Supporting the diagnosis of Ewing sarcoma (EWS)/primitive neuroectodermal tumor, myxoid chondrosarcoma, desmoplastic small, round cell tumor, clear cell sarcoma, and myxoid liposarcoma when used in conjunction with an anatomic pathology consultation
An aid in the diagnosis of EWS when reverse transcriptase-polymerase chain reaction results are equivocal or do not support the clinical picture
| 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 |
This test does not include a pathology consult. If a pathology consultation is requested, PATHC / Pathology Consultation should be ordered and the appropriate fluorescence in situ hybridization (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 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.
See the Method Description for specific details.
Fluorescence In Situ Hybridization (FISH)
This test does not include a pathology consult. If a pathology consultation is requested, PATHC / Pathology Consultation should be ordered and the appropriate fluorescence in situ hybridization (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 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.
See the Method Description for specific details.
Tissue
Advise Express Mail or equivalent if not on courier service.
1. A pathology report is required for testing to be performed. Acceptable pathology reports include working drafts, preliminary pathology or surgical pathology reports.
2. 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.
| Question ID | Description | Answers |
|---|---|---|
| CG749 | Reason for Referral |
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.
If not ordering electronically, complete, print, and send an Oncology Test Request (T729) with the specimen.
Two consecutive, unstained, 5 micron-thick sections placed on positively charged slides and 1 hematoxylin and eosin-stained slide
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Tissue | Ambient (preferred) | ||
| Refrigerated | |||
Supporting the diagnosis of Ewing sarcoma (EWS)/primitive neuroectodermal tumor, myxoid chondrosarcoma, desmoplastic small, round cell tumor, clear cell sarcoma, and myxoid liposarcoma when used in conjunction with an anatomic pathology consultation
An aid in the diagnosis of EWS when reverse transcriptase-polymerase chain reaction results are equivocal or do not support the clinical picture
This test does not include a pathology consult. If a pathology consultation is requested, PATHC / Pathology Consultation should be ordered and the appropriate fluorescence in situ hybridization (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 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.
See the Method Description for specific details.
Ewing sarcoma/primitive neuroectodermal tumors are members of the small, round cell group of tumors that are thought to originate in cells of primitive neuroectodermal origin with variable degrees of differentiation. The small, round cell group of tumors also includes rhabdomyosarcomas, desmoplastic small, round cell tumors, and poorly differentiated synovial sarcomas. Although immunohistochemical markers can be helpful in the correct diagnosis of these tumors, recent molecular studies have shown the specificity of molecular markers in differentiating specific subtypes of small, round blue-cell tumors. Accurate diagnosis of each tumor type is important for appropriate clinical management of patients.
Ewing tumors are characterized cytogenetically by rearrangements of the EWSR1 gene at 22q12 with FLI1 at 11q24 (t[11;22]) or ERG at 21q22 (t[21;22]) in 85% and 5% to 10% of Ewing tumors, respectively. Less than 1% of cases may have other fusion partners such as ETV1 at 7p22, E1AF at 17q12, or FEV at 2q33.
An interpretive report will be provided.
A neoplastic clone is detected when the percent of cells with an abnormality exceeds the normal cutoff for the EWSR1 FISH probe set.
A positive result is consistent with a diagnosis of Ewing sarcoma (EWS)/primitive neuroectodermal tumors (PNET).
A negative result suggests that a EWSR1 rearrangement is not present but does not exclude the diagnosis of EWS/PNET.
This test is not approved by the U.S. 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, however non-formalin 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.
Fluorescence in situ hybridization analysis was performed on 38 formalin-fixed, paraffin-embedded tissue samples, including 16 tumors, and 22 noncancerous control specimens. The normal controls were used to generate a normal cutoff for this assay. Rearrangement of EWSR1 was identified in 14 tumor specimens and 2 yielded no results due to poor hybridization.
1. Fletcher CDM, Unni KK, Mertens F, eds. World Health Organization Classification of Tumors. Pathology and Genetics Tumours of Soft Tissue and Bone. IARC Press; 2002:298-300
2. Burchill SA: Ewing's sarcoma: diagnostic, prognostic, and therapeutic implications of molecular abnormalities. J Clin Pathol. 2003 February;56(2):96-102. doi: 10.1136/jcp.56.2.96
3. Riley RD, Burchill SA, Abrams KR, et al: A systematic review of molecular and biological markers in tumors of the Ewing's sarcoma family. Eur J Cancer. 2003 January;39:19-30. doi: 10.1016/s0959-8049(02)00500-2
4. Romeo S, Dei Tos AP: Soft tissue tumors associated with EWSR1 translocation. Virchows Arch. 2010 Feb;456(2):219-34. doi: 10.1007/s00428-009-0854-3
This test is performed using a commercially available EWSR1 dual-color, break-apart strategy probe (BAP). Formalin fixed paraffin-embedded tissues 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 is performed by a pathologist. Using the H and E-stained slide as a reference, target areas are etched with a diamond tipped etcher on the back of the unstained slide to be assayed. The probe set is hybridized to the appropriate target areas and 2 technologists each analyze 50 interphase nuclei (100 total) with the results expressed as the percent of abnormal nuclei.(Unpublished Mayo method)
Monday through Friday
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 US Food and Drug Administration.
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)
| Test Id | Test Order Name | Order LOINC Value |
|---|---|---|
| EWSF | EWSR1 (22q12), FISH, Ts | 93806-8 |
| Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
|---|---|---|
| 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 |
| 52194 | Released By | 18771-6 |
| 53827 | Disclaimer | 62364-5 |