Immunohistochemistry in Breast Pathology - Introduction
It cannot be emphasised enough that in most diagnostic situations immunohistochemistry is used
to support or refute a position taken on the appearance of the original H&E sections.
Immunohistochemistry is therefore used to answer very specific questions in the context of that particular H&E.
The examples below and on subsequent linked pages should be taken as illustrative rather than absolute.
This section has been subdivided by main heading to improve page download times. Supplementary material
(additional cases or images) are also provided on linked pages to relevant sections.
The principal functions of immunohistochemistry (IHC) in breast pathology are:
- Solving common diagnostic dilemmas
- Tumour typing and confirming diagnoses
- Analysis of prognostic markers e.g. ER
Solving common diagnostic dilemmas - Click to open page
- Benign/malignant e.g. Radial scar v Invasive cancer
- Epithelial proliferations e.g. Usual type hyperplasia v DCIS
- In situ v microinvasion
Tumour typing and confirming diagnoses - Click to open page
- Tumour typing e.g. Lobular v Ductal; Luminal v Basal/Myoepithelial
- Subtle foci of invasion
- Status of margins
- Lymph node metastases
- Demonstrating epithelial cells in necrotic material
Analysis of predictive markers - helping to assess prognosis and guide management
- Receptor studies- ER/PGR and Her2
- FISH testing for Her2 - not immuno but relevant
The most frequently used immunostains in breast pathology are:
- Myoepithelial markers - CK 5/6; P63
- Lobular v Ductal - E Cadherin
- Receptors - ER; PGR and Her2