Overview: CD99 MIC2 Immunohistochemistry TestIntroduction: The CD99 MIC2 Immunohistochemistry Test detects CD99 protein to diagnose Ewing sarcoma or lymphomas, causing bone pain or swelling. Following 2023 WHO 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 Ewing sarcoma or lymphomas.
Other Names: CD99 IHC Assay, Ewing Sarcoma IHC Test.
FDA Status: Laboratory-developed test (LDT), meeting histopathology standards for diagnostic accuracy.
Historical Milestone: CD99 testing began in the 1990s with Ewing sarcoma research. Immunohistochemistry-based methods improved in the 2000s, enhancing diagnostic precision.
Purpose: Detects CD99 to diagnose Ewing sarcoma or lymphomas, guides treatment, and evaluates patients with bone pain or swelling.
Test Parameters: 1. CD99 Protein
Pretest Condition: No fasting required. Collect tissue via biopsy or surgical resection. Report history of bone pain, swelling, or lymphoma 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 bone pain, swelling, masses, or family history of sarcomas or lymphomas. Include current medications, especially chemotherapy.
Consent: Written consent required, detailing the tests purpose, cancer implications, and risks of biopsy or surgery.
Procedural Considerations: Uses immunohistochemistry to detect CD99 in tissue. Results are available in 1-2 days, supporting rapid clinical decisions. Performed in laboratories, often for Ewing sarcoma or lymphoma diagnosis.
Factors Affecting Result Accuracy: Improper tissue fixation or processing can affect results. Low tissue quality may reduce staining accuracy.
Clinical Significance: Positive CD99 staining suggests Ewing sarcoma or certain lymphomas, guiding chemotherapy or surgery. Negative staining may require further marker testing.
Specialist Consultation: Consult an oncologist or orthopedic oncologist for result interpretation and treatment planning.
Additional Supporting Tests: EWSR1 FISH, FLI1 IHC, or bone scan to confirm Ewing sarcoma diagnosis.
Test Limitations: Not specific to Ewing sarcoma; other tumors may express CD99. Clinical correlation is needed.
References: WHO Sarcoma Guidelines, 2023; American Journal of Surgical Pathology, Folpe AL, 2022.
