KIT Gene Immunohistochemistry (IHC)
Notes
**Note 1:** Physician statement of KIT IHC can be used to code this data item when no other information is available. **Note 2:** KIT Gene Immunohistochemistry (IHC) is the expression of the KIT gene in tumor tissue specimens based on immunohistochemical (IHC) stains. A positive test is a diagnostic and predictive marker for GIST tumors. Do not record secondary or acquired mutations that may have developed because of long-term imatinib treatment. **Note 3:** Other names for KIT are CD117 or c-kit. **Note 4:** Results from nodal or metastatic tissue may be used for KIT Gene Immunohistochemistry.| Code | Description |
|---|---|
| 0 | KIT negative/normal; within normal limits |
| 1 | KIT positive |
| 7 | Test ordered, results not in chart |
| 8 | Not applicable: Information not collected for this case (If this information is required by your standard setter, use of code 8 may result in an edit error.) |
| 9 | Not documented in medical record Cannot be determined by pathologist KIT not assessed or unknown if assessed |