Melanoma is a cancer that develops from melanocytes (pigment cells) and is the most serious form of skin cancer.
Understanding the skin
To understand how melanomas develop, it is helpful to understand how the skin works. The skin has two main layers: the epidermis and the dermis.
The skin has two main layers.
The top layer is called the epidermis. This layer contains basal cells, squamous cells and melanocytes. Basal and squamous cells are also called keratinocytes, because they produce keratin, the main component of skin, hair and nails. Melanocytes are cells that produce melanin, the pigment that gives skin its colour.
The layer underneath the epidermis is called the dermis. The dermis is composed of fibres (collagen and elastin). The dermis contains the roots of hairs, glands that make sweat and oil, blood vessels, lymph vessels and nerves.
Like all body tissues, the skin is made of tiny ‘building blocks’ called cells. These cells can sometimes become cancerous when they have been damaged; for example, by ultraviolet (UV) radiation. Skin cancers are named after the type of cell they begin to grow from. The three most common types of skin cancer are basal cell cancer, squamous cell cancer and melanoma.