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HER2/ERBB2 FISH (8000100485)
Test Mnemonic:


Specimen Requirements:

 Formalin fixed (10 percent neutral buffered formalin, fixed within 6-48 hours) and paraffin embedded tissue sections (prepared in Surgical Pathology or Cytopathology), mounted on +ve charge slides.  Transport 2 unstained 5 micron slides (Minimum is 3 slides) with a matching HE slide marked tumor area for FISH testing.


Slide preparations


Protect specimens from excessive heat. Ship in cooled container during summer months. Room temperature or refrigerated.



Causes for Rejection:

Incomplete and/or incorrect specimen identification. Sections not mounted on +ve charge slides.

Reference Range:

Reported as  HER2/ERBB2 copy-number relative to chromosome 17 centromere (CEP17) ratio based on the following guidelines:

If HER2.ERBB2:CEP17 ratio is >2.0, HER2/ERBB2 amplification was observed.

If HER2/ERBB2:CEP17 ratio is <2, and

1. Average HER2/ERBB2 copy number is >6.0 signals/cell, HER2/ERBB2 amplification is observed:

2. Average HER2/ERBB2 copy number is <4.0 signals/cell, HER2/ERBB2 gene amplification is not observed;

3. Average HER2/ERbb2 copy number is >4.0 and <6.0 signals/cell, result is equivocal.


Turnaround Time:

7 days


Fluorescent in situ hybridization (FISH)


Molecular Diagnostics Laboratory (Telephone 409-772-4197)


HER2 neu DNA test; HER2/ERBB2 gene amplification

Clinical Indication:

Used as a predictive and prognostic tumor marker


Patient Preparation :

Tumor sample

CPT 4 Code:



This test is usually ordered by a pathologist after review of HER2 IHC result.

When ordering tests for which Medicare or Medicaid reimbursement will be sought, physicians should only order tests that are medically necessary for the diagnosis or treatment of the patient. Components of the organ or disease panels may be ordered individually. The diagnostic information must substantiate all tests ordered and must be in the form of an ICD-10 code or its verbal equivalent.
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