Squamous Cell Carcinoma

Squamous cell carcinoma is the second most common form of skin cancer. It begins in the squamous cells in the outer layer of the skin (epidermis).

CAUSES

Ultraviolet light exposure is the most common cause of squamous cell carcinoma. This may come from sunlight or tanning beds. Squamous cell carcinoma is most common in sun-exposed areas like the face, neck, arms, and hands. However, squamous cell carcinoma can occur anywhere on the body, including the lips, inside the mouth, the legs, sites of long-term (chronic) scarring, and the anus.

Other causes of squamous cell carcinoma can include:

  • Exposure to arsenic.

  • Exposure to radiation.

  • Exposure to toxic tars and oils.

RISK FACTORS

Factors that increase your risk for squamous cell carcinoma include:

  • Having fair skin.

  • Being middle-aged or elderly.

  • Heavy sun exposure, especially during childhood.

  • Repeated sunburns.

  • Use of tanning beds.

  • A weakened immune system. This includes patients who have received a transplant and patients with human immunodeficiency virus (HIV) or acquired immunodeficency syndrome (AIDS).

  • Human papillomavirus infection.

  • Conditions that cause chronic scarring. This can include burn scars, chronic ulcers, heat (thermal) injuries, and radiation.

  • Exposure to psoralen plus ultraviolet A light therapy.

  • Exposure to chemical carcinogens, such as tar, soot, and arsenic.

  • Chronic, inflammatory conditions such as lupus, lichen planus, or lichen sclerosus.

  • Chronic infections, such as infections of the bone (osteomyelitis).

  • Smoking.

SYMPTOMS

Squamous cell carcinoma often starts as small, skin-colored (pink or brown) sandpaper-like growths. These growths are called solar keratoses or actinic keratoses. These growths are often more easily felt than seen.

DIAGNOSIS

Your caregiver may be able to tell what is wrong by doing a physical exam. Often, a tissue sample is also taken. The tissue sample is examined under a microscope.

TREATMENT

The treatment for squamous cell carcinoma depends on the size and location of the tumors, as well as your overall health. Possible treatments include:

  • Mohs surgery. This is a procedure done by a skin doctor (dermatologist or Mohs surgeon) in his or her office. The cancerous cells are removed layer by layer.

  • Laser surgery to remove the tumor.

  • Freezing the tumor with liquid nitrogen (cryosurgery).

  • Radiation. This may be used for tumors on the face.

  • Electrodesiccation and curettage. This involves alternately scraping and burning the tumor, using an electric current to control bleeding.

If treated soon enough, squamous cell carcinoma rarely spreads to other areas of the body (metastasizes). If left untreated, however, squamous cell carcinoma will destroy the nearby tissues. This can result in the loss of a nose or ear.

PREVENTION

  • Avoid the sun between 10:00 am and 4:00 pm when it is the strongest.

  • Use a sunscreen or sunblock with sun protection factor 30 or greater.

  • Apply sunscreen at least 30 minutes before exposure to the sun.

  • Reapply sunscreen every 2 to 4 hours while you are outside, after swimming, and after excessive sweating.

  • Always wear protective hats, clothing, and sunglasses with ultraviolet protection.

  • Avoid tanning beds.

HOME CARE INSTRUCTIONS

  • Avoid unprotected sun exposure.

  • Do not smoke.

  • Follow your caregiver's instructions for self-exams. Look for new growths or changes in your skin.

  • Keep all follow-up appointments as directed by your caregiver.

SEEK MEDICAL CARE IF:

  • You notice any new growths or changes in your skin.

  • You have had a squamous cell carcinoma tumor removed and you notice a new growth in the same location.