Melanin is the pigment that gives skin cells and moles their color. Because it does not have this pigment, amelanotic melanoma can be hard to detect.
What is amelanotic melanoma?
Amelanotic melanoma growths lack pigment and generally are pale pink or reddish lesions.
Image Credit: National Cancer Institute, January 2013.
Healthy moles and other skin cancers contain melanin, but amelanotic melanoma growths cannot produce melanin and therefore lack pigment. This usually results in a very pale pink or reddish lesion.
In itself, an amelanotic melanoma is no more dangerous than any other form of melanoma. Most people who are diagnosed and treated at an early stage survive.
However, the fatality rates for amelanotic melanoma tend to be higher than for other types of melanoma. This is because amelanotic melanoma often goes undetected for longer, which gives it time to spread.
A 2014 study found that 88 percent of people with amelanotic melanoma had survived 5 years following diagnosis, compared to 95 percent of people with pigmented melanoma.
The primary symptom of amelanotic melanoma is an unusual skin growth. Unlike pigmented melanoma, however, amelanotic melanomas are often very faint. They may be pink or red. Some lesions resemble a tiny scar or acne that is healing.
Regular skin checks can help detect amelanotic melanoma. People should know how their skin usually looks, including what their typical scab and healing pattern is, and how their moles typically look.
Some people may find it helpful to take pictures of their moles so that they have a reference to see if the moles have changed. A person should always talk to a doctor if they notice changes in their skin.
Doctors often tell people to follow the ABCD symptom guidelines for skin cancer:
- Asymmetric: Look for moles that are not symmetrical or which look different on either side.
- Border: Look for moles with an irregular border.
- Color: Moles come in different colors, but people should watch for any color changes or uneven coloring.
- Diameter: Look for moles that are wider than a pencil eraser.
However, amelanotic melanoma does not follow this pattern, which is why a person may not notice it until the later stages.
Causes and risk factors
Having numerous moles is a risk factor for amelanotic melanoma.
Sun exposure is the primary risk factor for amelanotic melanoma. These growths tend to occur more often on areas of the body that are frequently exposed to the sun.
Using tanning beds and experiencing frequent sunburns can further increase the risk of developing amelanotic melanoma. The risk of developing any form of melanoma, including amelanotic melanoma, also increases with age.
Melanoma is rare in children, but amelanotic melanoma accounts for a large percentage of these melanomas in children.
Other risk factors for amelanotic melanoma include:
- a family history of melanoma
- fair skin
- having many moles
- a history of severe sunburns
- a previous history of melanoma or another form of skin cancer
To diagnose amelanotic melanoma, a doctor may compare the growth to other skin growths or ask about the history of the lesion.
A biopsy can test the lesion for cancer. If the growth is cancerous, a doctor will assign the lesion a Breslow thickness score that indicates how thick it is. The doctor will also give the lesion a Clark level of invasion, which provides details on how deep into the skin the lesion has spread.
These two scores, along with details about whether the cancer has spread to other areas of the body, help a doctor decide what stage the cancer is at.
The thicker a lesion is, the more likely it is to spread to other areas of the body. This process of spreading is called metastasis.
Early stage cancers may be removed. This can usually be done on an outpatient basis.
However, if the cancer has spread to the lymph nodes or other areas of the body, more aggressive treatment may be necessary. This can include removing the growth, removing lymph nodes, and removing cancerous cells in other areas of the body.
Other treatment options include any one or combination of:
- chemotherapy or anti-cancer drugs to kill cancer cells
- radiation to target cancerous growths
- immunotherapy, which is a type of treatment that uses the body's immune system to fight cancer
A person with amelanotic melanoma may need chemotherapy, radiation, or immunotherapy to fight cancer that has spread elsewhere in the body.
Skin checks will help to detect early signs of melanoma.
Minimizing excessive sun exposure is the best strategy for preventing melanoma, including amelanotic melanoma.
A person should wear sunscreen every time that they are outside. During times of prolonged or direct sun exposure, wearing loose-fitting clothing and a hat can help protect the skin. People should also avoid tanning beds.
Regular skin checks do not prevent amelanotic melanoma but can help people detect signs of melanoma early. Early detection increases the chances of successfully treating cancer.
When to see a doctor
A person should not wait for a suspicious growth to get worse. While dark moles are often more noticeable, people should also look for red or pink lesions that could be amelanotic melanoma.
People with many moles, a history of skin cancer, or very fair skin should discuss with their doctors how frequently they should check their skin for changes, and whether they should see a dermatologist regularly.
Most skin changes are not cancer, but a quick appointment with a doctor offers peace of mind and can help people with melanoma get immediate and life-saving treatment.