Gastrointestinal Stromal Tumor Mutations
Ordering Recommendation
Use to detect activating mutations in KIT and PDGFRA. Predict response to tyrosine kinase inhibitor (TKI) therapy.
New York DOH Approval Status
Specimen Required
Tumor tissue.
Formalin fix (10 percent neutral buffered formalin) and paraffin embed tissue.
Diff-Quik- and Papanicolaou-stained cytology smears are also acceptable. Number of slides needed is dependent on the tumor cellularity of the smear. Slide(s) will be destroyed during testing process and will not be returned to client. Protect from excessive heat. Transport block and/or slides in a tissue transport kit (ARUP supply #47808) available online through eSupply using ARUP Connect™ or contact ARUP Client Services at 800-522-2787.
Resections: Transport 8 unstained 5-micron slides. (Min: 5 slides)
Small Biopsies: Transport 15 unstained 5-micron slides. (Min: 10 slides)
New York State Clients: Transport tissue (Formalin-fixed, paraffin embedded) or 10 unstained, nonbaked slides and 1 slide stained with hematoxylin and eosin with at least 20% tumor nuclei.
Room temperature. Also acceptable: Refrigerated. Ship in cooled container during summer months.
Less than 10 percent tumor. Specimens fixed in any fixative other than 10 percent neutral buffered formalin. Decalcified specimens. FNA smears with less than 50 tumor cells.
Include surgical pathology report.
If multiple specimens (blocks or slides) are sent to ARUP, they must be accompanied by one of the following: an order comment indicating that the ARUP pathologist should choose the specimen most appropriate for testing (e.g., "Choose best block"), or individual orders for each sample submitted. A Pathologist Block Selection Fee (ARUP test code 3002076) will be added to orders that utilize the first option. If multiple specimens are sent to ARUP without a request for pathologist block/slide selection or individual orders, they will be held until clarification is provided.
Ambient: Indefinitely; Refrigerated: Indefinitely; Frozen: Unacceptable
Methodology
Massively Parallel Sequencing
Performed
Varies
Reported
10-12 days
Reference Interval
By report
Interpretive Data
Refer to report.
Laboratory Developed Test (LDT)
Note
A full list of the targeted genes and regions is listed in the Additional Technical Information.
Hotline History
Hotline History
CPT Codes
81272; 81314
Components
Component Test Code* | Component Chart Name | LOINC |
---|---|---|
2002148 | Block ID | 57723-9 |
2002673 | GIST Interpretation | 50398-7 |
Aliases
- c-KIT
- c-kit Mutation Analysis in Gastrointestinal Stromal Tumors (GISTs)
- CD117 KIT
- cKIT
- GIST
- GIST Mutation
- KIT
- KIT exons 9, 11, 13, 14, 17, and 18
- KIT mutation
- PDGFRA exons 12, 14 and 18
- PDGFRA Mutation in Gastrointestinal Stromal Tumors (GISTs)
- TKI resistance
- TKI sensitivity