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Test ID: KIT8 KIT Exon 8, Mutation Analysis

Useful For

Diagnosis and management of patients with gastrointestinal stromal tumors or other related tumors


Identification of a mutation in exon 8 of the KIT gene

Additional Tests

Test ID Reporting Name Available Separately Always Performed
SLIRV Slide Review in MG No, (Bill Only) Yes

Testing Algorithm

This test is performed in conjunction with SLIRV / Slide Review in MG. Additional testing may be performed after review by pathologist. Upon approval from the requesting clinician, PATHC / Pathology Consultation may be added, if determined to be appropriate.

Special Instructions

Method Name

Polymerase Chain Reaction (PCR) and Sequencing

Reporting Name

KIT exon 8, Mutation Analysis

Specimen Type


Advisory Information

Special stains performed outside Mayo Clinic Laboratories and included with the case may be repeated and charged at the reviewing pathologist's discretion. Testing requested by referring physician may not be performed if deemed unnecessary by Mayo Clinic pathologist.

Necessary Information

A pathology/diagnostic report including a brief history is required. If available, include KIT Immunostain results.

Specimen Required

A quality specimen is essential for evaluation. Submit only tissue containing tumor cells; minimal tissue is required for evaluation.


Supplies: Surgical Pathology Packaging Kit (T554) requested, but not required



Specimen Type: Formalin fixed, paraffin-embedded (FFPE) tissue block with a minimum of 60% tumor cell population

Collection Instructions: Process all specimens into FFPE tissue blocks prior to submission.



Specimen Type: Unstained slides with a minimum of 60% tumor population; slides may be stained and/or scraped

Slides: A minimum of ten, 4- to 5-micron thick, unstained slides are required.

Specimen Stability Information

Specimen Type Temperature Time
Varies Ambient (preferred)

Clinical Information

Several tumors can harbor KIT mutations, including gastrointestinal stromal tumors (GIST), mast cell disease, melanoma, seminoma, acute myeloid leukemia, myeloproliferative neoplasms, and lymphomas. The frequency and type of mutations vary among these tumors and portent distinct clinical implications. The ordering physician is responsible for the diagnosis and management of disease and decisions based on the data provided.

Reference Values

An interpretative report will be provided.


Results are reported as positive, negative, or failed. A negative result does not rule out the presence of a mutation.

Clinical Reference

1. Robson ME, Glogowski E, Sommer G, et al: Pleomorphic characteristics of a germ-line KIT mutation in a large kindred with gastrointestinal stromal tumors, hyperpigmentation, and dysphagia. Clin Cancer Res 2004;10:1250-1254

2. Li FP, Fletcher JA, Heinrich MC, et al: Familial gastrointestinal stromal tumor syndrome: phenotypic and molecular features in a kindred. J Clin Oncol 2005;23:2735-2743

3. Corless CL, Fletcher JA, Heinrich MC: Biology of gastrointestinal stromal tumors. J Clin Oncol 2004;22:3813-3825 

4. Debiec-Rychter M, Raf Sciot R, Le Cesne A, et al: KIT mutations and dose selection for imatinib in patients with advanced gastrointestinal stromal tumors. Eur J Cancer 2006;42:1093-1103 

5. Heinrich MC, Corless CL, Demetri GD, et al: Kinase mutations and imatinib mesylate response in patients with metastatic gastrointestinal stromal tumor. J Clin Onc 2003;21:4342-4349 

6. Debiec-Rychter M, Dumez H, Judson I, et al: Use of c-KIT/PDGFRA mutational analysis to predict the clinical response to imatinib in patients with advanced gastrointestinal stromal tumors entered on phase I and II studies of the EORTC Soft Tissue and Bone Sarcoma Group. Eur J Cancer 2004;40:689-695

Day(s) and Time(s) Performed

Monday through Friday; Varies

Analytic Time

14 days

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

81272-KIT (v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog) (eg, gastrointestinal stromal tumor [GIST], acute myeloid leukemia, melanoma), gene analysis, targeted sequence analysis (eg, exons 8, 11, 13, 17, 18)

88381-Microdissection, manual

LOINC Code Information

Test ID Test Order Name Order LOINC Value
KIT8 KIT exon 8, Mutation Analysis 87733-2


Result ID Test Result Name Result LOINC Value
54790 Result Summary 50397-9
54791 Result 82939-0
54792 Interpretation 69047-9
54793 Additional Information 48767-8
54794 Reason for Referral 42349-1
54795 Specimen 31208-2
54796 Source 31208-2
54797 Tissue ID 80398-1
54798 Released By 18771-6


1. Pathology/Cytology Information (T707) in Special Instructions

2. If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

-Pathology Test Request (T246)

-Oncology Test Request (T729)

Mayo Clinic Laboratories | Oncology Catalog Additional Information:

mml-bone-soft-tissue-cancer, mml-gastrointestinal-cancer