Skin cancer — the abnormal growth of skin cells — most often develops on skin exposed to the sun. But this common form of cancer can also occur on areas of your skin not ordinarily exposed to sunlight.
There are three major types of skin cancer — basal cell carcinoma, squamous cell carcinoma and melanoma.
Check for signs of skin cancer
It’s important to get to know your skin and what is normal for you, so that you notice any changes. Skin cancers rarely hurt and are much more frequently seen than felt.
Develop a regular habit of checking your skin for new spots and changes to existing freckles or moles.
Checking for skin cancer symptoms
Regular examination of the skin for any new or unusual growths, or changes in the size, shape or color of an existing spot, is key to finding and treating skin cancers early. If you find anything suspicious, you should discuss it with your primary care physician or a dermatologist.
While many skin cancers develop in areas exposed to the sun, they may also develop in areas that are usually hidden from the sun. It is important to examine all of these areas. In addition to examining the legs, trunk, arms, face and neck, it is important to look for signs of skin cancer in the areas between the toes, underneath nails, palms of the hands and soles of the feet, genitals and even the eyes.
- Make sure you check your entire body as skin cancers can sometimes occur in parts of the body not exposed to the sun, for example soles of the feet, between fingers and toes and under nails.
- Undress completely and make sure you have good light.
- Use a mirror to check hard to see spots, like your back and scalp, or get a family member, partner or friend to check it for you.
Where skin cancer develops
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 — your palms, beneath your fingernails or toenails, and your 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, such as the palms of the hands and soles of the feet.
Basal cell carcinoma
Basal cell carcinoma usually occurs in sun-exposed areas of your body, such as your neck or face.
Basal cell carcinoma is the most common and easiest-to-treat skin cancer. Because basal cell carcinoma spreads slowly, it occurs mostly in adults. Basal cell tumors can take on many forms, including a pearly white or waxy bump, often with visible blood vessels, on the ears, neck, or face. Tumors can also appear as a flat, scaly, flesh-colored or brown patch on the back or chest, or more rarely, a white, waxy scar.
Basal cell carcinoma may appear as:
- A pearly or waxy bump
- A flat, flesh-colored or brown scar-like lesion
Squamous cell carcinoma
This nonmelanoma skin cancer may appear as a firm red nodule, a scaly growth that bleeds or develops a crust, or a sore that doesn’t heal. It most often occurs on the nose, forehead, ears, lower lip, hands, and other sun-exposed areas of the body. Squamous cell carcinoma is curable if caught and treated early. If the skin cancer becomes more advanced, treatment will depend on the stage of cancer.
Most often, squamous cell carcinoma occurs on sun-exposed areas of your body, such as your face, ears and hands. People with darker skin are more likely to develop squamous cell carcinoma on areas that aren’t often exposed to the sun.
Squamous cell carcinoma may appear as:
- A firm, red nodule
- A flat lesion with a scaly, crusted surface
Bowen disease is also called squamous cell carcinoma “in situ.” It is a type of skin cancer that spreads outward on the surface of the skin. By contrast, “invasive” squamous cell carcinomas can grow inward and spread to the interior of the body. Bowen disease looks like scaly, reddish patches that may be crusted; it may be mistaken for rashes, eczema, fungus, or psoriasis.
Melanoma is not as common as other types of skin cancer, but it’s the most serious and potentially deadly. Possible signs of melanoma include a change in the appearance of a mole or pigmented area. Consult a doctor if a mole changes in size, shape, or color, has irregular edges, is more than one color, is asymmetrical, or itches, oozes, or bleeds.
Melanoma can develop anywhere on your body, in otherwise normal skin or in an existing mole that becomes cancerous. Melanoma most often appears on the face or the trunk 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.
Melanoma signs include:
- A large brownish spot with darker speckles
- A mole that changes in color, size or feel or that bleeds
- A small lesion with an irregular border and portions that appear red, white, blue or blue-black
- Dark lesions on your palms, soles, fingertips or toes, or on mucous membranes lining your mouth, nose, vagina or anus
Signs and symptoms of less common skin cancers
Other, less common types of skin cancer include:
- Kaposi sarcoma. This rare form of skin cancer develops in the skin’s blood vessels and causes red or purple patches on the skin or mucous membranes.Kaposi sarcoma mainly occurs in people with weakened immune systems, such as people with AIDS, and in people taking medications that suppress their natural immunity, such as people who’ve undergone organ transplants.Other people with an increased risk of Kaposi sarcoma include young men living in Africa or older men of Italian or Eastern European Jewish heritage.
- Merkel cell carcinoma. Merkel cell carcinoma causes firm, shiny nodules that occur on or just beneath the skin and in hair follicles. Merkel cell carcinoma is most often found on the head, neck and trunk.
- Sebaceous gland carcinoma. This uncommon and aggressive cancer originates in the oil glands in the skin. Sebaceous gland carcinomas — which usually appear as hard, painless nodules — can develop anywhere, but most occur on the eyelid, where they’re frequently mistaken for other eyelid problems.
Tips for Screening Moles for Cancer
Examine your skin on a regular basis. A common location for melanoma in men is on the back, and in women, the lower leg. But check your entire body for moles or suspicious spots once a month. Start at your head and work your way down. Check the “hidden” areas: between fingers and toes, the groin, soles of the feet, the backs of the knees. Check your scalp and neck for moles. Use a handheld mirror or ask a family member to help you look at these areas. Be especially suspicious of a new mole. Take a photo of moles and date it to help you monitor them for change. Pay special attention to moles if you’re a teen, pregnant, or going through menopause, times when your hormones may be surging.