What does this LOINC code represent?

This LOINC code identifies a lab observation, measurement, question, or clinical concept in a standardized format.

Is this enough to understand my test result?

No. The code identifies the test or observation, but the interpretation depends on the actual result, reference range, and clinical context.

LOINCActiveObservation

LOINC Code 74860-8: ERBB2 copy number/nucleus FISH (Tiss) [Entitic number]

Name: LOINC Code 74860-8: ERBB2 copy number/nucleus FISH (Tiss) [Entitic number]
Creator: HealthAssure Clinical Team
Published: 2026-05-21T08:59:55.156Z

74860-8 is a LOINC code used to identify ERBB2 copy number/nucleus FISH (Tiss) [Entitic number] in laboratory and clinical observation data. You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges. LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component ERBB2 gene copy number/nucleus. It is commonly used with the system or sample type Tiss.

Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026

What is this code?

LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component ERBB2 gene copy number/nucleus. It is commonly used with the system or sample type Tiss.

When is it used?

Used in lab systems, EHRs, and clinical data exchange.
May identify a test, observation, survey item, or clinical document request rather than a diagnosis.
Status: ACTIVE
Order vs observation: Observation
Method: FISH

What it does not mean

The code identifies the observation or test, not the actual result.

Key facts

ERBB2 gene copy number/nucleus in Tissue by FISH

ERBB2 gene copy number/nucleus

The average number of fluorescent signals targeting the ERBB2 gene (HER2 locus) in nuclei are determined in order to calculate the average ratio of ERBB2 gene to Chromosome 17 copy number [LOINC49683-6]. This term is based on, but not limited in use to, the PathVysion HER-2 DNA Probe Kit, which detects amplification of the ERBB2 gene via fluorescence in situ hybridization (FISH) in formalin-fixed, paraffin-embedded human breast and gastric cancer tissue specimens. The kit contains two probes: one specific to the HER-2/neu gene locus (ERBB2 gene, 17q11.2-q12) and another targeting the alpha satellite DNA sequence at the centromeric region of chromosome 17 (17p11.1-q11.1), called CEP17 (Chromosome Enumeration Probe 17). The average number of HER2 signals along with CEP17 signals [LOINC: 74861-6] are determined by microscopic examination within the same set of nuclei. The specimen is positive for ERBB2 gene amplification if the mean ratio of HER2 to CEP17 signals per nucleus is greater than or equal to 2.00.

breast cancer; CD340; c-erb B2; Entitic; Entitic number; ErbB-2; ERBB2 copy num; erb-b2 receptor tyrosine kinase 2; Fluorescent in situ hybridization; Genetics; HER2; HER-2; HER2/neu; HER-2/neu; Heredity; Heritable; Inherited; MLN 19; Molecular pathology; MOLPATH; NEU; NGL; No; Num; p185; Point in time; QNT; Quan; Quant; Quantitative; Random; Tissue; Tissue, unspecified; TKR1; v-erb-b2 avian erythroblastic leukemia viral oncogene homolog 2 (neuro/glioblastoma derived oncogene homolog)

Where you may see this code

You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges.

Common synonyms

ERBB2 copy number/nucleus FISH (Tiss) [Entitic number]ERBB2 gene copy number/nucleus in Tissue by FISHERBB2 copy num/nucleus EntNum Tiss FISHERBB2 gene copy number/nucleusMOLPATHERBB2 copy number/nucleus, TissueEntNum

Frequently asked questions

Code details

Code74860-8

SystemLOINC

Display nameERBB2 copy number/nucleus FISH (Tiss) [Entitic number]

DescriptionERBB2 gene copy number/nucleus

Short nameERBB2 copy num/nucleus EntNum Tiss FISH

ComponentERBB2 gene copy number/nucleus

PropertyEntNum

TimingPt

System (specimen)Tiss

ScaleQn

MethodFISH

ClassMOLPATH

Example units#

StatusACTIVE

Order/ObservationObservation

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.48

Last changed2.73

Consumer names

ERBB2 copy number/nucleus, Tissue

Part names

ERBB2 gene copy number/nucleusEntNumPtTissQnFISHEntitic numberPoint in time (spot)Tissue and SmearsFluorescent in situ hybridization (FISH)

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from LOINC. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.