Geisinger Medical Laboratories Test Catalog

Order Display Name: Geisinger Epic Procedure Code Or ID CPT Code:  


Geisinger Epic Procedure Code: LAB2205             Geisinger Epic ID: 43012

Specimen type:
Formalin-fixed, paraffin embedded block (FFPE)
Specimen required:
Two (2) 10 micron sections in 50 mL tube (preferred),with contiguous H&E (cut last), four (4) 10 micron FFPE unstained slides with H&E or paraffin block.
Special notes:
For requests from non-Geisinger sites, please send: Five (5) 10 micron FFPE sections (scrolls)- preferred specimen, H&E slide, source of specimen, and tumor assessment (<10% or >10%). Alternatively, send FFPE block. Isolated/extracted nucleic acids are acceptable only from CLIA-certified laboratories or a laboratory meeting equivalent requirements as determined by CAP and/or CMS.

Transport temperature:
Room temperature (18-25°C).
Specimen stability:
Rejection criteria:
Blocks containing no tumor (evaluated by pathologist) will be rejected. FFPE tissues that have been decalcified. Insufficient DNA.

Reference interval:
Negative for mutation(s) tested.
CPT code(s):
Note: The billing party has sole responsibility for CPT coding.  Any questions regarding coding should be directed to the payer being billed.  The CPT codes provided by GML are based on AMA guidelines and are for informational purposes only.
Test includes:
Identification of 51 EGFR mutations in exons 18, 19 (exon 19 deletions), 20 and 21.
Real-time Polymerase Chain Reaction (PCR)
EGFR, EGFRMU, Epidermal Growth Factor Receptor
Clinical significance:
Testing for EGFR mutations is used to predict response to tyrosine kinase inhibitor (TKI) therapy or plan alternate treatment. Activating EGFR mutations which are associated with increased sensitivity to EGFR TKIs predominate in never-smokers, females, and tumors with histological features typical of adenocarcinomas. However, mutation testing is much more effective for predicting which patients might benefit from targeted TKI therapies. The prevalence of EGFR mutations in Asians and Caucasians is 40% and 10-15%, respectively. There is a significant association between sensitivity to EGFR TKIs and EGFR mutations, especially exon 19 deletions (~50% of EGFR mutations) and L858R point mutation in exon 21 (~35-45% of EGFR mutations). L861Q and G719X in exons 18-21 account for most of the remaining common mutations. Other mutations such as the T790M point mutation are associated with secondary resistance to TKIs.
Doctoral Director(s:)
Yi Ding MD, PhD    
Review Date: 12/20/2022

Performing Locations

Geisinger Medical Center

Performing laboratory: Molecular Diagnostics
Technical Lead: Ronnie Rovenolt, Becky Knock
Frequency: Daily, Monday-Friday
Performed STAT? No
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