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HelpTest Code BILAO Biliary Tract Malignancy, FISH, Varies
Specimen Required
Supplies: PreservCyt Vial (T536)
Specimen Type: Bile duct brushing, bile duct aspirate, hepatobiliary brushing, or hepatobiliary aspirate (fine-needle aspiration is not acceptable)
Container/Tube: Separate ThinPrep vial, containing 20 mL PreservCyt or CytoLyt solution for each specimen
Specimen Volume: Entire collection
Collection Instructions:
1. If performing local cytology in addition to fluorescence in situ hybridization testing, aliquot half of the specimen into another ThinPrep vial before processing the specimen.
2. Submission of residual specimen (after processing other testing) may compromise the sensitivity of the test.
3. Label each specimen with specific source (eg, right hepatic duct or common bile duct).
Forms
Useful For
Assessing bile duct brushing or hepatobiliary brushing specimens for biliary tract malignancy
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| BILOB | Biliary Tract Malignancy, FISH | No | No |
| BILOC | Biliary Tract Malignancy, FISH | No | No |
| BILOD | Biliary Tract Malignancy, FISH | No | No |
| BILOE | Biliary Tract Malignancy, FISH | No | No |
| BILOF | Biliary Tract Malignancy, FISH | No | No |
Testing Algorithm
When this test is ordered, fluorescence in situ hybridization testing will be performed. When additional specimens are received, the laboratory will add BILOB to the second specimen, BILOC to the third specimen, and so on.
Special Instructions
Method Name
Fluorescence In Situ Hybridization (FISH)
Reporting Name
Biliary Tract Malignancy, FISHSpecimen Type
VariesSpecimen Minimum Volume
See Specimen Required
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Varies | Refrigerated (preferred) | ||
| Ambient | |||
Reject Due To
| Pancreatic mass Pancreatic cyst Pancreatic fine-needle aspiration (FNA) Â |
Reject |
Clinical Information
Endoscopic retrograde cholangiopancreatography (ERCP) is used to examine patients with biliary tract obstruction or stricture for possible malignancy. Biopsies and cytologic specimens are obtained at the time of ERCP. Cytologic analysis complements biopsy by sometimes detecting malignancy in patients with a negative biopsy. Nonetheless, a number of studies suggest that the overall sensitivity of bile duct brushing and bile aspirate cytology is quite low.
Fluorescence in situ hybridization (FISH) is a technique that utilizes fluorescently-labeled DNA probes to examine cells for chromosomal alterations. FISH can be used to detect cells with chromosomal changes (eg, aneuploidy) that are indicative of malignancy. Studies in our laboratory indicate that the sensitivity of FISH to detect malignant cells in biliary brush specimens is superior to that of conventional cytology.
Reference Values
No abnormality detected by fluorescence in situ hybridization
Interpretation
An interpretive report will be provided.
Cautions
A positive fluorescence in situ hybridization (FISH) result does not identify location or type of malignancy. FISH abnormalities may be associated with high-grade dysplasia or carcinoma in situ. Cytology and biopsy may help clarify such situations.
Supportive Data
Cell counts using the biliary fluorescence in situ hybridization (FISH) probe set on pancreatobiliary brushings were compared between 49 patients with malignancy and 41 patients without malignancy to determine normal value cutoffs for this assay. The cutoff values were independently validated in a blinded study from brushing samples collected from 112 patients at the time of endoscopic retrograde cholangiopancreatography. Among patients with malignancy on follow-up, the sensitivity of a polysomy FISH result was significantly superior to cytology (74% vs. 28%, P<0.001). The specificity of FISH and cytology were similar (96% vs. 100%).
Method Description
Biliary cells are harvested, fixed, and placed on a slide. Fluorescently labeled DNA probes to 1q21 (MCL1), 7p12 (EGFR), 8q24 (MYC), and 9p21 (CDKN2A) (Abbott Molecular, Inc) are hybridized to the cells on the slide. The slide is then washed and stained with DAPI (4',6-diamidine-2'-phenylindole dihydrochloride, a nuclear counterstain). Fluorescence microscopy with unique band filters is used to assess 100 consecutive epithelial cells for gains and losses of probe signals (chromosomal loci). Specimens are considered abnormal if cell counts exceed predetermined cutoff values for one or more of the following abnormalities: polysomy, homozygous 9p21 loss, single locus gain, single locus gain with 9p21 loss in the same cells, and/or tetrasomy. If the cutoff for polysomy is not attained in the 100-cell enumeration, then the remainder of the slide is assessed for polysomy until the cutoff is reached or the slide is exhausted.(Unpublished Mayo method)
Day(s) Performed
Monday through Friday
Report Available
7 to 10 daysSpecimen Retention Time
Until reportedPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
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 US Food and Drug Administration.CPT Code Information
88377
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| BILAO | Biliary Tract Malignancy, FISH | 95229-1 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 71918 | Result Summary | 50397-9 |
| 71919 | Result | 95229-1 |
| 71920 | Interpretation | 69965-2 |
| 71921 | Reason for Referral | 42349-1 |
| 71922 | Specimen | 31208-2 |
| MC029 | Source | 39111-0 |
| MC030 | Fixation | 8100-0 |
| MC031 | Collection Method | 33724-6 |
| MC032 | Clinical History | 22636-5 |
| 71927 | Method | 85069-3 |
| 71928 | Released By | 18771-6 |