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UW Health SMPH
American Family Children's Hospital

UW Hospital and Clinics Lab Test Directory

Test Name: HER2 Dual ISH DNA

Test Code(s): PATHS / HCPATHS

CPT Code(s): 88368X2

Methodology: Dual In situ Hybridization (ISH)

Days Performed: Mon-Fri.

Turnaround Time: Routine: 7 days.


Specimen Requirements

Specimen: Formalin-fixed, paraffin embedded tissue from breast origin.

Collection Instructions: Tissue specimens should be immersed in fixative within one hour of the biopsy or resection procedure.  Specimens must be fixed in 10% neutral buffered formalin for 6-48 hours.  The volume of formalin should be at least 10 times the volume of the specimen.

Specimen Processing: FFPE tissue containing tumor should be cut in 4-micron sections on slide.

Specimen Transport: Transport in formalin at room temperature.

Unacceptable Criteria: Specimens processed in alternative fixatives or with alternative fixative durations.  Decalcification solutions with strong acids should not be used.

Stability: Ambient: Indefinitely
Refrigerated: Indefinitely
Frozen: Not acceptable


Interpretation

Non-amplified (HER2/Chr17 ratio less than 2.0)

Test Limitations:

Tissue staining is dependent on the handling and processing of the tissue prior to staining. Improper fixation, freezing, thawing, washing, drying heating, sectioning or contamination with other tissues or fluids may produce artifacts. Inconsistent results may be a consequence of variations in fixation and embedding methods or inherent irregularities within the tissue.

 

The clinical interpretation of any positive staining, or its absence, must be evaluated within the context of clinical history, morphology and other histopathological criteria.

Additional Information:

UWHC Policies 7.01 Pathology Specimen Care and Handling and 8.27 Requesting Consultations from Surgical Pathology Lab describe the requirements for submission, identification, handling and release of tissue specimens including exemptions and guidelines for limited examination.

 

Interpretation provided as an addendum to original pathology report located in the Health Link Path tab.

 

Report Results

Non-Amplified HER2/Chr17

< 2.0

Amplified HER2/Chr17

≥ 2.0

 

 

 

 

 

Specimens with equivocal HER2/Chr17 ratios and decalcified tissues will be reflexed for Her2/neu immunohistochemistry staining.

 

The presence of HER2 gene amplification predicts a favorable response to trastuzumab.

Her2/neu, HER-2

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