Melanoma is a serious skin cancer which is curable if detected early.
Melanoma grows from pigment cells (melanocytes) in the outer layer of the skin and mucous membranes (epidermis). Although melanoma usually starts as a skin lesion, occasionally it occurs in other parts of the body such as the eye, brain, mouth or vagina.
Melanoma tends to spread out within the epidermis (radial or horizontal growth phase) before moving into the deeper layer of the skin (the dermis)(vertical growth phase).
It can occur in adults of any age. Melanoma is more common in people aged 50-70. Occasionally it can occur in teenagers but it is almost unheard of in children.
Types of Melanoma
The most common and least dangerous type, a superficial spreading melanoma, starts as a flat, freckle-like spot that first spreads out sideways in the skin. Other types include nodular, acral, lentigo maligna, and amelanotic melanoma.
Staging refers to how far the cancer has spread to other parts of the body. A Stage I melanoma is an early cancer that is limited to the skin.
The risk factors for developing melanoma include:
- Sun exposure particularly during childhood
- Serious sunburn, especially when young – however, melanoma sometimes occurs on areas of the body not normally exposed to the sun
- Family history of melanoma
- Fair skin that burns easily – melanoma is common in people with Northern European ancestry, and is not common among dark-skinned people
- A large number of abnormal moles (called atypical naevi). These moles are usually larger than 6mm, with an irregular shape and multi-coloured. Atypical naevi are not cancers, and a melanoma does not necessarily start in an atypical mole.
Warning signs of Melanoma:
- Change in size especially if it grows larger rapidly.
- Change in colour especially if it develops multiple shades of tan, brown, black, and a mixture of red, white, blue, or the colour spreads from the edge into the surrounding skin.
- Change in shape especially if it develops an irregular notched border which used to be regular.
- Change in height especially if it used to be flat.