A definition of skin cancer and briefly explain the types

Skin cancer is a type of disease where there is uncontrolled growth of skin cells that are abnormal. It occurs when the DNA of some skin cells is damaged, most often by ultraviolet rays from the sun, and the damage is not repaired. This damaged DNA causes the skin cells to behave abnormally. When they form new cells, these daughter cells have defects in their genes which cause the cells to multiply rapidly and form malignant tumours.

Examples of skin cancers are:

1. Basal cell cancer. This is the most common type of skin cancer and appears after the age of 30 yrs.

2. Paget's disease. This a rare type of skin cancer and it appears on the nipple or groin.

3. Kaposi's sarcoma. This is a skin cancer caused by a virus of the herpes family of viruses.

4. Malignant melanoma. This is the most rare type of skin cancer but it spreads very quickly and aggressively to different body parts such as the lungs and liver.