Overview: Epithelial Membrane Antigen Immunohistochemistry TestIntroduction: The Epithelial Membrane Antigen Immunohistochemistry Test detects EMA to diagnose epithelial tumors, causing lumps or pain. 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 epithelial malignancies, such as carcinomas.
Other Names: EMA IHC Assay, Epithelial Tumor IHC Test.
FDA Status: Laboratory-developed test (LDT), meeting histopathology standards for diagnostic accuracy.
Historical Milestone: EMA testing began in the 1980s with carcinoma research. Immunohistochemistry-based methods improved in the 2000s, enhancing diagnostic precision.
Purpose: Detects EMA to diagnose epithelial tumors, guides treatment, and evaluates patients with lumps or pain.
Test Parameters: 1. Epithelial Membrane Antigen
Pretest Condition: No fasting required. Collect tissue via biopsy or surgical resection. Report history of lumps, pain, or suspected carcinoma.
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 lumps, pain, weight loss, or family history of carcinomas. 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 EMA in tissue. Results are available in 1-2 days, supporting rapid clinical decisions. Performed in laboratories, often for carcinoma diagnosis.
Factors Affecting Result Accuracy: Improper tissue fixation or processing can affect results. Low tissue quality may reduce staining accuracy.
Clinical Significance: Positive EMA staining confirms epithelial tumors (e.g., adenocarcinoma), guiding surgery or chemotherapy. Negative staining may suggest non-epithelial tumors.
Specialist Consultation: Consult an oncologist for result interpretation and treatment planning.
Additional Supporting Tests: Pancytokeratin IHC, CK7 IHC, or imaging (e.g., CT/MRI) to confirm epithelial tumor diagnosis.
Test Limitations: Not specific to one carcinoma type; some sarcomas may express EMA. Clinical correlation is needed.
References: WHO Tumor Classification Guidelines, 2023; American Journal of Surgical Pathology, Miettinen M, 2022.
