Epithelial cells are a specialized type of cell that form a thin tissue barrier called an epithelium. This barrier can be on the surface or on the inside of a tissue. There are many different types of epithelial cells found throughout the body.
Types of epithelial cells include:
Many different types of cancer can start from epithelial cells. All cancers in this group are called carcinomas. These cancers can start in any area of the body where epithelial cells are normally found.
Types of cancer that start from the cells in the epithelium include:
Sometimes the abnormal epithelial cells are seen only inside the epithelium, Pathologists call this condition dysplasia. Carcinoma in situ is a diagnosis pathologists use to describe epithelial cells that look the same as cancer cells but are still seen only in the epithelium. Carcinoma in situ is called a non-invasive type of cancer because the abnormal epithelial cells have not spread to the tissue below the epithelium. The movement of abnormal epithelial cells out of the epithelium and into the tissue below is called invasion.