February 28, 2023

AE1/AE3 are a pair of antibodies that recognize multiple cytokeratins, intermediate filament proteins found in epithelial cells. Cytokeratins are normally located in the cytoplasm (body) of the epithelial cell. Pathologists perform a test called immunohistochemistry to stain tissues for AE1/AE3 and the pattern and intensity of staining can help identify the presence of epithelial cells and differentiate them from non-epithelial cells. Staining for these markers is commonly used in pathology to aid in the diagnosis and classification of tumours of epithelial origin, including carcinomas.

In this image, the brown tumour cells are positive for AE1/AE3.

What tumours are positive for AE1/AE3?

Most noncancerous and cancerous tumours that start from epithelial cells are positive for AE1/AE3. Cancerous tumours made up of epithelial cells are called carcinomas and they can be found anywhere in the body. Subtypes of carcinoma including adenocarcinoma and squamous cell carcinoma are also positive for these markers. Staining for these markers helps pathologists distinguish carcinomas from other types of tumours that may look similar but do not make cytokeratins.

Are noncancerous tumours positive for AE1/AE3?

Yes. Many types of benign (noncancerous) tumours express cytokeratins and are positive for AE1/AE3. These types of noncancerous tumours are made up of epithelial cells that normally express cytokeratins.

About this article

Doctors wrote this article to assist you in reading and comprehending your pathology report. Feel free to contact us with any questions about this article or your pathology report. To get a comprehensive introduction to your pathology report, read this article.

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