Alveolar Rhabdomyosarcoma (ARMS), 13q14 (FOXO1 or FKHR) Rearrangement, FISH, Tissue
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Supporting the diagnosis of alveolar rhabdomyosarcomas (ARMS) when used in conjunction with an anatomic pathology consultation
An aid in the diagnosis of ARMS when reverse transcriptase-PCR results are equivocal or do not support the clinical picture
Testing Algorithm Delineates situation(s) when tests are added to the initial order. This includes reflex and additional tests.
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.
Fluorescence In Situ Hybridization (FISH)
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
FOXO1 (FKHR), 13q14, FISH
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Please provide a pathology report with each specimen. The laboratory will not reject a specimen that arrives without this information but will hold the specimen until a pathology report is received.
Submit only 1 of the following specimens:
Preferred: Formalin-fixed, paraffin-embedded tumor tissue block and 1 hematoxylin and eosin (H and E)-stained slide
Acceptable: Four consecutive, unstained, 5 micron-thick sections placed on positively-charged slides and 1 H and E-stained slide
Forms: If not ordering electronically, complete and submit a Hematopathology/Molecular Oncology Request Form (Supply T241) with the specimen.
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
2 unstained slides and 1 hematoxylin-and-eosin (H and E) slide
Note: No specimen should be rejected. If specimen not received at appropriate temperature or in wrong anticoagulant, include note to laboratory. If questions, contact laboratory.
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
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.
The alveolar form consists of 2 variants; classic and solid. The classic form is characterized by small round cells with dark hyperchromatic nuclei containing distinct nucleoli, held together by strands of intercellular collagen, thereby creating a cellular architecture resembling the alveolar spaces of the lungs. The solid form is characterized by a similar cellular morphology but without the formation of alveolar spaces. ARMS are also members of the small round cell tumor group that includes synovial sarcoma, lymphoma, Wilms tumor, Ewing sarcoma, and desmoplastic small round cell tumor.
Most cases of ARMS (75%) are associated with a t(2;13)(q35;q14), where a chimeric gene is formed from the rearrangement of the PAX3 gene on chromosome 3 and the FOXO1(FKHR) gene on chromosome 13. A small subset of ARMS patients (10%) are associated with a variant translocation, t(1;13)(q36;q14), involving the PAX1 gene of chromosome 1 and the FOXO1 gene. Detection of these transcripts by RT-PCR (83367 Alveolar Rhabdomyosarcomas (ARMS) by Reverse Transcriptase PCR, Paraffin), which allows specific identification of the t(2;123) and t(1;13), has greatly facilitated the diagnosis of ARMS tumors. FISH analysis (using the FOXO1(FKHR) probe) adds the ability to detect variant FOXO1 rearrangements not detectible by PCR, and will often yield results when the quality of the available RNA is poor or the PCR results are equivocal.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
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 FOXO1 FISH probe.
A positive result suggests rearrangement of the FOXO1 gene region at 13q14 and is consistent with a subset of alveolar rhabdomyosarcomas (ARMS).
A negative result suggests FOXO1 gene rearrangement is not present, but does not exclude the diagnosis of ARMS.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
This test is not approved by the FDA 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. Although FISH testing will not be rejected due to non-formalin fixation results may be compromised.
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.
FISH analysis was performed on 36 formalin-fixed, paraffin-embedded tissues including 14 SS tumors and 22 non-cancerous controls or non-SS tumors. The normal controls were used to generate a normal cutoff for this assay. Each SS specimen was previously characterized to carry the t(X;18) via reverse transcriptase-PCR analysis. Eleven tumors had the SSX1 translocation partner and 3 tumors had the SSX2 translocation partner. Rearrangement of SS18 was identified in all 14 SS specimens with the expected break-apart signal pattern observed in 10 patients and 4 patients demonstrated atypical break-apart signal patterns.
FISH analysis using this method was performed on 42 formalin-fixed paraffin-embedded tissues including 17 rhabdomyosarcomas and 25 noncancerous soft tissue control specimens (from various anatomic locations). The normal controls were used to generate a normal cutoff for this assay. Rearrangement of FOXO1 was identified in 10 of 17 (59%) alveolar rhabdomyosarcoma specimens.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Alveolar rhabdomyosarcoma. In Who Health Organization Classification of Tumors. Pathology and Genetics Tumours of Soft Tissue and Bone. Edited by CDM Fletcher, KK Unni, F Mertens: IARC Press; Lyon 2002, pp 150-152
2. 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 Nov;5(3):230-235
3. 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 Jun;86(6):547-556
4. Ladanyi M. Bridge JA: Contribution of molecular genetic data to the classification of sarcomas. Hum Pathol 2000 May;31(5):532-538
5. Edwards RH, Chaten J, Xiong QB, Barr FG: Detection of gene fusions in rhabdomyosarcoma by reverse transcriptase-polymerase chain reaction assay of archival samples. Diagn Mol Pathol 1997 Apr;6(2):91
6. Lae ME, Roche PC, Jin L, et al: Desmoplastic small round cell tumor: a clinicopathologic, immunohistochemical, and molecular study of 32 tumors. Am J Surg Pathol 2002 Jul;26(7):823-835
Method Description Describes how the test is performed and provides a method-specific reference
The test uses a commercially available FOXO1 dual-color, break-apart probe (BAP) strategy. Formalin-fixed, paraffin-embedded tissues are cut at 5 microns and mounted on positively-charged glass slides. The selection of 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 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 each (100 total) with the results expressed as a percent abnormal nuclei.(Unpublished Mayo method)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Samples processed Monday through Sunday. Results reported Monday through Friday 8am-5pm CST
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test
Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
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 Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
Alveolar Rhabdomyosarcoma (ARMS), 13q14 (FOXO1 or FKHR) Rearrangement, FISH, Tissue
88271 x 2-DNA probe, each
88275-Interphase in situ hybridization, 100-300 cells
88291-Interpretation and report
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
|Result ID||Reporting Name||LOINC Code|
|CG121||Reason For Referral||42349-1|