Squamous cell carcinomas, or SCCs, are so called because they develop from the squamous cells which make up the bulk of the epidermis. They are much less common than BCCs. They occur in older people on sun-exposed sites such as the face, hands, arms and the lower lip. Sometimes they develop in solar keratoses.
People whose immune system is suppressed, for example people with kidney transplants or anyone taking immunosuppressive drugs, have a higher risk of SCC. Such people are at a much higher risk of skin cancer and must be particularly careful to avoid the sun.
SCCs look like scaly firm lumps on sun-exposed areas. Sometimes these are quite tender. Bleeding and ulceration may occur, although less commonly than with BCCs. The risk of spread throughout the body is about 2 per cent, but is more likely to occur for those on the lower lip and ear. Thus these lesions should be treated as soon as possible.
The appropriate treatment of SCCs is surgical removal. Occasionally, especially in the elderly, treatment with radiotherapy rather than surgery may be appropriate.
Although sun exposure definitely causes BCC, there are other factors which are important. Some people have a genetic predisposition to develop this type of skin cancer. Such people have not had a history of excessive sun exposure in the past. In such cases there is often a history of multiple BCCs in other family members.
In summary BCCs are the most common type of skin cancer, which means they are the most common type of any cancer. Different types of BCC have different appearances and different patterns of growth. Since BCCs rarely spread (metastasize) throughout the body, the main problem with them is that if they are not removed early they can spread locally, ultimately requiring extensive disfiguring surgery. It is important to recognize them before they get to this stage. A skin spot which bleeds may be a BCC!