What kind of cancer is skin cancer?

Skin cancer is the uncontrolled growth of abnormal skin cells. It is not a single disease, but rather a group of related diseases that can vary in appearance and severity. There are three main types of skin cancer:

- Basal cell carcinoma (BCC) is the most common type of skin cancer. It arises from the basal cells, which are located at the bottom of the epidermis, the outermost layer of the skin. BCCs typically appear as small, pearly bumps or sores that grow slowly over time. They are usually found on sun-exposed areas of the skin, such as the face, neck, arms, and legs. BCCs are rarely fatal, but they can be locally aggressive and can cause significant damage to the skin if not treated.

- Squamous cell carcinoma (SCC) is the second most common type of skin cancer. It arises from the squamous cells, which are located in the middle layer of the epidermis. SCCs typically appear as scaly, red patches or bumps that can grow quickly over time. They are also usually found on sun-exposed areas of the skin, but they can also occur on the mucous membranes, such as the lips, mouth, and genitals. SCCs can be more aggressive than BCCs and can metastasize, or spread to other parts of the body, if not treated promptly.

- Melanoma is the most serious type of skin cancer. It arises from the melanocytes, which are cells in the epidermis that produce melanin, the pigment that gives skin its color. Melanomas typically appear as irregularly shaped, dark brown or black patches or bumps that can change in size and shape over time. They can occur anywhere on the body, but are most common on the back, legs, and arms. Melanomas are the most aggressive type of skin cancer and can metastasize quickly if not treated early.