What is melanoma?

Melanoma is usually, but not always, a cancer of the skin. It begins in melanocytes – the cells that produce the pigment melanin that colors the skin, hair and eyes. Melanocytes also form moles, where melanoma often develops. Having moles can be a risk factor for melanoma, but it’s important to remember that most moles do not become melanoma. 

There are three general categories of melanoma:

  • Cutaneous Melanoma is melanoma of the skin. Since most pigment cells are found in the skin, cutaneous melanoma is the most common type of melanoma. Cutaneous melanoma can be described in four main ways:
    • Superficial Spreading Melanoma 
    • Nodular Melanoma 
    • Acral Lentiginous Melanoma 
    • Lentigo Maligna Melanoma 
  • Mucosal Melanoma can occur in any mucous membrane of the body, including the nasal passages, the throat, the vagina, the anus, or in the mouth
  • Ocular Melanoma, also known as uveal melanoma or choroidal melanoma, is a rare form of melanoma that occurs in the eye. Learn more about CURE OM, the MRF’s initiative focused on ocular melanoma

Unlike other cancers, melanoma can often be seen on the skin, making it easier to detect in its early stages. If left undetected, however, melanoma can spread to distant sites or distant organs. Once melanoma has spread to other parts of the body (known as stage IV), it is referred to as metastatic melanoma, and is very difficult to treat. In its later stages, melanoma most commonly spreads to the liver, lungs, bones and brain; at this point, the prognosis is very poor.

What causes melanoma?

Research suggests that approximately 90% of melanoma cases can be linked to exposure to ultraviolet (UV) rays from natural or artificial sources, such as sunlight and indoor tanning beds. However, since melanoma can occur in all melanocytes throughout the body, even those that are never exposed to the sun, UV light cannot be solely responsible for a diagnosis, especially mucosal and ocular melanoma cases. Current research points to a combination of family history, genetics and environmental factors that are also to blame. Read our Melanoma Fact Sheet for more information!

Taking steps to prevent melanoma is therefore the best first step in protecting yourself and your skin. It is important to learn about all of the risk factors.

Symptoms of melanoma - What should I look for?

Symptoms of melanoma and other skin cancers vary from person to person, but if you suspect that a spot on your skin fits the following descriptions, talk to your doctor right away. Note that not all skin cancers and melanomas fall into these categories, so just use this list as a guideline:

  • A change on the skin - this could be a new spot, or a change in color, shape or size of a current spot
  • A sore that doesn't heal
  • A spot or sore that becomes painful, itchy, tender or bleeds
  • A spot or lump that looks shiny, waxy, smooth or pale
  • A firm red lump that bleeds or appears ulcerated or crusty
  • A flat, red spot that is rough, dry or scaly