ERBB2 (HER2/neu) Gene Amplification by FISH with Reflex, Tissue
Ordering Recommendation

Aid in prediction of response to HER2-directed therapy in patients with breast carcinoma or gastroesophageal adenocarcinoma. Use to confirm equivocal HercepTest (2+) immunohistochemistry (IHC) result.

Fluorescence in situ Hybridization
3-9 days
New York DOH Approval Status
This test is New York DOH approved.
Submit With Order
ARUP Consult®
Disease Topics
Specimen Required
Patient Preparation
Tumor tissue. 
Specimen Preparation
Formalin fix (10 percent neutral buffered formalin) and paraffin-embed tissue. Fixative duration: 6-72 hours.  Protect paraffin block from excessive heat. Transport block or 7 unstained (4 micron thick sections) positively charged slides in a tissue transport kit (ARUP supply #47808) available online through eSupply using ARUP Connect™ or contact ARUP Client Services at (800) 522-2787 (kit recommended but not necessary). (Min 4 slides) 
Storage/Transport Temperature
Room temperature. Also acceptable: Refrigerated. Ship in cooled container during summer months. 
Unacceptable Conditions
Specimens fixed or processed in alternative fixatives (alcohol, Prefer) or heavy metal fixatives (B-4 or B-5). No tumor in tissue. Decalcified specimens.  Tissue fixed for less than 6 hours or greater than 72 hours. 
Include surgical pathology report. 
Ambient: Indefinitely; Refrigerated: Indefinitely; Frozen: Unacceptable 
Reference Interval
Interpretive Data
Refer to report. ARUP uses the most recent ASCO/CAP interpretation criteria for evaluating ERBB2 (HER2) status.

Breast tissue results of FISH group 2, 3, or 4 will be reflexed to ERBB2 (HER2/neu) (HercepTest) with Interpretation by Immunohistochemistry, Tissue (ARUP test code 0049174). Additional charges apply. Gastric and other non-breast tissue with indeterminate results will be reflexed to an alternate probe in an effort to resolve amplification status. Additional charges apply.
Hotline History
View Hotline History
CPT Code(s)
88377, if reflexed add 88360 or 88377
Component Test Code*Component Chart NameLOINC
0049241ERBB2 (HER2) by FISH42783-1
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please view this test within the Laboratory Test Directory found at
  • c-erbB2 FISH
  • CEP17
  • HER-2/neu FISH
  • Her-2/neu Gene Amplification or Overexpression
  • HER2/CEP17 Ratio
  • PathVysion FISH