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Test Code H2TOF HER2 FISH, Tech Only

Important Note

Fill out Cytogenetics Tech Only HER2 Paraffin Testing Patient Information form under Resources

Additional Codes

*Test is only orderable by Rice Memorial Hospital Laboratory staff

Testing Algorithm

FISH testing for HER2 amplification is performed using the chromosome 17 centromere probe (D17Z1) as the control. The client is responsible for the interpretation and billing of the professional component; Mayo Medical Laboratories will bill the technical component only.

 

This test will be automatically cancelled and complete HER2 FISH testing with an interpretation will be performed and charged if:

1. A tumor block is received

2. An unmarked hematoxylin and eosin-stained slide is submitted

3. The HER2/D17Z1 ratio or average number of HER2 signals falls in the equivocal range, as defined by 2013 American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guidelines. Additional testing using the HER2/D17S122 probe will be performed and interpreted.
4. HER2 tumor heterogeneity (as defined by ASCO/CAP) is identified
5. No HER2 amplification is observed in the area marked by the submitting pathologist but HER2 amplification is detected in an area of invasive tumor outside the scribed area.

Note: HER2 testing for other tumor types include:

-FHER2 / HER2 Amplification Associated with Breast Cancer, FISH, Tissue

-FH2UR / HER2 Amplification Associated with Urothelial Carcinoma, FISH, Tissue

-FH2GE / HER2 Amplification Associated with Gastroesophageal Cancer, FISH, Tissue

-FH2MT / HER2 Amplification, Miscellaneous Tumor, FISH, Tissue

Methodology

The test is performed using the PathVysion HER2 DNA probe set (Abbott Molecular) with a HER2 probe and a chromosome 17 centromere probe (D17Z1). Using the hematoxylin and eosin-stained slide marked with the invasive tumor area by the client, targeted areas are etched with a diamond-tipped etcher on the back of the unstained slide to be assayed. The probe is hybridized to the tissue and 2 technologists each analyze 30 interphase nuclei (60 total). The entire slide is scanned to identify areas of amplification outside the marked area; if present, a Mayo Clinic pathologist will review the case. The average number of HER2 and D17Z1 signals per cell and the ratio of HER2 signals as compared to D17Z1 signals is provided to client. Reflex testing is performed using a laboratory developed HER2/D17S122 probe.(Unpublished Mayo method)

Performing Laboratory

Mayo Medical Laboratory performs HER2 FISH

Rice Hospital Lab pathologist performs interpertation

Specimen Requirements

The tumor samples submitted should have been fixed in formalin for >6 hours and <72 hours. Provide a pathology report with each sample. A delay in reporting will occur if reflex testing is necessary and a pathology report is not provided.

 

Specimen Type: Slides

Specimen Volume: 4 consecutive, unstained, 5-micron thick sections placed on positively charged slides and 1 hematoxylin and eosin (H and E)-stained slide with the area of invasive tumor marked

Collection Instructions: If the tumor block or an unmarked H and E-stained slide is submitted, the test will be automatically cancelled and appropriate tumor type HER2 FISH test (including analysis and interpretation) will be performed and charged.

Specimen Transport Temperature

Ambient(preferred)/Refrigerated

Reference Values

Not applicable

Day(s) Test Set Up

Samples processed Monday through Sunday. Results released Monday through Friday, 8 a.m.-5 p.m. CST.

CPT Coding

88377 TC