Definition
The term squamous cell carcinoma describes a form of malignant skin cancer that originates from the superficial skin cells. It occurs particularly frequently in places that are exposed to UV radiation for long periods of time or are subject to permanent mechanical irritation. However, the carcinoma can theoretically be located at all sites that are structured as squamous epithelium.
This includes the entire skin surface as well as the mucous membrane in the mouth and in the genital region. A squamous cell carcinoma initially looks inconspicuous: It usually appears as a grayish yellowish coating on the skin, which may be covered with cornea. In the course of time, squamous cell carcinoma often develops into a wartlike outwardly growing growth or a permanently sore, flat spot.
The causes
The most common cause for the development of squamous cell carcinoma is UV radiation, i.e. sun exposure. A further, but less frequently occurring risk factor is known to be constant skin irritation. Both of these factors cause skin damage, and the body can fail in the long term to repair them.
As a result, tumor cells can develop at these sites, which eventually multiply to form an ulcer. Squamous cell carcinomas therefore occur predominantly in places that are exposed to strong sunlight or are constantly irritated in the same way as chronic skin wounds. As with most other types of cancer, other risk factors include a long-term weakened immune system (e.g. by HIV) and nicotine consumption.
The localization
The face is exposed to sunlight often and a lot and is therefore one of the most frequent localizations of a squamous cell carcinoma: About 90% of all squamous cell carcinomas occur on the face. Particularly at risk are those areas that naturally absorb more sunlight, i.e. the lower lip as well as the nose. As protection against the development of squamous cell carcinoma, sufficient sun protection factor should therefore always be ensured at these points.
Like the face, the scalp is one of the areas of the body that is frequently exposed to sunlight. This is especially true if the hair is cut short and a headgear is rarely worn. The diagnosis of scalp cancer is sometimes complicated by the fact that the squamous cell carcinoma is covered by hair and is therefore recognized later than in other parts of the body.
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