Pathology dictionary -
Squamous cell carcinoma
Squamous cell carcinoma is a type of cancer (a malignant tumour) made up of squamous cells. Squamous cell carcinoma can start any where in the body although in it most common in locations where squamous cells are normally found such as the skin, inside of the mouth, lungs, and cervix.
Squamous cells are a special type of cell that are normally found on the surface of a tissue. The squamous cells create a barrier which protects the tissue below the surface from infections and injuries. Squamous cell can be found on the outer surface of a tissue such as the skin or the inner surface of a tissue such as the esophagus.
Squamous cell carcinoma is a very common type of cancer (malignant tumour). It often develops from a pre-cancerous disease called squamous carcinoma in situ.
Some common locations for squamous cell carcinoma include:
What causes squamous cell carcinoma?
The cause depends on the location in the body where the tumour starts. Chemicals, especially those found in cigarette smoke, are associated with the development of squamous cell carcinoma in the tongue, esophagus, larynx, and lungs.
A virus called human papillomavirus infects cells in the tonsils and cervix and is the cause for almost all cases of squamous cell carcinoma in these locations.
Ultraviolet light from the sun causes most cases of squamous cell carcinoma in the skin.
Keratinizing and non-keratinizing tumours
Squamous cell carcinoma can also be described as keratinizing if the tumour produces a special type of protein called keratin which is normally found on the surface of the skin. Tumours that do not produce keratin are called non-keratinizing squamous cell carcinoma.