Seborrheic keratosis causes discolored, slightly raised patches on the skin. While these patches may resemble signs of skin cancer, they are harmless.
Seborrheic keratoses are noncancerous skin growths that can look a lot like melanoma. About
This article discusses the differences between seborrheic keratosis and skin cancer.
Seborrheic keratosis and melanoma can look similar. However, despite the visual similarity, seborrheic keratosis is not a risk factor for skin cancer or a form of precancer.
Seborrheic keratoses are harmless skin growths that often appear as the skin ages. Some people have just one, but it is common to develop several.
Seborrheic keratoses can range in color from black to white. They often appear patchy and can occur anywhere on the body. The growths may look waxy, and people might initially mistake them for unusual-looking scabs.
Seborrheic keratoses do not typically cause symptoms, but some people dislike the way they look. Occasionally, they become inflamed or irritated, causing pain and itching. An injury to a seborrheic keratosis can cause an infection.
Learn more about seborrheic keratosis here.
Melanoma is a type of skin cancer that first appears as a new mole or a change in an existing mole. Melanomas are typically asymmetrical, larger than 6 millimeters (mm), and more than one color.
However, size is not a definitive sign of melanoma. Noncancerous moles may be larger than this, while cancerous moles can be smaller.
However, with prompt treatment, more than 91% of people with melanoma will survive 5 years or more after their first diagnosis.
Learn more about melanomas and how to identify them here.
Melanoma and seborrheic keratoses are not easy to distinguish, but a dermatologist may be able to tell the difference based on a physical examination.
In some people, a melanoma may look like seborrheic keratosis. People with a history of seborrheic keratosis might not notice melanoma in its early stages if they are accustomed to unusual skin growths.
In some cases, however, it is necessary to take a biopsy of the growth to check for cancer under a microscope.
Doctors do not know what causes seborrheic keratosis or whether it is possible to reduce the risk of developing these skin growths.
The growths are not contagious and do not spread from contact with others. Some people notice that the growths tend to spread on their skin over time.
The primary risk factor for seborrheic keratoses is age. Other risk factors include:
Over time, ultraviolet (UV) radiation from the sun or tanning beds can change the way the skin behaves. This can lead to cancer, including melanoma.
While sun exposure is one of the
Other risk factors for melanoma include having:
- lots of moles, especially if the moles are unusual
- fair skin, light eyes, and light hair
- a history of melanoma or other skin cancers
- a weak immune system due to HIV or AIDS, chemotherapy, some medications, and some illnesses
- a family history of melanoma
- a genetic mutation that increases the risk of melanoma
- moles that are changing
A doctor may be able to distinguish melanoma from seborrheic keratosis with a visual examination. When a doctor is uncertain of the diagnosis or if a person has a range of risk factors for melanoma, it may be necessary to take a biopsy of the growth.
Seborrheic keratoses are typically:
Melanoma tends to change and grow over time, so anyone who has a growth that looks like seborrheic keratosis but changes in shape or color should contact a doctor.
People should watch for the following signs:
- Asymmetry: A mole or growth that looks different on one side is a potential sign of melanoma.
- Border: Melanoma moles tend to have irregular borders or borders with jagged edges.
- Color: Melanoma often causes moles with an uneven or unusual color.
- Diameter: Moles that change in size and those larger than 6 mm are more likely to be a melanoma.
- Evolving: Melanoma growths may change shape, size, and color over time.
Seborrheic keratoses do not usually cause symptoms and do not necessarily require treatment. However, some people prefer to have them removed because they find the growths unattractive.
Doctors can remove a seborrheic keratosis using a range of minor surgical procedures. These include:
- cryotherapy, which is the use of cold temperatures to destroy tissue
- curettage, or scraping the skin with a surgical tool to remove cells
- electrotherapy, which uses electrical energy to destroy affected tissues
- excision, which is a surgical removal of tissues
Treatment for melanoma depends on a range of factors, including the stage of cancer and whether it has spread to other areas of the body.
Learn more about cancer stages here.
However, treatment almost always requires removing the cancer as well as any lymph nodes to which it has spread.
Doctors can often successfully treat early stage melanomas by removal alone. More advanced melanomas typically
Advanced treatments include:
- immunotherapy, a type of therapy that uses the body’s immune system to treat the cancer
- targeted drug therapies that treat receptors on tumors
Both seborrheic keratosis and melanoma can appear in many forms. People concerned about skin growths should not try to self-diagnose their condition and should not assume that a new skin growth is benign.
People should contact a doctor if they develop any new skin growths, particularly if the growth changes over time or there is a family history of skin cancer.
People with seborrheic keratosis should get regular skin checks. This reduces the likelihood of mistaking melanoma for just another seborrheic keratosis growth. Speaking with a doctor annually for a skin and mole check should help reduce the risk of having advanced cancer.
Seborrheic keratosis is a skin condition that causes discolored skin growths similar to moles. These growths may appear similar to melanomas but are noncancerous.
Seborrheic keratoses are not a risk factor for skin cancer, nor do they cause skin cancer. People may wish to remove seborrheic keratoses for aesthetic reasons, but the growths themselves are harmless.