Exposure to the harmful radiation of the sun causes damage to the genetic material of the skin cells. These altered skin cells divide uncontrollably to form a tumour mass. These appear as new growth or sore that does not heal. The cancer of the basal cells is called basal cell cancer and that of keratinocytes is called squamous cell cancer. The cancer of the melanocytes is called melanoma. The basal cell cancer and squamous cell cancer together are categorised as non-melanoma skin cancers.
Basal cell carcinoma – Basal cell carcinoma is the most common form of skin cancer. About 80% of skin cancer cases are found to be basal cell carcinoma. It can look like a small pearly nodule or pinkish patch on the skin. It can also appear as a sore that seems to heal but returns repeatedly or as yellowish waxy scar. It develops as a result of short-term exposure to harmful UV rays such as during vacations and on the sun-exposed areas such as the face, ears, scalp, neck and trunk. These cancers grow slowly and rarely spread to other parts of the body.
Squamous cell carcinoma – About 20% of skin cancers are squamous cell carcinoma. Squamous cell carcinoma develops most commonly in middle-aged and elderly people with fair complexion and long-term exposure to sun rays. It appears as a crusted or scaly area over your skin. It is most commonly seen on sun-exposed areas of the body.
Melanoma – Melanoma mostly develops from the mole. Melanomas are malignant and can spread to other parts of the body if not treated early. Any change in the size, colour, shape and feel of the existing mole or appearance of a new mole should be reported and checked by the skin cancer surgeon/specialist.
There are other rare type of skin cancers such as merkel cell carcinoma, Kaposi’s sarcoma and T cell lymphoma of the skin that account for only 1% of the total skin cancers.