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. There are a few different types of cutaneous melanoma:
    • Superficial Spreading Melanoma 
    • Nodular Melanoma 
    • Acral Lentiginous Melanoma 
    • Lentigo Maligna Melanoma
    • Desmoplastic 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. Conjunctival melanoma may also be included in this category. Learn more about CURE OM, the MRF’s initiative focused on ocular melanoma

Unlike other cancers, most melanomas 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. This is referred to as metastatic melanoma. When melanoma spreads, it most commonly spreads to the liver, lungs, bones and brain, making treatment more difficult. Learn more about the different melanoma treatment options here.  

What causes melanoma?

Research suggests that nearly 90% of melanoma cases can be linked to exposure to ultraviolet (UV) rays - either from natural sources, like the sun, or from artificial sources, like 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 all diagnoses, especially mucosal and ocular melanoma cases. Current research points to a combination of family history, genetics and environmental factors that are to blame. Take a look at our Melanoma Fact Sheet to learn more!

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