ON THIS PAGE: You will find some basic information about this disease and the parts of the body it may affect. This is the first page of Cancer.Net’s Guide to Melanoma. To see other pages, use the colored boxes on the right side of your screen. Think of those boxes as a roadmap to this full guide. Or, click “Next” at the bottom of each page.
About the skin
The skin is the body’s largest organ. It protects against infection and injury, and it helps regulate body temperature. The skin also stores water and fat and produces vitamin D.
Skin is made up of two main layers: the epidermis (outer layer of skin) and the dermis (inner layer of skin). The deepest layer of the epidermis, just above the dermis, contains melanocytes, which are pigment-producing (color-producing) cells.
Melanoma begins when normal melanocytes change and grow uncontrollably, forming a mass called a tumor. A tumor can be benign (noncancerous) or malignant (cancerous, meaning it can spread to other parts of the body).
Frequently, melanoma develops from a pre-existing mole. Melanoma occurs most commonly on the skin of men’s backs or on women’s legs, but melanoma can occur anywhere on the body, including the head and neck, the skin under the fingernails, and even the soles of the feet or palms of the hands.
When found early, melanoma can often be cured with surgery. However, melanoma is also the most serious form of skin cancer and can grow deep into the dermis, invading lymph and blood vessels. The median age at which people are diagnosed with melanoma is just above 50 years old. Still, melanoma occurs in young adults with greater frequency than many other cancer types.
This section focuses on cutaneous melanoma, which is melanoma that arises on the skin. Melanoma can also develop in the mucous membranes that line the mouth, gastrointestinal tract, vagina, and other locations around the body. Melanoma may also develop in the eye. You can learn more about melanoma diagnosed elsewhere in the body, such as melanoma of the eye, melanoma of the anus, and melanoma of the vagina, in these specific cancer type sections. For information on non-melanoma skin cancer, review the section on basal cell and squamous cell skin cancers.
Looking for More of an Overview?
If you would like additional introductory information, explore these related items. Please note these links take you to other sections on Cancer.Net:
- ASCO Answers Fact Sheet: Read a one-page fact sheet (available in PDF) that offers an easy-to-print introduction to this type of cancer.
- Cancer.Net Patient Education Video: View a short video led by an ASCO expert in this type of cancer that provides basic information and areas of research.
Or, choose “Next” (below, right) to continue reading this detailed section. To select a specific topic within this section, use the colored boxes located on the right side of your screen.