Skin cancer is the most common cancer in the United States. It affects about 1 in 5 Americans during their lifetimes.

Skin cancer is divided into different types based on the type of skin cells it develops in. Symptoms vary between skin cancer types.

For example, melanomas are often dark in color, and squamous cell carcinoma may be red and scaly. However, appearances can vary, even in a specific type of skin cancer, depending on your skin color.

Keep reading to learn about the different types of skin cancer (including precancerous skin conditions), what causes them, what they typically look like, and risk factors.

Actinic keratosis, also known as solar keratosis, is a pre-cancerous growth that appears as a rough patch of skin. It may be pink or red, but can also be flesh-colored or pigmented.

This condition is very common and is caused by chronic exposure to ultraviolet (UV) light found in sunlight. About 75 percent of the time, it appears on parts of your body that are chronically exposed to sunlight, such as the:

  • scalp
  • ears
  • forearms
  • face
  • hands
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Actinic keratosis on the nose. Actinic keratoses are commonly located on sun-exposed areas, such as the face, back of the hands, and scalp.

Risk factors

Risk factors for the development of actinic keratosis include:

  • being older
  • being male
  • having fair skin
  • living close to the equator
  • being exposed to the sun for long periods of time
  • having a family history of actinic keratosis
  • having a compromised immune system


Most dermatologists recommend treating actinic keratosis to keep it from progressing into squamous cell carcinoma.

Treatment options are divided into lesion-directed treatments that target individual spots and field-directed treatments that treat a wide area.

Lesion-directed treatment options include:

Field-directed treatments include:

Basal cell carcinoma is the most common form of cancer in humans, affecting about 20 percent of Americans. It develops in basal cells, which are found at the bottom of the outer layer of your skin called the epidermis.

It usually appears as a raised, pearly or waxy pink bump, often having a dimple in the middle. It can also appear translucent with blood vessels near the skin’s surface.

In some skin types, particularly darker skin types, basal cell carcinoma can also appear to be darker or pigmented.

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Nodular basal cell carcinoma is the most common type of basal cell carcinoma, and it’s characterized by a shiny nodule with rolled edges and a crusted central crater. Photo: DermNet New Zealand

The prime cause of basal cell carcinoma is exposure to UV light, either through sunlight or indoor tanning equipment like tanning beds or lamps. UV light damages the DNA in skin cells and causes them to grow uncontrollably.

About 1 in 5 cases of basal cell carcinoma develop on areas of skin that don’t receive regular sun exposure, suggesting that other causes of DNA damage may also play a role in its development.

Risk factors

Risk factors include:

  • living closer to the equator
  • having fair skin
  • having red hair
  • having had blistering sunburns during childhood
  • having a family history of basal cell carcinoma
  • being exposed to ionizing radiation
  • being exposed to arsenic
  • being immunosuppressed
  • smoking (in women)


Basal cell carcinoma usually isn’t life threatening and rarely spreads to other parts of your body. It’s highly treatable when treatment is started early. The most common treatment option is surgery. Other treatment options include:

  • radiation therapy
  • topical chemotherapy
  • cryosurgery
  • targeted therapy
  • immunotherapy

Squamous cell carcinoma is the second most common type of skin cancer. It develops in squamous cells, which make up the outer layer of your epidermis.

It usually appears as red, scaly, and rough skin sores, typically on sun-exposed areas such as your hands, head, neck, lips, or ears. It can also develop inside of scars or chronic open sores.

Squamous cell carcinoma can also appear darker or pigmented, especially in people with darker skin.

Red patchy sores can also be a sign of the earliest form of the cancer called squamous cell carcinoma in situ (Bowen’s disease).

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Squamous cell carcinoma of the skin is invasive and can spread locally or to other parts of the body. Photo: DermNet New Zealand

The most common cause of squamous cell carcinoma is UV light exposure. Long-term exposure to chemicals that cause cancer such as some chemicals in cigarettes can also lead to its development.

Some types of human papillomavirus (HPV) may also cause squamous cell carcinoma, especially if the cancer develops on the genitals.

Risk factors

Risk factors for squamous cell carcinoma development include:

  • having fair skin
  • having a weakened immune system
  • having a history of skin cancer
  • being over age 50
  • being male
  • having a condition that increases sun-sensitivity
  • having a history of HPV
  • having actinic keratosis


Squamous cell carcinoma is typically more aggressive than basal cell carcinoma and can spread to other body parts if left untreated. It can usually be cured when treated early.

Treatment options include:

  • surgery
  • radiation therapy
  • electronic skin surface brachytherapy (type of radiation therapy)
  • fluorouracil
  • imiquimod

Melanoma occurs in melanocytes, which are skin cells that create pigment. It’s caused by gene changes inside melanocytes that cause the cells to become cancerous. Exposure to UV light and genetic factors play a role in its development.

While overall less common than basal and squamous cell carcinoma, melanoma is by far the most dangerous. It makes up about 1 percent of skin cancers but is responsible for most skin cancer deaths.

Melanoma can start anywhere on your body, such as the chest, neck, legs, and face. It can also occur in areas that don’t typically receive exposure to the sun, such as fingernail beds, the palms of the hands, and the soles of the feet.

Mucosal melanoma can also develop in mucus membranes lining the nose, mouth, and the digestive and urinary tracts.

According to the Skin Cancer Foundation, the 5-year survival rate when caught early is 99 percent, but this drops to 66 percent if it reaches your lymph nodes and 27 percent if it reaches a distant organ.

Melanoma may first appear as changes to an existing mole or as a new mole. Melanoma can be suspected if a mole has any of the “ABCDE” characteristics:

  • Asymmetrical shape
  • Border irregularities
  • Color that isn’t consistent
  • Diameter larger than 6 millimeters
  • Evolving size or shape
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There are several different types of melanoma, with some causing flat patches, as seen in the superficial spreading type, while others may cause nodules. Some melanomas may even be colorless. Photo: DermNet New Zealand

Risk factors

Risk factors for developing melanoma include:

  • being exposed to UV light
  • having many moles or atypical moles
  • having a family history of melanoma
  • having fair skin and light hair
  • having a history of skin cancer
  • having a weakened immune system
  • being older
  • being male
  • having xeroderma pigmentosum


Surgery is usually used to remove early-stage melanoma. Other treatments include:

  • immunotherapy
  • targeted therapy drugs
  • chemotherapy
  • radiation therapy

The four major types of melanoma

Melanoma can be divided into different subtypes. A few of the most common subtypes are:

  • Superficial spreading melanoma. Superficial spreading melanoma is the most common type of melanoma. Lesions are usually flat, irregular in shape, and contain varying shades of black and brown. It can occur at any age.
  • Lentigo maligna melanoma. Lentigo maligna melanoma usually affects adults over 65 and involves large, flat, brownish lesions.
  • Nodular melanoma. Nodular melanoma can be dark blue, black, or reddish-blue, but may have no color at all. It usually starts as a raised patch.
  • Acral lentiginous melanoma. Acral lentiginous melanoma is the least common type. Typically it affects the palms, soles of the feet, or under finger and toenails.

Kaposi’s sarcoma is a type of cancer that involves skin lesions that are brownish-red to blue in color and usually found on the legs, feet and face.

The skin lesions can also be found on the genitals and in the mouth. Kaposi’s sarcoma can also affect lymph nodes and internal organs. It affects the cells that line lymph or blood vessels close to the skin.

This cancer is caused by a type of herpes virus, typically in people with weakened immune systems such as those with AIDS or those taking immunosuppressant drugs after an organ transplant.

There are other, less commonly thought of types of Kaposi’s sarcoma, including those that occur in older men of Eastern European, Mediterranean, and Middle Eastern descent, and a type that occurs in equatorial Africa.

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Though Kaposi’s sarcoma starts with flat patches, it develops into scaly plaques, nodules, or tumors. Photo: DermNet New Zealand

Risk factors

Risk factors for Kaposi’s sarcoma development include:

  • being of Jewish, Mediterranean, or equatorial African descent
  • being male
  • having a human herpesvirus 8 infection
  • having a weakened immune system
  • living with AIDS


Six types of treatment are used as standard treatment:

About 80 to 90 percent of people with the classic form of Kaposi’s sarcoma survive, but many people develop a secondary cancer.

While there are several different types of skin cancers, most share the same risk factors, including:

  • being exposed to UV rays found in sunlight and tanning equipment for long periods
  • being over the age of 40
  • having a family history of skin cancer
  • having a fair complexion
  • being immunocompromised

Even though it’s less common, young people and people with dark complexions can still develop skin cancer. It’s important to see a dermatologist for a proper diagnosis if you notice any new skin spots that could be cancerous.

The quicker skin cancer is detected, the better the long-term outlook. Learn how to self-examine your skin.

Skin cancer is the most common type of cancer in the United States. The appearance of skin cancer can vary widely and depends on the type of cells affected. It’s important to visit a dermatologist if you notice any abnormal spots that could be cancerous.

Taking preventive measures to avoid UV rays, such as wearing sunscreen or limiting your time in the sun, can help prevent against all types of skin cancer.