Melanoma is a type of cancer that forms in pigment cells (melanocytes). It is most common in the skin and, if left untreated, it is the most aggressive form of skin cancer.
The skin is the largest organ in the body and is comprised of three main layers; the epidermis, dermis and fat. The dermis and adjacent fatty tissue layers are not visible to the naked eye. Skin is rich in cell types that have the potential to grow cancer if exposed to repeated ultraviolet trauma, such as excessive sun exposure.
The skin has 3 layers.
The epidermis is the outermost layer of the skin which provides a waterproof barrier and creates our skin tone.
The dermis is the next layer and contains tough connective tissue, hair follicles and sweat glands.
The deepest layer is called the hypodermis which is the subcutaneous fat layer under the skin.
Melanocytes clustered in groups form moles.