What Is Melanoma?

Melanoma is a type of cancer that begins in cells called melanocytes. Melanocytes make melanin, the brownish pigment that gives skin its color. Most melanomas present as skin cancer, since many melanocytes are found in the upper layer of the skin, called the epidermis. However, melanoma can also appear in other areas of the body, including the eyes and the lining of internal organs. Other names for this type of cancer include malignant melanoma and cutaneous melanoma when it presents on the skin.

Although melanoma is less common than other forms of skin cancer, such as basal cell carcinoma and squamous cell carcinoma, it is considered more dangerous because it has a greater ability to spread to other parts of the body if it is not diagnosed and treated appropriately.

Melanoma is associated with sun exposure and often arises on visible areas of skin, but it can also develop in other sites. Because most melanoma cancer cells produce melanin, the tumors are often brown or black. However, some melanomas stop producing melanin and can appear tan, pink, or even white.

According to the American Cancer Society, more than 100,640 new melanomas are diagnosed in the U.S. each year. Although melanoma accounts for only about 1% of all skin cancer diagnoses, it is responsible for the majority of skin cancer deaths because of its ability to spread to other parts of the body.

In Colorado, it is estimated that there will be around 1990 new cases of melanoma each year. Due to the state’s higher elevation and the fact that many Coloradans love the outdoors, we are one of the 10 states with the highest death rates for melanoma. 

When detected and treated early, however, melanoma is often curable. The estimated five-year survival rate for patients who get treatment for early-stage melanoma is 99%.

Why Come to CU Cancer Center for Melanoma Cancer

CU Cancer Center doctors are experienced in providing comprehensive care for people who have been diagnosed with melanoma. As the only National Cancer Institute Designated Comprehensive Cancer Center in Colorado and only one of four in the Rocky Mountain region, we have doctors who provide top-notch patient-centered care and researchers who are focused on treatment innovations for melanoma.

Currently, there are more than 50 melanoma clinical trials being offered by providers at the CU Cancer Center. These studies are being conducted to improve our knowledge about the diagnosis and treatment of melanoma and can provide patients with additional options for cutting-edge treatments.

→ Melanoma Skin Cancer Clinical Trial Provides Hope When Options Looked Bleak

The CU Cancer Center doctors participate in a weekly melanoma multidisciplinary tumor board discussion. This program brings together medical oncologists, surgical oncologists, radiation oncologists, dermatologists, pathologists, radiologists, and doctors of other specialties to provide newly diagnosed melanoma patients or patients looking for a second opinion with care from multiple specialties at the same time.

The CU Center for Rare Melanomas is an option from the CU Cancer Center for those with rare types of melanomas that are not related to sun exposure, such as mucosal, acral and intraocular melanoma. The center’s mission is to uncover the causes of these rare melanomas and improve their prevention, diagnosis and treatment through research, clinical trials, education, and collaboration with other rare melanoma researchers around the world.

For more information on pediatric melanoma from our clinical partner, and to learn more about the care options, visit the Pediatric Surgical Oncology Program at Children’s Hospital Colorado.

Types of Melanoma

Types of Cutaneous (Skin) Melanoma

There are four primary types of cutaneous melanoma: superficial spreading melanoma, nodular melanoma, lentigo maligna melanoma, and acral lentiginous melanoma. They can be categorized by looking at cells from the tumor under a microscope. It is important to determine the type so the doctor can understand the expected growth patterns.

Superficial spreading melanoma is the most common form of melanoma, accounting for approximately 70% of all diagnoses. It usually occurs on the chest, back, arms, and legs and can develop from an existing mole or appear as a new lesion. Superficial spreading melanoma generally grows across the surface of the skin, but it can also grow down into the skin. The tumors are usually flat and thin or slightly raised with an uneven border. Colors can include shades of tan, brown, black, red, pink, blue, grey, or white, or it may lack pigment altogether.

Nodular melanoma is the most aggressive type of melanoma and accounts for about 15% to 20% of all melanoma diagnoses. It usually develops on the face, chest, back, legs, arms, and scalp. These tumors grow down into the skin layers and are more likely to spread to other parts of the body. They may appear as raised growths that stick out from the skin. Nodular melanoma tumors are usually black or blue-black, but they can also be red, pink, or the same color as the surrounding skin.

Lentigo maligna melanoma accounts for 10% to 15% of all melanoma skin cancers and usually develops in older adults. It typically appears on areas of skin that are regularly exposed to the sun, such as the face, ears, arms, or upper torso. It may look like a flat or slightly raised lesion with uneven, asymmetrical borders. The lesions are often blotchy and darken as they get bigger, varying from blue-black to tan, brown, or dark brown. It may spread outward across the surface of the skin for years before it starts to grow down into deeper layers of skin.

Acral lentiginous melanoma makes up less than 5% of all melanoma cancer diagnoses, but it is the most common form of melanoma found in people of color, including individuals of African, Asian and Hispanic heritage. Unlike most types of melanoma, it is not related to sun exposure and can appear in more hard-to-spot places, such as under the fingernails and toenails, between the toes, and on the palms of the hands and soles of the feet. Acral lentiginous melanoma tumors present as small, flat areas of discolored skin, often dark brown or black. Most tumors spread outward across the surface of the skin before starting to grow down into the skin.   

Desmoplastic melanoma is a rare type of melanoma cancer that can be mistaken for a scar. It often develops as a lump on the head, neck, or upper back and can be the same color as the surrounding skin.

Other Types of Melanoma

Although most melanomas occur in the upper layer of the skin, some rarer forms can develop any place melanocytes exist in the body.

Mucosal melanoma develops on the thin, moist lining (the mucosa or mucous membrane) of some organs and other parts of the body, such as the nasal passages, mouth, esophagus, urinary tract, rectum, anal canal, and vagina.

Intraocular melanoma starts in the eye and is the most common type of eye cancer. It is usually found in the uvea — the layer beneath the white of the eye.

The following information is focused on cutaneous melanoma, which is the most common kind of melanoma. For more information about mucosal melanoma and intraocular melanoma, talk to your doctor.

Risk Factors for Melanoma

Melanoma has multiple risk factors — behaviors or conditions that increase a person’s risk of developing the cancer. 

Ultraviolet (UV) exposure: Whether from the sun or indoor tanning, excessive or unprotected exposure to ultraviolet radiation is the main risk factor for developing melanoma. People who have had one or more blistering sunburns in their lives have a higher risk of developing melanoma, and the more sunburns someone has had, the greater the risk. People who live close to the equator experience higher amounts of UV radiation, as do people who live at a high elevation.

Many or atypical moles: Moles are bumps or spots on the skin made up of groups of melanocytes. They are usually brown or pink with smooth, regular borders. Most moles are harmless, and most people have a few moles. However, people with many moles (50 or more) and people with large or atypical moles have an increased risk for melanoma.   

Fair skin: People with fair skin, light eyes, and blond or red hair have a higher risk of developing melanoma. People with dark skin have a lower risk of developing most forms of melanoma, though they may be more likely to develop acral lentiginous melanoma, which occurs on areas of the body not normally exposed to the sun, such as the soles of the feet and palms of the hands.

History of skin cancer: People who have already had any type of skin cancer have a greater risk of developing melanoma.

Genetics: One in every 10 melanoma patients has a family member who has also been diagnosed with melanoma. Other hereditary conditions can also increase the risk of developing melanoma, including familial atypical multiple mole and melanoma syndrome (FAMMM), which is associated with an inherited mutation in the CDKN2A gene; atypical mole syndrome (AMS, also known as Dysplastic Nevus Syndrome); xeroderma pigmentosum; Werner syndrome; and retinoblastoma eye cancer.

Age and gender: The risk of melanoma increases with age, and it is more common in men than in women. However, it is also found in adolescents and young adults and is becoming one of the most common cancers in people younger than 30, especially women.

Weakened immune system: People with weakened immune systems have an increased risk of developing melanoma. Some examples include people with human immunodeficiency virus (HIV) and patients who are currently taking drugs to suppress their immune systems, such as after an organ transplant.

Symptoms of Melanoma

Melanoma can usually be treated successfully if it is diagnosed early, before the cancer has spread to other parts of the body. That’s why it’s important to understand the most common melanoma symptoms.

Melanoma typically presents as a new, irregular or changing mole. Most moles are non-cancerous (benign), but a mole that changes in size, shape, or color may be a sign of melanoma skin cancer. These cancerous (malignant) tumors can destroy nearby tissue and may spread to other parts of the body.

Experts recommend that people examine their skin once a month to identify potential skin cancers, taking note of any new moles and checking existing moles or lesions for changes. Use the first five letters of the alphabet — or the "ABCDE rule” — to assess whether a mole might be cancerous:

A is for Asymmetry: If someone were to draw a line down the middle of the mole, would the two halves match? If not, it could be a sign of melanoma.

B is for Border: Are the edges of the mole uneven, irregular, jagged, scalloped, notched, or blurry? Does the color spread past the border of the mole into the area of skin around the mole? These are potential indicators for melanoma.

C is for Color: Is the mole a single, consistent color throughout? If not, it could be cancerous. Melanomas are often varying shades of tan, brown, black, blue, grey, red, pink, or white.

D is for Diameter: Is the mole larger than 6 mm across (about the size of a pencil eraser)? Large moles are more likely to develop into melanoma.

E is for Evolving: Has the mole changed color, size, shape, elevation, or texture? Any change or new symptom (such as bleeding, oozing, itching, burning, or crusting) may be a melanoma symptom.

Patients should make an appointment with their primary care provider or dermatologist if they find a mole that fits the above criteria and get a professional skin exam at least once a year.

Diagnosing Melanoma

The only definitive way to diagnose melanoma is through a biopsy, but the process may involve many steps.

The doctor will usually begin by asking about the patient’s health history and examining their skin to look for any abnormal moles or lesions. They may also check for enlarged lymph nodes by feeling the neck, groin, or under the arms. Based on their findings, they doctor may refer the patient to a specialist, such as a dermatologist or surgical oncologist, for further diagnosis.

The next step in diagnosing melanoma is usually a skin biopsy. During a biopsy, the doctor, dermatologist or surgical oncologist will remove a sample of tissue and send it to a lab to test for cancer cells. The way in which the biopsy is performed and the size of the biopsy will depend on what the growth looks like, its size, and its location on the body. Common techniques are excisional biopsy, incisional biopsy, shave biopsy, and punch biopsy.  

Stages of Melanoma

After diagnosing melanoma, the doctor will take steps to determine the stage of the disease. The stage is determined by several factors, including how deep the tumor has grown into the skin on the biopsy, and if it has spread (metastasized) to lymph nodes or other parts of the body. The stage significantly impacts both the prognosis and treatment options. 

The staging process may require additional tests, such as lymph node biopsies, computed tomography (CT) scans, magnetic resonance imaging (MRI) scans, or positron emission tomography (PET) scans.

Doctors determine the stage of melanoma using the TNM system, which was developed by the American Joint Committee on Cancer. The TNM system assesses the size and extent of the tumor (T-tumor) and whether it has ulcerated; whether the cancer has spread to nearby skin or lymph nodes (N-node); and the presence and extent of metastasis (M-metastasis) to distant lymph nodes or organs like the lungs or brain.

After the TNM assessment, an overall stage number from 0 to 4 is assigned. In general, the lower the stage the better the prognosis.

Doctors may refer to stages 1–2 as early-stage melanoma, meaning that the cancer is still contained to the skin where it started and has not spread to lymph nodes or other parts of the body.

Stage 0: The tumor is localized in the top or outer layer of the skin. This noninvasive stage, also called melanoma in situ, does not have the ability to spread to other parts of the body and is a precancerous skin condition.

Stage 1: The cancer is localized but invasive, meaning it has penetrated beneath the top layer of skin. The tumor is no more than 2 mm thick and usually is not ulcerated.

Stage 2: The cancer has not spread to nearby lymph nodes or distant parts of the body, but the localized tumor has more aggressive features. The tumor is more than 1 mm thick with ulceration and may be thicker than 4 mm.

Stage 3: The cancer has reached one or more nearby lymph nodes or has spread in the skin through a lymphatic vessel (satellite and in-transit tumors). The cancer has not spread to distant parts of the body. This is also called locoregionally advanced melanoma.

Stage 4: The cancer has spread to distant areas or the body, lymph nodes or organs, usually the lungs, liver, brain, bones and gastrointestinal tract. This is also called metastatic melanoma.

These stages can be further broken down based on the size of the original tumor and the extent to which the cancer has spread.

Treatments for Melanoma

The treatment for melanoma is tailored to each patient and depends on the size and location of the tumors, the stage, and the patient’s overall health and personal preferences. Melanoma care teams may include multiple health care specialists, such as primary care providers, dermatologists, surgical oncologists, medical oncologists, and radiation oncologists, as well as physician assistants, nurse practitioners, nurses, psychologists, social workers, and rehabilitation specialists.

Some of the primary treatments for melanoma skin cancer include surgery, immunotherapy, targeted drug treatments, radiation therapy, and chemotherapy. Most melanoma patients receive at least one of these treatments but may be offered more in combination. Some melanoma patients may also be eligible to participate in clinical trials — controlled research studies of new or experimental treatments or procedures that may fall into any of the treatment categories below.

Surgeries for Melanoma

Surgery is the primary treatment for most melanomas and may be the only treatment required for early-stage melanoma cancers. CU Cancer Center surgeons provide state-of-the-art surgical care for cancer patients.

In a wide local excision surgery, the entire tumor or lesion is removed, along with some of the normal tissue surrounding it (the surgical margin). The sample is then sent to a lab, where a pathologist analyzes it to determine the extent of disease and whether any cancer cells may have been left behind.

Sentinel lymph node biopsies are diagnostic surgeries used to determine the stage of the melanoma cancer in some patients. During this procedure, a surgeon removes one or more lymph nodes to see whether the lymph nodes contain cancer cells.

Therapeutic lymph node dissection is a surgery that may be used to remove all the lymph nodes in an area when it is already known that the melanoma has spread to lymph nodes in that area. This treatment approach once was common, but it is now becoming less common because of new treatment options.

In rare cases where the melanoma is located on a finger or toe and has grown deeply, part or all of that digit may need to be amputated.

Immunotherapy for Melanoma

Immunotherapy uses drugs to enhance the immune system’s ability to fight cancer. Immunotherapy medications may be recommended after surgery when the cancer has spread to the lymph nodes or other areas of the body, or if the cancer has high risk features for spread to lymph nodes or other areas of the body.

Doctors use several forms of immunotherapy to treat melanoma, including immune checkpoint inhibitors, also called checkpoint blockade therapies. These drugs target the body’s checkpoint proteins, helping restore the immune system’s natural defenses against cancer cells. Other immunotherapies for melanoma include oncolytic virus therapy, which uses a lab-altered virus to infect and kill cancer cells, and adoptive cell transfer, which harnesses white blood cells called tumor-infiltrating lymphocytes to attack the cancer.

Targeted Drug Treatments for Melanoma

Targeted therapies use drugs to inhibit the action of defective genes and molecules and halt the growth and spread of melanoma cells while limiting harm to normal cells. This form of treatment is most effective in patients with metastatic melanoma who have specific mutations in the BRAF gene.

Radiation Therapy for Melanoma

Radiation therapy employs high-energy light waves to destroy cancer cells. Although doctors rarely use radiation as a primary treatment for melanoma, it may be used after surgery to reduce the risk of the cancer coming back or shrink melanomas that can’t be removed completely. Doctors may also use radiation as a palliative treatment for melanomas that have spread to the brain or other distant sites to relieve symptoms and decrease pain.

Chemotherapy for Melanoma

Chemotherapy uses drugs to destroy cancer cells. Because newer frontline treatments such as immunotherapy and targeted drug therapies are typically more effective at treating melanoma (and produce fewer side effects), doctors use chemotherapy less often now for the treatment of melanoma.

Chemotherapy may be injected directly into an arm or leg (regional chemotherapy) for locally recurrent melanoma skin cancer confined to one limb. Isolated limb infusion or perfusion delivers a high dose of chemotherapy called melphalan with or without other medications to the local site of a tumor in the arm or leg. It is performed only in specific circumstances when the cancer cannot be surgically removed.

The University of Colorado (CU) Cancer Center partners with UCHealth, Children’s Hospital Colorado, and Rocky Mountain Regional VA to provide clinical care. Please make an appointment with one of our clinical partners to be seen by a CU Cancer Center doctor.


UCHealth Cancer Care - Anschutz Medical Campus
1665 Aurora Court Anschutz Cancer Pavilion
Aurora, CO 80045

UCHealth Cherry Creek Medical Center
100 Cook Street
Denver, CO 80206

UCHealth Cancer Center - Highlands Ranch
1500 Park Central Drive
Highlands Ranch, CO 80129

UCHealth Lone Tree Medical Center
9548 Park Meadows Drive
Lone Tree, CO 80124

Children's Hospital Colorado:
13123 East 16th Avenue
Aurora, CO 80045

Rocky Mountain Regional VA Medical Center:
1700 North Wheeling Street
Aurora, CO 80045-7211


Latest in Melanoma from the CU Cancer Center

Loading items....

Information reviewed by Camille Stewart, MD, in July 2022.
CMS Login