Squamous Cell Carcinoma: Symptoms, Causes & Treatment

Squamous cell carcinoma is a type of skin cancer that starts in the outermost layer of the skin. It usually appears on parts of the body that get the most sun exposure, such as the face, neck, arms, or legs.

This type of cancer is also known as epidermoid carcinoma. It can cause symptoms such as a rough red or brown patch and a sore that does not heal.

Treatment for squamous cell carcinoma depends on the size, location, and depth of the tumor, as well as the person’s overall health. It is important to see a dermatologist if a new spot appears on the skin, keeps growing over time, or causes symptoms such as pain or tingling.

Main symptoms

The main symptoms of squamous cell carcinoma are:

• A firm, red nodule

• A sore with a scaly crust

• Pain and roughness in an old scar or ulcer

Squamous cell carcinoma most often develops on areas of skin that get a lot of sun, such as the scalp, hands, ears, and lips.

It can appear as a rough, scaly patch on the lip that may turn into an open sore, a painful or rough red sore inside the mouth, or a wart-like sore on the anus or genitals.

Squamous cell carcinoma in situ

Also known as Bowen’s disease, squamous cell carcinoma in situ is the earliest stage of squamous cell skin cancer. This means the cancer cells are still limited to the top layer of the skin and have not reached deeper layers.

Squamous cell carcinoma in situ is characterized by symptoms such as red or brown plaques or patches on the skin. These lesions may cause pain, itching, or sensitivity in the affected area.

Confirming a diagnosis

Squamous cell carcinoma is diagnosed by a dermatologist based on a person’s signs and symptoms and a careful examination of any skin nodules or sores.

In many cases, part of the lesion may be removed and sent to a laboratory. This helps confirm the diagnosis.

Possible causes

Squamous cell carcinoma of the skin mainly happens due to long-term sun exposure or the use of tanning beds. It can also develop in areas of skin that were previously damaged, such as burns, scars, ulcers, or old wounds, as well as in skin that was exposed in the past to X-rays or certain chemicals.

In addition, it may arise in people who have long-standing skin infections or inflammation, or in those with weakened immune systems. The National Cancer Institute notes that prior radiation exposure and chronic skin inflammation are recognized risk factors for squamous cell carcinoma.

Risk factors

Factors linked to a higher risk of developing squamous cell carcinoma include:

• Having light skin and hair or blue, green, or gray eyes

• Frequent sun exposure, especially during the hottest hours of the day

• A history of basal cell carcinoma

• Having a condition called xeroderma pigmentosum

• Being older than 50

In addition, squamous cell carcinoma is more common in men than in women.

Treatment options

The treatments recommended for squamous cell carcinoma include:

1. Mohs surgery

Mohs surgery involves removing the visible part of the tumor, which is then examined in a laboratory.

The procedure is repeated until the last piece of tissue removed no longer contains tumor cells.

After the tumor is removed, the wound may heal on its own or be repaired with plastic surgery.

2. Excisional surgery

In this procedure, all of the cancerous tissue is removed along with a border of healthy skin around the lesion as a safety margin.

The wound is closed with stitches, and the removed tissue is sent for analysis to check whether all cancer cells were removed.

3. Curettage and electrodesiccation (ED&C)

In this procedure, the cancer is scraped off with an instrument called a curette. Then an electrocautery needle is used to destroy malignant cells and control bleeding.

This procedure is usually repeated several times to make sure all cancer cells have been eliminated.

It is not considered effective for more invasive or aggressive carcinomas or for cancer in critical areas such as the eyelids, genitals, lips, and ears.

4. Cryosurgery

In cryosurgery, the tumor is destroyed by freezing the tissue with liquid nitrogen, without the need for incisions or anesthesia.

The procedure may need to be repeated several times to make sure all malignant cells are destroyed.

This method is not commonly used for more invasive cancers because it is less effective in deeper parts of the tumor.

5. Radiation therapy

Radiation therapy uses targeted high-energy radiation directed at the lesion, so anesthesia and incisions are not required. Treatment typically involves a series of sessions given multiple times over about one month.

Based on American Academy of Dermatology guidance, radiation therapy may be used for selected squamous cell carcinomas when surgery is not the best option, although surgical treatment is generally considered the most effective approach for cutaneous squamous cell carcinoma.

6. Photodynamic therapy

Photodynamic therapy is more commonly used in people whose cancer develops on the face or scalp.

In this procedure, 5-aminolevulinic acid is applied to the lesions, and the next day a strong light is used.

This treatment destroys cancer cells without damaging normal tissue.

7. Laser surgery

In this technique, a laser is used to remove the outer layer of skin and varying amounts of deeper skin without causing bleeding.

The risks of scarring and pigment loss are slightly higher than with other techniques, and recurrence rates are similar to those seen with photodynamic therapy.