Neuroblastoma, 2p24 (MYCN) Amplification, FISH
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
As a prognostic factor for patients with neuroblastoma
As an aid to treatment decisions in some patients with neuroblastoma
Fluorescence In Situ Hybridization (FISH)
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
MYCN, 2p24, FISH, Ts
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.
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.
Specimen Type: Paraffin-embedded tissue block
Collection Instructions: Submit formalin-fixed, paraffin-embedded tumor tissue block and include 1 hematoxylin-and-eosin stained slide.
Acceptable: 3 unstained, 5-micron-thick sections mounted on positively charged microscope slides.
Additional Information: Advise Express Mail or equivalent if not on courier service.
Forms: If not ordering electronically, submit a Cytogenetics Hematologic Disorders Request Form (Supply T607) 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.
Tissue: paraffin-embedded whole tissue block or or onefour 5- micron thick sections mounted on positively charged microscope slides plus 1 hematoxylin-and-eosin eosin (H&E) stained slide/Bone marrow: 1 mL
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
Neuroblastoma is a solid tumor that occurs in early childhood and is usually found in the adrenal glands, but rarely is found in other areas of the body. Approximately 25% of all neuroblastomas have amplification of the MYCN oncogene, located on chromosome 2 at p24.1. Amplification of the MYCN oncogene correlates with an unfavorable prognosis and aggressive disease.
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.
MYCN gene amplification is detected when the percent of cells with an abnormality exceeds the normal cutoff for the MYCN probe. A positive result is consistent with MYCN gene amplification. A negative result suggests no MYCN gene amplification. However, this result does not exclude the diagnosis of neuroblastoma.
Specimens will be considered within normal limits if they have an MYCN-to-D2Z1 ration of 1.00 to 2.00, which indicates there are an equal number of copies of the MYCN oncogene and the centromere 2. Specimens are considered amplified if they have a ratio of > or =4.00.
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 is best used as an adjunct to existing clinical and pathologic information.
This test is not diagnostic for neuroblastoma. Other tumors including medulloblastoma, retinoblastoma, astrocytoma, and small cell lung cancer may have amplification of MYCN.
A blinded study using the MYCN amplification probe set was performed on 52 formalin-fixed, paraffin-embedded specimens, including 22 neuroblastoma specimens from 17 patients, 20 normal adrenal glands, and 10 Wilm's tumors. Of the 22 neuroblastoma specimens, 2 were found to be amplified and 20 were within normal limits. Fourteen of the neuroblastoma specimens were previously tested by Southern blot analysis and the 2 cases exhibiting amplification by FISH were also shown to be amplified by Southern blot. The remaining 12 specimens were found to be normal by both FISH and Southern blot. All 20 normal adrenals were found to be within normal limits. Nine of 10 Wilm's tumors were found to be within normal limits. One of the Wilm's tumors was found to be duplicated but not amplified. Duplications have a different mechanism for gaining MYCN oncogene copies and do not lead to MYCN protein overexpression.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Ambros PF, Ambros IM, SIOP Europe Blastoma Pathology, Biology, and Bone Marrow Group: Pathology and biology guidelines for resectable and unresectable neuroblastic tumors and bone marrow examination guidelines. Med Pediatr Oncol 2001 Dec;37(6):492-504
2. Spitz R, Hero B, Skowron M, et al: MYCN-status in neuroblastoma: characteristics of tumours showing amplification, gain, and non-amplification. Eur J Cancer 2004 Dec;40(18):2753-2759
3. Valent A, Le Roux G, Barrois M, et al: MYCN gene overrepresentation detected in primary neuroblastoma tumour cells without amplification. J Pathol 2002 Dec;198(4):495-501
4. Schwab M: Amplified MYCN in human neuroblastoma: paradigm for the translation of molecular genetics to clinical oncology. Ann NY Acad Sci 2002 Jun;963:63-73
Method Description Describes how the test is performed and provides a method-specific reference
The test uses a dual-color FISH probe strategy with an MYCN probe and a chromosome 2 alpha-satellite centromere probe (D2Z1) (Abbott Molecular). Paraffin-embedded tissues are cut at 5 microns and mounted on positively charged glass slides. Four slides are prepared, with 1 slide stained with hematoxylin-and-eosin (H and E). The selection of tissue and the identification of target areas on the 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 analyze 30 interphase nuclei each (100-300 cells) with the results expressed as a ratio of the total number of MYCN signals compared to the total number of D2Z1 signals.(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, 8 a.m.-5 p.m. 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.
88271 x 2-DNA probe, each
88274-Interphase in situ hybridization, analyze 25-99 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|
|CG191||Reason For Referral||42349-1|