Squamous Cell Carcinoma: Types, Symptoms, Causes, Risks, Complications, Diagnosis, Treatment and Outlook

A skin of a man with symptoms of squamous cell carcinoma


The skin is the largest organ in the body and it plays a pivotal role in protecting the internal parts of the body. It acts as the body’s first line of defense against environmental hazards, disease-causing microorganisms and other elements that may bring disease to the body.

However, the skin may also experience disease. One of the diseases that can affect the skin is cancer. There are many types of skin cancer and one of the most common forms is squamous cell carcinoma. This disease develops in the squamous cells that make up the middle and outer layer of the skin.

Squamous cell carcinoma can occur in the other parts of the body such as the organs of the respiratory tract and digestive tract. Cancer spreads and develops in the lining of the hollow organs in the body, particularly in the digestive and respiratory tract.

Squamous cell carcinoma (SCC) of the skin is the second most common form of skin cancer. It is described as the uncontrolled growth of abnormal cells coming from the squamous cells. The squamous cells are mainly found in the epidermis, the skin’s upper layer.

This type of cancer looks like scaly red patches, elevated lesions with a central depression warts, and open sores. They may crust or bleed and if they grow too much, they can become deadly. However, most squamous cell carcinomas are not life-threatening.

Squamous cell carcinomas can occur in any part of the body but are most commonly seen in areas that are exposed to the sun. These areas include the lower lip, balding scalp, hands, neck, arms, and legs.

More than one million squamous cell carcinoma cases are diagnosed in the United States every year. Approximately 8,800 individuals die from the disease and the incidence increased over the past three decades by about 200 percent. This is due to the increasing heat and sun exposure due to climate change.


The types of squamous cell carcinoma include:

  • Squamous cell carcinoma of the skin
  • Squamous cell carcinoma of the lung
  • Squamous cell carcinoma of the thyroid
  • Esophageal Squamous cell carcinoma


Focusing on the skin cancer type of squamous cell carcinoma, the signs and symptoms include:

  • A red and firm nodule
  • New sore or elevated area on an old scar or ulcer
  • Flat sore with a scaly crust
  • Red sore or rough patch in the mouth
  • Rough and scaly patch on the lips

These lesions are usually found in areas that are exposed to ultraviolet radiation such as the ears, face, back of the neck and hands. It can also appear on the mouth, genitals and anal area.

In the early stages of the condition, squamous cell carcinoma may look reddish and scaly. As it worsens and progresses, it can turn into a raised or elevated bump that continues to grow and spread.

In some cases, the growth may crust or bleed. In the mouth, however, the lesion may look like a mouth ulcer or a white patch.


Skin cancer is caused by the mutation in the skin cell’s DNA. These changes may lead to the abnormal cells to spread and multiply uncontrollably. When this happens in the skin,
it may lead to squamous cell carcinoma.

Squamous cell carcinoma of the skin may be caused or triggered by the damage to the DNA in skin cells because of ultraviolet (UV) radiation. This is usually found in sunlight and tanning beds and lamps. However, sun exposure alone can’t explain skin cancers that develop in areas which are not exposed to the sun. This shows that there are other factors that may contribute to the increased risk of developing squamous cell carcinoma of the skin.

5Risk Factors

Some people are at a higher risk of developing squamous cell carcinoma:

People with fair skin – People who have fair skin, light hair and blue, green or gray eyes are at a higher risk of developing squamous cell carcinoma.

Excessive exposure to the sun – People who are exposed to UV light from the sun may increase the risk of developing the disease. This applies to those who spend a lot of time under the sun without protection or work in areas where there is an open space.

Use of tanning lights and beds – People who are fond of using tanning beds and lights may have a heightened risk of having this type of skin cancer.

History of skin cancer – People who have previous skin cancers are at a higher risk of developing squamous cell carcinoma. Also, people with a history of sunburns and pre-cancerous skin lesions may also have a higher risk of having SCC.

Compromised immune system – People with weakened immune systems like those who have lymphoma or leukemia, may have increased risks of developing SCC and other skin cancers.

Xeroderma pigmentosum – People with this rare genetic disorder may increase the risk of developing skin cancer. This disease causes extreme sensitivity to sunlight.

The other risk factors include:

  • Having a history of multiple severe sunburns, particularly those which happened during childhood.
  • Living in sunny regions or high altitude areas
  • History of arsenic chemical exposure
  • Previous diagnosis of any skin cancer
  • Older age
  • Moles present at birth or congenital nevi
  • Repeated exposure to radiation
  • Dysplastic nevi (atypical moles)
  • Human papillomavirus (HPV) infection
  • Tobacco use or smoking
  • Leukoplakia or Bowen’s disease
  • Exposure to arsenic, coal tar, and other industrial chemicals.


If squamous cell carcinoma remains untreated, it can damage the surrounding healthy tissue and skin. In fact, the cancer cells can also spread to the lymph nodes and other organs of the body. However, this case is not common.

The cases of deadly and aggressive squamous cell carcinoma are when the lesion is large, deep and if it affects mucous membranes such as the lips. Also, SCC may lead to serious complications when the person affected has a weakened immune system and those who had just undergone an organ transplant.


Tests and procedures that are used to diagnose squamous cell carcinoma of the skin include the following.

Physical examination – During the physical assessment, the doctor will examine the skin for signs of squamous cell carcinoma lesions.

Medical history taking – The doctor will ask questions about the patient’s health history, exposure to the sun and family history of skin cancer.

Removing samples of tissue – To confirm the diagnosis of SCC, the doctor will remove some suspicious skin lesion and it will be examined under a microscope. This is called biopsy.


Squamous cell carcinoma of the skin can be removed with just minor surgery and in some cases, through the use of topical agents.

The most common treatment options include:

Curettage and cryotherapy – This procedure entails the removal of the skin lesion through curettage. The edges and base of the lesion are then treated with liquid nitrogen.

Laser – Laser therapy uses a beam of light that has the ability to vaporize growths. Usually, this procedure has a lesser risk of bleeding, scarring, and inflammation.

Electrodesiccation and curettage (ED and C) – This procedure involves the removal of the surface of the skin cancer lesion with a cure. The base is then seared with an electric needle.

Cryosurgery (Freezing) – This procedure entails the freezing of cancer cells with liquid nitrogen.

Medicated topical creams – These products are used for superficial cancers containing anti-cancer medications.

Photodynamic therapy – This therapy is both the combination of light and photosensitizing drugs to treat skin cancers that are superficial.

Excision – In some cases, the doctor may perform an excision of the lesion and it will be tested through the use of a biopsy.

Radiation therapy – Another treatment is radiation therapy which uses high-energy beams to attack, target and kill cancer cells.


Squamous cell carcinoma of the skin is preventable:

  • Avoid sun exposure during the middle of the day between 10 a.m. and 4 p.m.
  • Wear sunscreen every day, all-year-round. Make sure it’s a broad spectrum sunscreen with a minimum of 30 sun protection factor (SPF)/
  • Reapply sunscreen every two hours
  • Stay in the shade
  • Wear protective clothing especially when you’re going to be exposed to the sun
  • Avoid using tanning beds and lights
  • Check the skin regularly and seek medical help for certain skin changes.
  • Limit the sun exposure
  • Use umbrellas or caps when going under the sun
  • Wear glasses with UV protection
  • Protect your skin even during summer because winter rays are dangerous, too.
  • See a dermatologist once a year for a full-body skin assessment.


Squamous cell carcinoma is not that dangerous, if it’s detected early and treated promptly and appropriately. Early detection of squamous cell carcinoma is the key to a successful treatment of the condition. If the SCC is not treated during its early stages, cancer may spread to the other healthy tissues and areas of the body, such as the organs and lymph nodes. If cancer spread occurs, this may lead to life-threatening complications.

Those with weakened and compromised immune systems due to certain medical issues such as HIV, AIDS, and leukemia are at a higher risk of developing more severe forms of squamous cell carcinoma.