Melanoma

Squamous cell cancer

Squamous cell cancer is the second most frequent type of skin cancer. It arises from the outer keratinizing layer of skin, so named because it contains a tough protein called keratin. Squamous cell cancer grows faster than basal cell cancer; it is more likely to metastasize to the lymph nodes as well as to distant sites. Squamous cell cancer most often appears on the arms, head, and neck. Fair-skinned people of Celtic descent are at high risk for developing squamous cell cancer. This type of cancer is rarely life-threatening but can cause serious problems if it spreads and can also cause disfigurement. Squamous cell cancer usually appears as a scaly, slightly elevated area of damaged skin.

Other skin cancers

Besides the three major types of skin cancer, there are a few other relatively rare forms. The most serious of these is Kaposi's sarcoma (KS), which occurs primarily in persons who have AIDS or older males of Mediterranean descent. When KS occurs with AIDS it is usually more aggressive. Other types of skin tumors are usually nonmalignant and grow slowly. These include:

• Bowen's disease. This is a type of skin inflammation (dermatitis) that sometimes looks like squamous cell cancer.
• Actinic or solar keratosis. This is a sunlight-damaged area of skin that sometimes develops into cancer.
• Keratoacanthoma. A keratoacanthoma is a domeshaped tumor that can grow quickly and appear like squamous cell cancer. Although it is usually benign, it should be removed.

Risk factors

SUN EXPOSURE. Most skin cancers are associated with the amount of time that a person spends in the sun and the number of sunburns received, especially if they occurred at an early age. Skin cancer typically does not appear for 10-20 years after the sun damage has occurred. Because of this time lag, skin cancer rarely occurs before puberty and occurs more frequently with age.

MOLES. The number of moles (nevi) on a person's skin is related to the likelihood of developing melanoma. There are three types of nevi: not cancerous (benign); atypical (dysplastic); or birthmark (congenital). All three types of nevi have been associated with a higher risk of developing melanoma. Sometimes the moles themselves can become cancerous. Usually, however, the cancer is a new growth that occurs on normal skin.

HEREDITY.The tendency to develop skin cancer also tends to run in families. As has already been mentioned, there appears to be a significant genetic factor in the development of melanoma.

Content licensed from:

Author Info: L. Fleming Fallon Jr., M.D., Dr.P.H., The Gale Group Inc., Gale, Detroit, Gale Encyclopedia of Nursing and Allied Health, 2002

This feature is for informational purposes only and should not be used to replace the care and information received from your healthcare provider. Please consult a healthcare professional with any health concerns you may have.