Melanoma Skin Cancer

Skin cancers are cancers that arise from the skin. They are due to the development of abnormal cells that have the ability to invade or spread to other parts of the body. There are three main types: basal-cell cancer, squamous-cell cancer and melanoma. The first two together along with a number of less common skin cancers are known as nonmelanoma skin cancer . Basal-cell cancer grows slowly and can damage the tissue around it but is unlikely to spread to distant areas or result in death. Melanomas are the most aggressive. Signs include a mole that has changed in size, shape, color, has irregular edges, has more than one color, is itchy or bleeds.

Greater than 90% of cases are caused by exposure to ultraviolet radiation from the Sun. This

They rarely metastasize and rarely cause death. They are easily treated with surgery or radiation. Squamous-cell carcinomas are common, but much less common than basal-cell cancers. They metastasize more frequently than BCCs. Even then, the metastasis rate is quite low, with the exception of SCC of the lip, ear, and in people who are immunosuppressed. Melanomas are the least frequent of the 3 common skin cancers. They frequently metastasize, and could potentially cause death once they spread.

Less common skin cancers include: dermatofibrosarcoma protuberans, Merkel cell carcinoma, Kaposi 's sarcoma, keratoacanthoma, spindle cell tumors, sebaceous carcinomas, microcystic adnexal carcinoma, Paget 's disease of the breast, atypical fibroxanthoma, leiomyosarcoma, and

The use of many immunosuppressive medications increases the risk of skin cancer. Cyclosporin A, a calcineurin inhibitor for example increases the risk approximately 200 times, and azathioprine about 60 times.

Pathophysiology

A malignant epithelial tumor that primarily originates in the epidermis, in squamous mucosa or in areas of squamous metaplasia is referred to as a squamous-cell carcinoma.

Their disposal tends to be similar to that of normal epidermis: immature/basal cells at the periphery, becoming more mature to the centre of the tumor masses. Tumor cells transform into keratinized squamous cells and form round nodules with concentric, laminated layers, called "cell nests" or "epithelial/keratinous pearls". The surrounding stroma is reduced and contains inflammatory infiltrate . Poorly differentiated squamous carcinomas contain more pleomorphic cells and no keratinization. and squamous-cell carcinoma. There is little evidence that it is effective in preventing basal-cell carcinoma. Other advice to reduce rates of skin cancer includes avoiding sunburning, wearing protective clothing, sunglasses and hats, and attempting to avoid sun exposure or periods of peak exposure. The U.S. Preventive Services Task Force recommends that people between 9 and 25 years of age be advised to avoid ultraviolet