SKIN CARE: SQUAMOUS CELL CARCINOMA
The S.C.C Is a tumour arising from the prickle cells of the epidermis which lie above the basal layer. This form of cancer easily Invades the dermis, and may on occasions spread to local lymph glands or more widely through the blood stream.
Causes. S.C.C.s are much more prevalent on sun-damaged skin. They may however arise following prolonged exposure to chemical carcinogens such as tar, lubricating oils, creosote and soot. Occasionally they arise at the site of an old Injury, such as a burn or leg ulcer. The taking of arsenic for medical purposes, many years previously, will predispose one to developing a S.C.C. The majority of these cancers are due to the cumulative effect of solar damage in genetically predisposed people, and occur on sun-exposed areas. The incidence is high amongst outdoor workers—especially those with fair or freckled complexions—living in countries like Australia, South Africa, or in the American State of California. (The incidence is 15 times less in blacks than in whites of the same area.
Features. A S.C.C. rarely arises in healthy-looking skin. They usually appear against a background of blotchy pigmentation, alternate thickening and thinning of the skin, and wrinkling. Frequently, they occur within a longstanding solar keratosis. The most common sites are the backs of the hands, the arms and the facial area.
The earliest sign of a S.C.C. is often a firm thickening of the skin, usually at the base of a solar keratosis. More frequently, however, the earliest sign is a warty growth, or a small ulcer, with a rolled solid border. Initially the ulcer is not obvious because of a firmly adhering crust, which bleeds when it is knocked off. The lower lip is a favourite site for these S.C.C.s. Here a S.C.C. may be preceded by a white flat patch, known as leukoplakia, or dry, scaly, cracked lips. It may begin as a persistent fissure or crack, which becomes hard and ulcerated, or as a warty or fleshy, red growth.
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