The Mayo Clinic describes skin cancer as the abnormal growth of skin cells, most commonly on skin that is exposed to the sun, although it can start anywhere. There are three main types of skin cancer: basal cell carcinoma, squamous cell carcinoma and melanoma. These cancers are named after the kinds of cells they start in or resemble and can act very differently from one another.
Basal Cell Carcinomas
According to the American Cancer Society, basal cell cancer cells look similar to cells in the lowest layer of the epidermis, which is called the basal cell layer. These cancers comprise the majority of skin cancers, with eight out of 10 skin cancers being of this kind. Basal cell cancers typically start on areas of the skin that are exposed to sun, but can start anywhere, and are usually slow growing and rarely metastasize. Despite its slow-growing nature, if it is not treated, the cancer can spread to other parts of the skin and bones.
Squamous Cell Carcinoma
According to the American Cancer Society, squamous cell carcinoma skin cancers make up approximately two out of 10 skin cancers and typically appear on areas that are exposed to the sun more often, but can also start in scars. The Mayo Clinic describes these kinds of skin cancers as being more aggressive than basal cell cancers and having a higher probability of spreading to fatty tissues, lymph nodes and other organs of the body.
Melanomas
Melanomas are a kind of skin cancer that are also known as malignant melanomas and start in skin cells called melanocytes, which are skin cells that produce the pigment melanin. These cancers can occur anywhere on the body, but are more common on the chest and back in men, and arms and legs in women. The face and neck are also common sites for this cancer to begin. Melanomas are much more rare than basal cell and squamous cell cancers, but can be deadly and spread rapidly if not caught early.
