Melanoma is a less common type of skin cancer than BCCs and SCCs, but accounts for a relatively higher proportion of skin cancers seen in young adults. It is dangerous because of its ability to spread throughout the body and may be fatal, with approximately 1200 Australians dying from melanoma annually. Fortunately, however it is nearly always curable when diagnosed and treated early. Most melanomas start in the top layer of the skin and slowly spread outwards within the top layer of skin before moving into the deeper layers where the cancer cells can enter the lymph channels and bloodstream.
Melanomas can occur on any part of the skin including relatively sun protected sites, but most often they happen on sun exposed parts. In men they more often occur on the torso whilst in women they are more common on the legs. Half will develop from a pre-existing mole with the other half arising from normal skin.
Rates of melanoma are rising, although the greatest increase is amongst elderly males. While melanoma can occur at any age, they are more common in older people. However, because cancers in general are less common in young people, melanomas are one of the commoner cancers of young adults.
Melanomas should be suspected if there is a changing mole or new onset mole. They will enlarge over weeks to months but are rarely symptomatic and only cause pain or bleeding if they are advanced. Examination of changing moles with illumination devices such as a dermatoscope can aid in the diagnosis, but the diagnosis can only be made with 100% certainty after the excision of the lesion.
Treatment always involves surgery, but the extent of surgery depends on how advanced the melanoma is. Most melanomas do not require any other treatment but advanced melanomas may require additional tests and treatments such as radiotherapy or chemotherapy.