Squamous Cell Carcinoma
What is it?
Squamous cell carcinoma is a cancer that originates in
the outermost portion of the skin, called the epidermis.
The squamous cells are located here.
Who gets it?
Squamous cell carcinoma of the skin affects over
200,000 Americans each year. It is the second most common
form of skin cancer. Anyone with a substantial history of
sun exposure can develop squamous cell carcinoma. Older
individuals who have fair skin, light hair, and blue,
green, or gray eyes are at the highest risk. People with
occupations that require them to work long hours outdoors
or those who spend extensive leisure time in the sun are
also at high risk. While people of African, Asian, or
Hispanic descent are far less likely than fair-skinned
individuals to develop skin cancer because of the
protective pigment in their skin, they are not without
risk. In fact, those with darker skin are more likely to
have more advanced cases when diagnosed because they
believe they are not at risk.
What causes it?
The majority of squamous cell carcinomas are caused by
chronic sun exposure. Squamous cell carcinomas may also
occur where skin has suffered certain kinds of injury such
as burns, scars, non-healing ulcers, exposure to certain
chemicals (such as arsenic and petroleum by-products), and
radiation. In addition, chronic skin inflammation or
medical conditions that suppress the immune system over an
extended period of time (such as an organ transplant) may
encourage the development of squamous cell carcinoma.
What are the symptoms?
Squamous cell carcinomas may occur on any portion of
the body, including the mucous membranes, but are most
common in the areas that are chronically exposed to the
sun. That is why tumors appear most frequently on
sun-exposed parts of the body: the face, neck, bald scalp,
back of the hands, shoulders, arms, upper back, and chest.
The rim of the ear and the lower lip are especially
vulnerable to the development of these cancers. Squamous
cell carcinoma is usually asymptomatic, meaning there are
no symptoms. Occasionally it may itch, burn, or bleed
after minimal trauma. Most early lesions are flat with a
fine scale or crust. As the lesion progresses, it thickens
and may form a red, firm bump. It may also develop an
elongated crust (horn) that catches on clothing.
How is it diagnosed?
To make a diagnosis of skin cancer, your doctor will
ask you about any medical conditions you might have and
your history of sun exposure. It is important to know if
you have a personal or family history of skin cancer. The
doctor will also ask when you first noted the spot and
whether it has changed in size or appearance. He or she
will perform a skin examination and may also check for
enlarged lymph nodes, which can indicate that a cancer has
spread. If the doctor believes there is any cause for
concern about a particular patch of skin, he or she will
perform a biopsy, in which all or part of the growth is
surgically removed. This is usually done in the doctor's
office with a local anesthetic. The skin that was removed
is then examined under a microscope by a
dermatopathologist to determine if any cancer is present.
If so, the doctor will determine the stage of disease, or
how far it has progressed, in order to determine the best
possible treatment.
What is the treatment?
Most squamous cell carcinomas remain confined to the
skin and are readily cured by a variety of methods.
Treatment options depend upon the tumor's location and
size; the patient's general health, medical history, and
preferences; and whether the tumor has been treated
before. Treatment options may include electrodessication
and curettage (the process of using a tool called a
curette to scrape away cancerous cells and tissues as well
as short, high frequency electric impulses to destroy (dry
up) any remaining cancerous cells and tissues),
cryotherapy (freezing), radiation, standard surgical
excision, or Mohs' micrographic surgery. If left untreated
and allowed to progress, squamous cell carcinomas may
eventually penetrate and destroy the underlying tissues.
In a small percentage of cases, such as those arising in
sites of chronic inflammation or of a very large size, the
cancer may spread (metastasize) and have the potential to
be fatal.
Self-care tips
Because squamous cell carcinomas that recur have a
potential to spread to other parts of the body, it is very
important that they be adequately treated the first time.
You can help protect yourself by having regular exams by a
dermatologist, who can identify suspicious-looking lesions
before they progress too far. If you must spend time in
the sun, make sure you are well protected with a sunscreen
of at least an SPF15, a hat, and protective clothing.
This information has been designed as a comprehensive and quick reference
guide written by our health care reviewers. The health information written
by our authors is intended to be a supplement to the care provided by your
physician. It is not intended nor implied to be a substitute for
professional medical advice.
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