November 5, 2023

CDX-2 is a type of protein called a transcription factor. It helps guide the expression of genes required for the normal development of a cell and it is usually produced by cells in the small intestine and colon. Tissues that have undergone a noncancerous process called intestinal metaplasia will also make this protein. Most benign (noncancerous) and malignant (cancerous) tumours that arise from these organs will also produce CDX-2.

Immunohistochemistry (IHC) is a test pathologists perform to see CDX-2-producing cells in a tissue sample. When combined with other immunohistochemical markers, this test allows pathologists to determine if the cells they are seeing under the microscope come from one of the organ systems that normally produces this protein. Cells that produce CDX-2 are typically described as ‘positive’ while those that do not produce the protein are described as ‘negative’.

This test is particularly helpful when examining a tumour under the microscope because tumours that come from the small intestine and colon are more likely to produce CDX-2 while tumours from other locations are not. Pathologists use the results of this test combined with other features to make a diagnosis.

Examples of tumours that are positive for CDX-2:

About this article

This article was written by doctors to help you read and understand your pathology report. Contact us if you have questions about this article or your pathology report. For a complete introduction to your pathology report, read this article.

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