Overview: CD117 Immunohistochemistry TestIntroduction: The CD117 Immunohistochemistry Test detects CD117 protein to diagnose gastrointestinal stromal tumors (GIST), causing abdominal pain. Aligned with 2023 NCCN guidelines, it uses immunohistochemistry for high specificity, supporting cancer screening. This test is critical for guiding diagnosis, treatment planning, and improving outcomes in histopathology for patients with suspected GIST.
Other Names: CD117 IHC Assay, c-KIT IHC Test.
FDA Status: Laboratory-developed test (LDT), meeting histopathology standards for diagnostic accuracy.
Historical Milestone: CD117 testing began in the 1990s with GIST research. Immunohistochemistry-based methods improved in the 2000s, enhancing diagnostic precision.
Purpose: Detects CD117 to diagnose GIST, guides treatment, and evaluates patients with abdominal pain.
Test Parameters: 1. CD117 Protein
Pretest Condition: No fasting required. Collect tissue via biopsy or surgical resection. Report history of abdominal pain, bleeding, or GI symptoms.
Specimen: 0.5-2 cma³ tissue (FFPE). Transport in a biohazard container.
Sample Stability at Room Temperature: 7 days
Sample Stability at Refrigeration: Not refrigerated
Sample Stability at Frozen: Not frozen
Medical History: Document abdominal pain, GI bleeding, or family history of GIST. Include current medications, especially tyrosine kinase inhibitors.
Consent: Written consent required, detailing the tests purpose, cancer implications, and risks of biopsy or surgery.
Procedural Considerations: Uses immunohistochemistry to detect CD117 in GI tissue. Results are available in 1-2 days, supporting rapid clinical decisions. Performed in laboratories, often for GIST diagnosis.
Factors Affecting Result Accuracy: Improper tissue fixation or processing can affect results. Low tissue quality may reduce staining accuracy.
Clinical Significance: Positive CD117 staining confirms GIST, guiding imatinib or surgical therapy. Negative staining may require further tumor marker testing.
Specialist Consultation: Consult an oncologist or gastroenterologist for result interpretation and treatment planning.
Additional Supporting Tests: DOG1 IHC, KIT mutation testing, or abdominal CT to confirm GIST diagnosis.
Test Limitations: Not specific to GIST; other tumors may express CD117. Clinical correlation is needed.
References: NCCN GIST Guidelines, 2023; American Journal of Surgical Pathology, Rubin BP, 2022.
