Test ID FGFR2 FGFR2 (10q26.1) Rearrangement, FISH, Tissue
Useful For
Providing prognostic information and guiding treatment for patients with cholangiocarcinomas and other tumor types including bladder, thyroid, oral cavity, and brain
Reflex Tests
Test ID | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
_IL25 | Interphases, <25 | No, (Bill Only) | No |
_I099 | Interphases, 25-99 | No, (Bill Only) | No |
_I300 | Interphases, ≥100 | No, (Bill Only) | No |
_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 |
Testing Algorithm
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.
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.
Method Name
Fluorescence In Situ Hybridization (FISH)
Reporting Name
FGFR2 (10q26.1), FISH, TsSpecimen Type
TissueProvide 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:
Specimen Type: Tissue
Container/Tube: Formalin-fixed, paraffin-embedded tumor tissue block
Specimen Type: Slides
Specimen Volume: 4 Consecutive, unstained, 5-micron thick sections placed on positively charged slides and 1 hematoxylin and eosin-stained slide
Specimen 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 |
---|---|---|
Tissue | Ambient (preferred) | |
Refrigerated |
Clinical Information
Cholangiocarcinoma is a malignancy arising from the biliary tract epithelium. These tumors are often clinically advanced at the time of presentation and the prognosis is very poor with a short overall survival. Treatment is generally limited to surgical resection, which is associated with a high degree of morbidity, and palliative chemotherapy regimens. Therefore, additional treatment options are eagerly sought.
Rearrangement of the FGFR2 gene region has been identified in a subset of cholangiocarcinomas. These rearrangements result in overexpression of FGFR2, which offers the possibility of using targeted FGFR2-inhibitor therapy for treatment. FGFR2 rearrangement has been identified in a number of other cancers including those of the bladder, thyroid, oral cavity, and brain. In the future, it is likely that the presence of FGFR2 rearrangements will be exploited in the treatment of these cancers as well.
Reference Values
An interpretive report will be provided.
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, nonformalin 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.
Day(s) Performed
Samples processed Monday through Sunday. Results reported Monday through Friday, 8 a.m. to 5 p.m. CT.
Performing Laboratory

Test Classification
This test was developed and its performance characteristics 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
88271x2, 88291 – DNA probe, each (first probe set), Interpretation and report
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)