The information on this page was reviewed and approved by
Maurie Markman, MD, President, Medicine & Science at CTCA.

This page was updated on September 21, 2021.

Squamous cell carcinoma

Squamous cell carcinoma (SCC) is one of the most common types of skin cancer. This cancer starts in the flat squamous cells found in the upper part of the epidermis, the skin’s outermost layer. About two out of 10 skin cancers are squamous cell carcinomas, according to the American Cancer Society.

Symptoms of squamous cell carcinoma

Knowing the signs and symptoms may help you identify squamous cell carcinoma in its most treatable stages.

These include:

  • Sore that won’t heal and has a raised border
  • Rough, reddish, scaly patch of skin
  • Dome-shaped growth
  • Small horn-shaped growth on skin
  • Sore in an old scar
  • Wart-like sore on nails or genitals
  • Brown or black line under fingernail or toenail
  • Sore inside your mouth
  • Single colored mark (it may be red, pink, brown, black, yellow or white)

Squamous cell carcinoma may also itch or feel sore. Some patients report numbness or tingling in the area.

This type of skin cancer typically appears on sun-exposed parts of the body, such as the face, ears, neck, lips or the backs of hands. Sometimes it forms in a scaly patch of skin called actinic keratosis or AK, which is caused by sun exposure.

Risk factors and causes

Exposure to the sun's ultraviolet (UV) rays is the leading cause of squamous cell carcinoma and other skin cancers. The UV rays damage the DNA, or genetic material, in the squamous cells, increasing the risk for cancer.

Other factors that may raise your risk include:

  • History of sunburns or using tanning beds
  • Location of residence: Living at a high altitude or in a very sunny region
  • Weakened immune system
  • Age (older than 50)
  • Gender: Being male
  • Fair skin
  • Previous radiation treatment
  • Precancerous skin conditions
  • Human papillomavirus (HPV)

In people with a darker skin tone, these skin cancers tend to develop in areas that get little or no sun, including the mouth, genitals or anus.

Early diagnosis

The best way to stay a step ahead of all types of skin cancer, including squamous cell carcinoma, is to schedule yearly visits with a dermatologist. During a skin check, a dermatologist looks for any abnormal area that differs in color, size, shape or texture from the skin around it.

In addition to doctor visits, monthly self-exams are recommended. Patients who spot something suspicious that’s growing, bleeding or changing should consult with their dermatologist for follow-up. If needed, the doctor may perform a biopsy and send the cells to the lab for analysis to determine if they’re cancerous.

Treatment for squamous cell carcinoma

Squamous cell carcinoma treatment is based on the size and location of the growth, as well as the patient’s overall health.


Squamous cell carcinoma is often removed surgically via excision (the doctor cuts out the tumor and stitches up the skin). Another method, curettage and electrodesiccation, scrapes away cancer cells and uses electricity to kill remaining cancer cells.

Mohs micrographic surgery, a more involved procedure, is often used for aggressive, large or recurrent squamous cell cancers. It may be an option for squamous cell carcinoma that’s spreading along nerves, or on the face or genital area. The surgeon removes the cancer, followed by a thin layer of surrounding skin, which is examined under a microscope for cancer cells. If cancer cells are still present, the surgeon removes another layer. This process continues until no cancer cells are detected.

If spread is suspected, the doctor may remove nearby lymph nodes.

Nonsurgical options

There are nonsurgical options for treating squamous cell carcinoma, too, including radiation therapy, which uses X-ray energy to kill cancer cells and shrink tumors. Radiation therapy may be recommended if: 

  • All of the cancer wasn’t removed during surgery.
  • The cancer has returned.
  • Nerves are involved.

Other options may include: