Types of Skin Cancer

Basal cell carcinoma
Basal cell carcinoma is also known as BCC or rodent ulcer. Basal cell carcinoma is the most common type of cancer in humans and is particularly prevalent in the Australia and New Zealand. Luckily, this form of skin cancer is very rarely a threat to life.

BCCs arise in otherwise normal appearing skin, unlike squamous cell carcinomas (SCCs), which often arise within pre-existing solar keratoses. They usually grow slowly over months or years so they can vary in size from a few millimetres to several centimetres in diameter. There are several different clinical types.


Squamous cell carcinoma
Squamous cell carcinoma (SCC) is a common type of skin cancer. It is derived from squamous cells, the flat cells that make up the outside layers of the skin, the epidermis. These cells are keratinising i.e., they produce keratin, the horny protein that makes up skin, hair and nails.

Invasive SCC refers to cancer cells that have grown into the deeper layers of the skin, the dermis.They are usually slowly-growing, tender, scaly or crusted lumps. The lesions may develop sores or ulcers that fail to heal.

Most SCCs are found on sun-exposed sites, particularly the face, lips, ears, hands, forearms and lower legs.They vary in size from a few millimetres to several centimetres in diameter. Sometimes they grow to the size of a pea or larger in a few weeks, though more commonly they grow slowly over months or years.

Melanoma
Malignant melanoma is a potentially serious type of skin cancer. It is due to uncontrolled growth of pigment cells, called melanocytes.

Normal melanocytes are found in the basal layer of the epidermis, i.e. the bottom part of the outer layer of the skin. The melanocytes produce a protein called melanin, which protects the skin by absorbing ultraviolet (UV) radiation. Melanocytes are found in equal numbers in black and in white skin, but the melanocytes in black skin produce much more melanin. People with dark brown or black skin are very much less likely to be damaged by UV radiation than those with white skin.

Non-cancerous growth of melanocytes results in moles (properly called benign melanocytic naevi) and freckles (ephelides and lentigines).

Cancerous growth of melanocytes results in melanoma.

Source: Dermnet

Click here to read about Prevention.