR1) dual-color, break-apart strategy probe (BAP). Paraffin-embedded tissue samples are cut at 5 microns and mounted on positively charged glass slides. The selection of tissue and the identification of target areas on the hematoxylin and eosin (H and E)-stained slide are performed by a pathologist. Using the H and E-stained slide as a reference, target areas are etched with a diamond-tipped engraving tool on the back of the unstained slide to be assayed. The probe set is hybridized to the appropriate target areas, and 2 technologists independently analyze 50 interphase nuclei (100 total) with the results expressed as the percent of abnormal nuclei.(Unpublished Mayo method)
Day(s) Performed
Monday through Friday
Report Available
7 to 10 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
88271x2
88291 - NA 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)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| EWSF | EWSR1 (22q12), FISH, Ts | 93806-8 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 52187 | Result Summary | 50397-9 |
| 52189 | Interpretation | 69965-2 |
| 54589 | Result | 62356-1 |
| CG749 | Reason for Referral | 42349-1 |
| 52190 | Specimen | 31208-2 |
| 52191 | Source | 31208-2 |
| 52192 | Tissue ID | 80398-1 |
| 52193 | Method | 85069-3 |
| 55030 | Additional Information | 48767-8 |
| 53827 | Disclaimer | 62364-5 |
| 52194 | Released By | 18771-6 |