Skin cancer develops primarily on areas of sun-exposed skin, including the scalp, face, lips, ears, neck, chest, arms and hands, and on the legs in women. But it can also form on areas that rarely see the light of day — the palms, beneath fingernails or toenails, and the genital area.
Skin cancer affects people of all skin tones, including those with darker complexions. When melanoma occurs in people with dark skin tones, it's more likely to occur in areas not normally exposed to the sun.
Basal cell carcinoma
Basal cell carcinoma usually occurs in sun-exposed areas of the body, such as the neck or face and may appear as:
- A pearly or waxy bump which can become an ulcerated sore
- A flat, pink patch which may bleed when rubbed
- Irregular pigmentation especially in people with darker skin
Squamous cell carcinoma
Most often, squamous cell carcinoma occurs on sun-exposed areas of the body, such as the face, ears and hands. People with darker skin are more likely to develop squamous cell carcinoma on areas that aren't often exposed to sun, such as the legs and feet.
Squamous cell carcinoma may appear as:
- A firm, red nodule often tender and with a central core
- A flat pink lesion with a scaly or crusted surface
Melanoma can develop anywhere on the body, in otherwise normal skin or in an existing mole that becomes cancerous. Melanoma most often appears on the trunk, head or neck of affected men. In women, this type of cancer most often develops on the lower legs. In both men and women, melanoma can occur on skin that hasn't been exposed to the sun.
Melanoma can affect people of any skin tone. In people with darker skin tones, melanoma tends to occur on the palms or soles, or under the fingernails or toenails.
Watch for the 3 Cs of Malignant Melanoma
- Color – most melanomas have different shades of black and brown, with occasionally red, white and blue pigmentation.
- Contour – most melanomas have irregular contour, which refers to the shape and border. The surface contour may also become irregular with time. Some may be asymmetrical with one half looking different from the other.
- Change – most melanomas exhibit change over time in size, color or contour. They especially look out of proportion to other existing moles. Change can also include itching, bleeding and crusting.
Any worrisome changes to the skin should be examined by the doctor. Not all skin changes are caused by skin cancer. A doctor will investigate skin changes to determine a cause.
To diagnose skin cancer, a doctor may:
- Examine your skin
- Remove a sample of suspicious skin for testing (skin biopsy)
- Determine the extent of the skin cancer
Skin cancer is classified by stage. Stage helps determine which treatment options will be most effective. Small skin cancers limited to the surface of the skin may not require treatment beyond an initial skin biopsy that removes the entire growth.
If additional treatment is needed, the cancer team may recommend:
- Cryosurgery—the doctor may destroy some small, early skin cancers by freezing them with liquid nitrogen. The dead tissue sloughs off as it heals from the procedure.
- Excisional surgery—This type of treatment may be appropriate for any type of skin cancer. Your doctor removes the cancerous tissue and a surrounding margin of healthy skin. A wide excision — removing extra normal skin around the tumor — may be recommended in some cases.
- Laser therapy—A precise, intense beam of light vaporizes growths, generally with little damage to surrounding tissue. A doctor may use this therapy to treat superficial skin cancers.
- Curettage and electrodesiccation—After removing most of a growth, the doctor scrapes away layers of cancer cells using a circular blade (curette). An electric needle destroys any remaining cancer cells. This simple, quick procedure may be used to treat small or thin basal cell cancers or squamous cell cancers.
- Mohs surgery—This procedure is for larger, recurring or difficult-to-treat skin cancers, which may include both basal and squamous cell carcinomas. The physician removes the skin growth layer by layer, examining each layer under the microscope, until no abnormal cells remain. This procedure allows cancerous cells to be removed without taking an excessive amount of surrounding healthy skin. The Mohs surgeon or a plastic surgeon will usually repair the resulting defect, often with a skin flap or graft.
- Radiation therapy—Radiation may be used in situations when surgery isn't an option. The skin cancer is destroyed gradually. Radiation therapy may be used in combination with other types of therapy to treat aggressive or recurrent skin cancer. It is often used when a patient cannot have other procedures because of age or health problems, when the cancer is deep, hard to reach or recurrent or to relieve symptoms.
- Chemotherapy—In chemotherapy, drugs are used to kill cancer cells. For cancers limited to the top layer of skin, creams or lotions containing anti-cancer agents may be applied directly to the skin. Systemic chemotherapy can be used to treat skin cancers that have spread to other parts of the body.
- Photodynamic therapy (PDT) —This treatment destroys skin cancer cells with a combination of visible or laser light and drugs that makes cancer cells sensitive to light. PDT makes the skin sensitive to light, so patients need to avoid direct sunlight for at least six weeks after treatment.
- Biological therapy—Biological treatments stimulate the immune system in order to kill cancer cells. Biological therapy medications used to treat certain skin cancer include interferon, interleukin-2 and topical immquimod cream.
- Chemotherapy – two new drugs for metastatic melanoma have recently been approved and result in increased survival. Ipilimumab or yervoy stimulates the immune system and Vemurafinib or relboraf attacks the melanoma cells.