Squamous cell cancer

Alternative names
Cancer - skin - squamous cell; Skin cancer - squamous cell

Squamous cell cancer is a malignant tumor that affects the middle layer of the skin.

Causes, incidence, and risk factors

Any change in an existing wart, mole or other skin lesion, or the development of a new growth that ulcerates and does not heal well, could indicate skin cancer. Skin cancer has a high cure rate if it is treated early, but neglect can allow the cancer to spread, causing disability or death.

Over 90% of skin cancers occur on areas of the skin that are regularly exposed to sunlight or other ultraviolet radiation. This is considered the primary cause of all skin cancers.

Other risks include older age, genetic predisposition (skin cancers are more common in those who have light-colored skin, blue or green eyes, and blond or red hair), chemical pollution, and overexposure to x-rays or other forms of radiation. Exposure to arsenic, which may be present in some herbicides, is another risk for development of skin cancers.

Squamous cell cancer is a malignant tumor. It is more aggressive than basal cell cancer, but still may be relatively slow-growing. It is more likely than basal cell cancer to spread (metastasize) to other locations, including internal organs. The incidence of skin cancer has increased greatly. In 1990, 600,000 Americans were diagnosed with either basal cell cancer or squamous cell cancer, up from 400,000 in 1980.

Squamous cell cancer involves cancerous changes to the cells of the middle portion of the epidermal skin layer. It is usually painless initially, but may become painful with the development of ulcers that do not heal. This cancer may begin in normal skin - in the skin of a burn, injury, or scar - or at a site of chronic inflammation (which may occur with many skin disorders). It most often originates from sun-damaged skin areas, such as actinic keratosis. It usually begins after age 50.


  • Skin lesion, growth, or bump       o Small       o Firm       o Reddened       o Nodule or flat growth       o Growth may be cone-shaped       o Surface may be scaly or crusted       o Usually located on the face, ears, neck, hands, arms       o May occur on the lip, mouth, tongue, genitals or other areas

Signs and tests
The appearance of the skin lesion may indicate a squamous cell carcinoma. A biopsy and examination of the lesion confirms the diagnosis.


The treatment varies with the tumor’s size, depth, location and how much it has spread (metastasis).

Surgical removal of the tumor, which may include removal of the skin around the tumor (wide excision), is often recommended. Microscopic shaving (Mohs’ surgery) may remove small tumors. Skin grafting may be needed if wide areas of skin are removed.

The tumor may be reduced in size by radiation treatments.

Chemotherapy can be used if surgery and radiation fail, but it is usually minimally effective.

Expectations (prognosis)
Most (95%) of squamous cell tumors may be cured if removed promptly. New tumors may develop, so affected individuals should be diligent about examining the skin. Regular examination by the health care provider is usually required.


  • Local spread of the tumor  
  • Metastasis to other locations, including the internal organs

Calling your health care provider
Call for an appointment with your health care provider if any change in color, size, texture, or appearance of a skin lesion develops. Also call if there is pain, inflammation, bleeding, or itching of an existing skin lesion.

Minimize sun exposure. Protect skin from the sun by wearing protective clothing such as hats, long-sleeved shirts, long skirts or pants. Sunlight is most intense at mid-day, so try to avoid exposure during these hours. Use high-quality sunscreens, preferably with SPF (sun protection factor) ratings of at least 15. Apply the sunscreen at least a half hour before exposure and re-apply frequently. Use a sunscreen throughout the year, even for winter sun exposure.

Examine the skin regularly for development of suspicious growths or changes in an existing skin lesion. A new growth that ulcerates or is slow to heal is suspicious.

Suspicious changes in an existing growth includes a change in color, size, texture, and appearance, or development of pain, inflammation, bleeding, or itching.

A lesion that is asymmetrical, has irregular or diffuse borders, has multiple colors mixed in one lesion, or is larger than 6 mm (millimeters) diameter is suspicious.

Johns Hopkins patient information

Last revised: December 6, 2012
by Dave R. Roger, M.D.

Medical Encyclopedia

  A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | 0-9

All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.