Squamous Cell Carcinoma

Squamous cell carcinoma (SCC), the second most common skin cancer after basal cell carcinoma accounting for 20% of all skin malignancies. It arises from the epidermis and resembles the squamous cells that comprise most of the upper layers of skin. SCC™s may occur on all areas of the body including the mucous membranes, but are most common in areas exposed to the sun.

Cumulative ultraviolet skin damage due to chronic exposure to sunlight causes most cases of squamous cell carcinoma. That is why tumors appear most frequently on sun-exposed parts of the body: the face, neck, bald scalp, hands, shoulders, arms, and back. The rim of the ear and the lower lip are especially vulnerable to the development of these cancers.

Squamous cell carcinomas may also occur where skin has suffered certain kinds of injury: burns, scars, long-standing sores, sites previously exposed to X-rays or certain chemicals (such as arsenic and petroleum by-products).

Precancerous Conditions that can give rise to SCC™s. Certain precursor conditions, some of which result from extensive sun damage, are worth noting. They are sometimes associated with the later development of squamous cell carcinoma. They include:

  • Actinic, or solar, keratosis. Actinic keratoses are rough, scaly, slightly raised growths that range in color from brown to red and may be up to one inch in diameter. They appear most often in older people.
  • Actinic cheilitis. A type of actinic keratosis occurring on the lips, it causes them to become dry, cracked, scaly, and pale or white. It mainly affects the lower lip, which typically receives more sun exposure than the upper lip.
  • Leukoplakia. These white patches on the tongue or inside of the mouth have the potential to develop into squamous cell carcinoma.
  • Bowen’s disease. This is now generally considered to be a superficial squamous cell cancer that has not yet spread. It appears as a persistent red-brown, scaly patch, which may resemble psoriasis or eczema. If untreated, it may invade deeper structures.

Regardless of appearance, any change in a preexisting skin growth, or the development of a new growth or open sore that fails to heal, should prompt an immediate visit to a physician. If it is a precursor condition, early treatment will prevent it from developing into a squamous cell carcinoma. Often, all that is needed is a simple surgical procedure or application of a topical chemotherapeutic agent.

Warning Signs of Squamous Cell Carcinoma

  • A wart-like growth that crusts and occasionally bleeds.
  • A persistent, scaly red patch with irregular borders that sometimes crusts or bleeds.
  • An open sore that bleeds and crusts and persists for weeks.
  • An elevated growth with a central depression that occasionally bleeds. A growth of this type may rapidly increase in size.