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Test Code HERGM HER2, Gastric/Esophageal, Semi-Quantitative Immunohistochemistry, Manual

Advisory Information

If being ordered for diagnostic purposes: order PATHC / Pathology Consultation and then request the stains.


For breast cancer specimens, order HERBA / HER2, Breast, Quantitative Immunohistochemistry, Automated with HER2 FISH Reflex or HERBN / HER2, Breast, Quantitative Immunohistochemistry, Automated, No Reflex

Shipping Instructions

Attach the green pathology address label included in the kit to the outside of the transport container.

Necessary Information

Include accompanying pathology report stating the final diagnosis. If not available, a preliminary diagnosis is acceptable only if it refers to invasive or metastatic gastric or esophageal adenocarcinoma.

Specimen Required

Only paraffin-embedded (FFPE) gastric or esophageal adenocarcinoma specimens will be accepted. Fixation in 10% neutral-buffered formalin is preferred. The performance and quality of immunohistochemical stains in 10% neutral-buffered FFPE tissue depends on proper fixation. It is recommended (not required) for surgical specimens to be fixed between 18 and 24 hours and biopsy specimens between 6 and 8 hours.


If being ordered for prognostic purposes:

Specimen Type:

Supplies: Pathology Packaging Kit (T554)

Preferred: Paraffin-embedded tissue block containing invasive gastric or esophageal adenocarcinoma tissue

Collection Instructions: Tissue must have been fixed in 10% neutral-buffered formalin shipped at ambient temperature.


Acceptable: Slides

Specimen Volume: 5

Collection Instructions:

1. 5 unstained sections, containing gastric or esophageal adenocarcinoma, on charged slides cut at 4 microns <1 month ago and shipped at ambient temperature.

2. Tissue on the slides should be fixed in 10% neutral-buffered formalin.

Additional Information: Paraffin blocks will be returned with final report.


If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

Pathology Test Request Form (T246) (

Oncology Test Request Form (T729) (

Immunohistochemical (IHC)/In Situ Hybridization (ISH) Stains Request Form (T763) (

Useful For

Determining overexpression of HER2 protein of gastric and esophageal adenocarcinoma in formalin-fixed, paraffin-embedded tissue sections (with reflex to FISH testing)

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
H2GEF HER2, Gastroesophageal FISH, Ts Yes No

Testing Algorithm

Cases that are equivocal (2+) by immunohistochemical stain will reflex to HER2 amplification by FISH at an additional charge.

Method Name

Ventana Pathway Immunoperoxidase Stain with Manual Semi-Quantitative Immunohistochemistry

Reporting Name

HER Gastric/Esoph IHC + Reflex

Specimen Type


Specimen Stability Information

Specimen Type Temperature Time
Special Ambient (preferred)

Reject Due To









Reference Values

Reported as negative (0, 1+), equivocal (2+), and positive (3+)

Day(s) and Time(s) Performed

Monday through Friday

Analytic Time

2 days (HER2 IHC only); 8 days (if H2GEF is added on)

Performing Laboratory

Mayo Medical Laboratories in Rochester

Test Classification

This test has been cleared or approved by the U.S. Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
HERGM HER Gastric/Esoph IHC + Reflex In Process


Result ID Test Result Name Result LOINC Value
70985 Interpretation 50595-8
70986 Participated in the Interpretation No LOINC Needed
70987 Report electronically signed by In Process
70989 Material Received 81178-6
MA019 Tumor classification In Process
71625 Disclaimer 62364-5
71839 Case Number In Process