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Immunohistochemistry (IHC)
Test Description
Epidermal Growth Factor Receptor (EGFR) is a 170 kDa transmembrane receptor tyrosine kinase that belongs to the HER/ErbB protein family. Somatic mutations in the tyrosine kinase domain of EGFR are present in a subset of lung adenocarcinomas. Two types of mutations account for approximately 90% of mutated cases: a specific point mutation, L858R, which occurs in exon 21 and short in-frame deletions in exon 19. A common lesion in exon 19 is the deletion of E746-A750, although other variants occur. IHC-based EGFR E746-A750del specific antibody is designed to detect deletion of E746-A750 in exon 19. Deletion in exon 19 is associated with response of non-small cell lung carcinoma (NSCLC) to gefitinib or erlotinib monotherapy.
Specimen Requirements
  • A formalin-fixed, paraffin-embedded (FFPE) tissue block is preferred specimen type
  • or
  • One (1) unbaked, unstained slide for H&E staining (required) and two to three (2-3) positively charged unstained slides (all cut at 4-5 microns) for each test/antibody ordered
  • Block and slide identifiers should be clearly written and match exactly with the specimen ID and specimen labeling as noted on the requisition.
Storage and Transportation
Use cold pack for transport. Make sure cold pack is not in direct contact with specimen.
CPT Code(s)*
88342 x 1 or 88341 x 1
Turnaround Time
Global: 48 hours, Tech-Only (stain only): 24 hours
New York Approved
Level of Service
Stain Only

*The CPT codes provided with our test descriptions are based on AMA guidelines and are for informational purposes only. Correct CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed.