Squamous Cell Skin Cancer

Bowen’s Disease
Bowen’s Disease


Squamous cell cancer is the second most common type of cancer in the United States.

Other common types of skin cancer are:

Commonly Associated With

Cancer – skin – squamous cell; Skin cancer – squamous cell; Nonmelanoma skin cancer – squamous cell; NMSC – squamous cell; Squamous cell skin cancer; Squamous cell carcinoma of the skin


Squamous cell skin cancer affects the epidermis, the top layer of skin.

Squamous cell cancer may occur in undamaged skin. It can also occur in skin that has been injured or inflamed. Most squamous cell cancers occur on skin that is regularly exposed to sunlight or other ultraviolet radiation.

The earliest form of squamous cell cancer is called Bowen disease (or squamous cell carcinoma in situ). This type does not spread to nearby tissues, because it is still in the outermost layer of the skin.

Actinic keratosis is a precancerous skin lesion that may become squamous cell cancer. (A lesion is a problem area of the skin.)

A keratoacanthoma is a mild type of squamous cell cancer that grows rapidly.

Risks of squamous cell cancer include:

  • Having light-colored skin, blue or green eyes, or blond or red hair.
  • Long-term, daily sun exposure (such as in people who work outside).
  • Many severe sunburns early in life.
  • Older age.
  • Having had many x-rays.
  • Chemical exposure, such as arsenic.
  • A weakened immune system, especially in persons who have had an organ transplant.


Squamous cell cancer usually occurs on the face, ears, neck, hands, or arms. It may occur in other areas.

The main symptom is a growing bump that may have a rough, scaly surface and flat reddish patches.

The earliest form (squamous cell carcinoma in situ) can appear as a scaly, crusted, and large reddish patch that can be larger than 1 inch (2.5 centimeters).

A sore that does not heal can be a sign of squamous cell cancer. Any change in an existing wart, mole, or other skin lesions could be a sign of skin cancer.

Exams & Tests

Your doctor will check your skin and look at the size, shape, color, and texture of any suspicious areas.

If your doctor thinks you might have skin cancer, a piece of skin will be removed. This is called a skin biopsy. The sample is sent to a lab for examination under a microscope.

A skin biopsy must be done to confirm squamous cell skin cancer or other skin cancers.


Normally you don’t want to drain a blister, because of the risk of infection. But if a blister is large, painful, or looks like it will pop on its own, you can drain the fluid.


Courtesy of MedlinePlus from the National Library of Medicine