Skin cancer can present in different ways, depending on the type. Signs that may require medical assessment include:
New or unusual growths – such as a firm red nodule, a flat scaly patch, or a sore that does not heal within a few weeks
Changes in moles – including changes in size, colour, shape, or texture, or moles that become itchy, tender, or begin to bleed
Irregular borders – edges that are uneven or not clearly defined
Colour variations – moles or growths with multiple colours, such as brown, black, white, red, or blue
Asymmetry – one half of a mole or lesion does not match the other half in shape or colour
Larger diameter – lesions greater than 6 millimetres, although skin cancers can also be smaller
Evolving or changing lesions – any mole or skin growth that changes over time in size, shape, colour, or symptoms such as itching, bleeding, or crusting
These signs do not always indicate skin cancer, but they should be checked by a qualified health professional.
In addition to the three main types of skin cancer, rare forms such as Merkel cell carcinoma and dermatofibrosarcoma protuberans can occur. Regular skin checks and prompt medical review of any suspicious changes can help with early detection and management.