Types of melanoma
Cutaneous Melanoma or melanoma of the skin is the most common type of melanoma and can be described in the following ways:
Superficial Spreading Melanoma
Accounts for approx 70% of all diagnosed melanomas. It usually occurs in a previously non cancerous mole and is most commonly found on the trunk and back in men and on the legs and back of women. In the early stages it may look like a freckle or mole that is spreading sideways. Over time it can change in colour, itch or develop irregular borders. It can progress rapidly!
Accounting for around 15% of diagnosed melanomas, it is also the most aggressive. It may appear where a mole or lesion did not exist before. They tend to be darkly pigmented and spread rapidly in depth.
Acral Lentiginous Melanoma
Also called Subungual melanoma only accounts for around 5% of melanomas but makes up 50% of melanomas in those with dark skin. Most commonly found on the palms of the hands, soles of the feet or under finger and toe nails. In the early stages it is often mistaken for a bruise, blood blister or streak in the nail.
Lentigo Maligna Melanoma
Accounts for around 10% of melanomas and often occurs on the face of middle aged to elderly persons who have suffered sun damage. For this reason it often mistaken for sunspots and goes undiagnosed or untreated making it very dangerous. It often has very irregular borders and varying shades of brown or black.
Literally means "without melanin", which is what gives other melanomas their darker colour. Hence, these melanomas are often misdiagnosed or there is a delay in patients seeking treatment. They can appear as a lesion with little or no colour, pink or scar looking. Any lesion that is scar like or appears next to a previously treated melanoma should be examined immediately.
Ocular/Uveal Melanoma is a rare and often aggressive type of melanoma that can arise within the eye. It arises from the melanocytes that give the eye its colour. The exact cause is unknown but risk factors include increased exposure to ultraviolet radiation, having light coloured eyes and being of Caucasian descent. Symptoms of an ocular melanoma tumour can include blurred vision, flashing lights and shadows. However it is not uncommon for a patient to experience no symptoms and be diagnosed during a routine eye check. The best strategy for prevention of ocular/uveal melanoma is to wear UV protective sunglasses and a broad brimmed hat.
Mucosal Melanoma is also rare and accounts for only 1% of all melanomas. As with the skin, melanocytes are present in the mucosal surfaces of the body which line areas such as the sinuses, oral cavity, vagina, bowel and anus. Unlike melanoma of the skin, mucosal melanoma is not linked to sun/UV exposure. Because of location, many mucosal melanomas go undiagnosed and are often quite advanced once identified.