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Test ID: FOXOF Alveolar Rhabdomyosarcoma (ARMS), 13q14 (FOXO1 or FKHR) Rearrangement, FISH, Tissue

Useful For

Supporting the diagnosis of alveolar rhabdomyosarcomas when used in conjunction with an anatomic pathology consultation

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

FOXO1 (13q14), ARMS, FISH, Ts

Specimen Type

Tissue


Ordering 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.

1. Patient name

2. Block number - must be on all blocks, slides, and paperwork

3. Date of collection

4. 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 (FFPE) tumor tissue block. Blocks prepared with alternative fixation methods will be attempted but are less favorable for successful results by FISH testing; provide fixation method used.

Additional Information:

1. Paraffin-embedded specimens can be from any anatomic location (skin, soft tissue, lymph node, etc).

2. Bone specimens that have been decalcified will be attempted for testing, but the success rate is approximately 50%.

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Acceptable

Specimen Type: Tissue slides

Slides: 1 Hematoxylin and eosin stained and 4 unstained?

Collection Instructions: Submit 4 consecutive unstained, positively charged, unbaked slides with 5 micron-thick sections of the tumor tissue and 1 slide stained with hematoxylin and eosin.


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 

Clinical Information

Rhabdomyosarcomas are a heterogeneous group of malignant tumors showing skeletal muscle differentiation. They can be divided into 3 subtypes: alveolar, embryonal, and pleomorphic. The rarer alveolar rhabdomyosarcomas (ARMS) are seen in older children, are more likely to occur in limbs, and are associated with higher stage disease and an unfavorable prognosis.

 

Most cases of ARMS are associated with the rearrangement of the FOXO1 gene on chromosome 13. Detection of a FOX01 rearrangement by FISH may help to support a histologic diagnosis of ARMS.

Reference Values

An interpretive report will be provided.

Interpretation

FOXO1 will be clinically interpreted as positive or negative.

 

A neoplastic clone is detected when the percent of cells with an abnormality exceeds the normal cutoff for the FOXO1 probe set.

 

A positive result is consistent with rearrangement of the FOXO1 gene and likely reflects FOXO1 fusion with a partner gene. The significance of this finding is dependent on the clinical and pathologic features.

 

A positive result is consistent with rearrangement of the FOXO1 gene, likely reflects FOXO1 fusion with a partner gene, and is consistent with a subset of alveolar rhabdomyosarcomas (ARMS). The significance of this finding is dependent on the clinical and pathologic features.

 

A negative result suggests a FOXO1 gene rearrangement is not present but does not exclude the diagnosis of ARMS.

Clinical Reference

1. Galili N, Davis RJ, Fredericks WJ, et al: Fusion of a fork head domain gene to PAX3 in the solid tumor alveolar rhabdomyosarcoma. Nat Genet. 1993;5(3):230-235

2. Nishio J, Althof PA, Bailey JM, et al. Use of a novel FISH assay on paraffin-embedded tissues as an adjunct to diagnosis of alveolar rhabdomyosarcoma. Lab Invest. 2006;86(6):547-556

3. Barr FG. Gene fusions involving PAX and FOX family members in alveolar rhabdomyosarcoma. Oncogene. 2001;20(40):5736-5746

4. WHO Classification of Tumours Editorial Board. Soft tissue and bone tumours. 5th ed. IARC; 2020. WHO Classification of Tumours Series. Vol. 3, 203-208

Day(s) Performed

Monday through Friday

Report Available

7 to 10 days

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

88271 x 2, 88291-DNA probe, each (first probe set), Interpretation and report

88271 x 2-DNA probe, each; each additional probe set (if appropriate)

88271-DNA probe, each; coverage for sets containing 3 probes (if appropriate)

88271 x 2-DNA probe, each; coverage for sets containing 4 probes (if appropriate)

88271 x 3-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
FOXOF FOXO1 (13q14), ARMS, FISH, Ts 93807-6

 

Result ID Test Result Name Result LOINC Value
52211 Result Summary 50397-9
52213 Interpretation 69965-2
52389 Result 62356-1
CG752 Reason for Referral 42349-1
52214 Specimen 31208-2
52215 Source 31208-2
52216 Tissue ID 80398-1
52217 Method 85069-3
54592 Additional Information 48767-8
52824 Disclaimer 62364-5
52218 Released By 18771-6

Forms

If not ordering electronically, complete, print, and send an Oncology Test Request (T729) with the specimen.

Mayo Clinic Laboratories | Genetics and Genomics Additional Information:

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