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HelpMayo Test ID PRKAF Fibrolamellar Carcinoma, 19p13.1 (PRKACA) Rearrangement, FISH, Tissue
Necessary Information
1. A pathology report is required in order 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.
Specimen Required
Submit only 1 of the following specimens:
Specimen Type: Tissue
Container/Tube: Formalin-fixed, paraffin-embedded tumor tissue block
Specimen Type: Slides
Slides/Slide Count: Three consecutive, unstained, 5 micron-thick sections placed on positively charged slides, and 1 hematoxylin and eosin-stained slide
Useful For
Aid in the diagnosis of identifying PRKACA gene rearrangements of patients with fibrolamellar carcinoma
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| _PBCT | Probe, +2 | No | No |
| _PADD | Probe, +1 | No | No |
| _PB02 | Probe, +2 | No | No |
| _PB03 | Probe, +3 | No | No |
| _IL25 | Interphases, <25 | No | No |
| _I099 | Interphases, 25-99 | No | No |
| _I300 | Interphases, >=100 | No | No |
Testing Algorithm
This test does not include a pathology consultation. If a pathology consultation is requested, PATHC / Pathology Consultation should be ordered, and the appropriate fluorescence in situ hybridization test will be performed at an additional charge.
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
PRKACA, Rearrangement, FISH, TsSpecimen Type
TissueSpecimen Minimum Volume
Two 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.Clinical Information
DNAJB1-PRKACA fusion has been associated with a distinct subtype of hepatocellular carcinoma called fibrolamellar carcinoma. A break-apart strategy FISH probe has been developed to detect the rearrangement event that occurs in the DNAJB1-PRKACA fusion, specifically the loss of the 5' region labeled in red and retention of the 3' region labeled in green.
Reference Values
An interpretive report will be provided.
Interpretation
A positive result with the PRKACA probe is detected when the percent of cells with an abnormality exceeds the normal cutoff for the probe set.
A positive result of PRKACA suggests fusion of the PRKACA and DNAJB1 genes at 19p13.1. A negative result suggests no fusion of the PRKACA and DNAJB1 genes has occurred.
Cautions
This test is not approved by the US Food and Drug Administration, and it is best used as an adjunct to existing clinical and pathologic information.
Fixatives other than formalin (eg, Prefer, Bouin) may not be successful for 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.
Clinical Reference
R Graham, L Jin, D Knutson, S Kloft-Nelson, et al: DNAJB1-PRKACA is specific for fibrolamellar carcinoma. Mod Path 2015;28:822-829
Method Description
This test uses a laboratory developed PRKACA (19p13.1) 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 tissue and the identification of target areas on the hematoxylin and eosin (H and E)-stained slide are 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 probes are hybridized to the appropriate target areas and 2 technologists analyze each probe set. Using the PRKACA probe set, each technologist analyzes 50 interphase nuclei (100 total) and the results are expressed as the percent of abnormal nuclei.(Unpublished Mayo method)
Day(s) Performed
Monday through Friday
Report Available
7 to 10 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
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
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)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| PRKAF | PRKACA, Rearrangement, FISH, Ts | 104670-5 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 40669 | Result Summary | 50397-9 |
| 40670 | Interpretation | 69965-2 |
| 40671 | Result | 62356-1 |
| 40672 | Reason for Referral | 42349-1 |
| 40673 | Specimen | 31208-2 |
| 40674 | Source | 31208-2 |
| 40675 | Tissue ID | 80398-1 |
| 40676 | Method | 85069-3 |
| 40677 | Additional Information | 48767-8 |
| 40678 | Disclaimer | 62364-5 |
| 40679 | Released By | 18771-6 |