Cytokeratins

Pathology dictionary

What are cytokeratins?

Cytokeratins are a group of proteins called intermediate filaments that are normally found inside specialized epithelial cells. Cytokeratins provide structural support and help maintain the integrity of the cell.

What types of cells normally produce cytokeratins?

Cytokeratins are primarily produced by epithelial cells, which make up the lining of many internal and external surfaces of the body, such as the skin, organs, and glands. These cells use cytokeratins to provide structural support and protect against mechanical stress, as well as to help maintain their shape and function. While cytokeratins are not specific to any one type of epithelial cell, different types of epithelial cells may produce different types of cytokeratins, which can be used to identify and classify these cells. For example, epithelial cells in the colon typically express cytokeratin-20 (CK20) while the epithelial cells in the stomach express cytokeratin-7 (CK7).

What types of tumours express cytokeratins?

Cytokeratins are commonly expressed in many types of tumours that start from epithelial cells including a group of cancers called carcinomas. Examples of carcinomas that produce cytokeratins include breast cancer, lung cancer, pancreatic cancer, prostate cancer, and colorectal cancer, among others. However, it’s important to note that not all epithelial tumors express cytokeratins, and the specific pattern of cytokeratin expression can vary depending on the type of cancer. Some non-epithelial tumours can also express cytokeratins.

Why do pathologists test for cytokeratins?

Cytokeratins are commonly used as markers to identify and classify different types of epithelial cells, and they play a key role in the diagnosis and classification of many types of cancer.

How do pathologists test for cytokeratins?

Pathologists perform a test called immunohistochemistry (IHC) to look for cytokeratins inside a tissue sample.

cytokeratins
This picture shows tumour cells expressing cytokeratins.

What does positive for cytokeratins mean?

Positive for cytokeratins means that the cells in the tissue sample express cytokeratins.

What does negative for cytokeratins mean?

Negative for cytokeratins means that the cells in the tissue sample do not express cytokeratins.

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