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HelpTest Code GLIOF 1p/19q Deletion in Gliomas, FISH, Tissue
Useful For
Aids in diagnosing oligodendroglioma tumors and predicting the response of an oligodendroglioma to therapy
May be useful in tumors with a complex "hybrid" morphology requiring differentiation from pure astrocytomas to support the presence of oligodendroglial differentiation/lineage
Indicated when a diagnosis of oligodendroglioma, both low-grade World Health Organization (WHO, grade II) and anaplastic (WHO, grade III) is rendered
Strongly recommended when a diagnosis of mixed oligoastrocytomas is rendered
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| _I099 | Interphases, 25-99 | No, (Bill Only) | No |
| _I300 | Interphases, >=100 | No, (Bill Only) | No |
| _IL25 | Interphases, <25 | 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 |
| _PBCT | Probe, +2 | No, (Bill Only) | No |
Testing Algorithm
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 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.
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.
Chromosomal microarray (CMAPT / Chromosomal Microarray, Tumor, Formalin-Fixed Paraffin-Embedded), rather than FISH, may be of benefit to evaluate for acquired alterations associated with the molecular classification of glioma.(1) For more information and frequently asked questions, see Clarity on Reason for and Benefits of Chromosomal Microarray.
Reporting Name
1p/19q Deletion, Glioma, FISH, TsSpecimen Type
TissueShipping Instructions
Advise Express Mail or equivalent if not on courier service.
Necessary Information
A reason for testing and pathology report are required in order for testing to be performed. Send information with specimen. Acceptable pathology reports include working drafts, preliminary pathology, or surgical pathology reports.
Specimen Required
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: Six consecutive, unstained, 5 micron-thick sections placed on positively charged slides, and 1 hematoxylin and eosin-stained slide.
Specimen Minimum Volume
Four consecutive, unstained, 5-micron-thick sections placed on positively charged slides and 1 hematoxylin and eosin-stained slide
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.Reference Values
An interpretive report will be provided.
Day(s) Performed
Monday through Friday
Report Available
8 to 12 daysSpecimen Retention Time
Slides and H&E used for analysis are retained by the laboratory in accordance to CAP and NYS requirements. Client provided paraffin blocks and extra unstained slides (if provided) will be returned after testing is complete.Performing Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
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)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| GLIOF | 1p/19q Deletion, Glioma, FISH, Ts | In Process |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 52107 | Result Summary | 50397-9 |
| 52109 | Interpretation | 69965-2 |
| 52108 | Result | 62356-1 |
| CG739 | Reason For Referral | 42349-1 |
| 52110 | Specimen | 31208-2 |
| 52111 | Source | 31208-2 |
| 52112 | Tissue ID | 80398-1 |
| 52113 | Method | 85069-3 |
| 54579 | Additional Information | 48767-8 |
| 53836 | Disclaimer | 62364-5 |
| 52114 | Released By | 18771-6 |
Forms
If not ordering electronically, complete, print, and send an Oncology Test Request (T729) with the specimen.
Supportive Data
Adult gliomas are classified by IDH-mutation and 1p/19q codeletion status.(1)
|
Tumor classification |
IDH-mutation |
1p/19q codeletion status |
|
Glioblastoma |
IDH-wildtype |
Never have whole arm codeletion by CMAPT, can rarely have codeletion by FISH (due to small deletions that include the FISH probes). May have +19, 19p+ or 19q+ (one or both of the FISH probes gained) |
|
Astrocytoma |
IDH-mutant |
Never have whole arm codeletion by CMAPT, can rarely have codeletion by FISH (due to small deletions that include the FISH probes). May have 19q- (loss of the FISH probe, with retention of the 1p, 1q and 19p probes). |
|
Oligodendroglioma |
IDH-mutant |
Defined by whole arm codeletion by CMAPT and loss of the 1p and 19q FISH probes |