Squamous cell carcinoma is a skin cancer that begins in the squamous cells on the surface of skin. Squamous cells are thin, flat cells. They have an appearance of fish scales, when looked under the microscope. Squamous cells form tissues on the surface of skin. They are also found in tissues of the lining of the hollow organs of the body, respiratory passages and digestive tracts. Squamous cell carcinoma can affect any tissue made up of squamous cells.

It is the second most common skin cancer after Basal Cell Carcinoma. People with fairer or light colored skin are at higher risk of developing this disease. Men are more prone to this disease compared to women. People with hair covering their ear are at lower risk of developing this disease around ear.


It starts with pre-cancerous spots known as actinic or solar keratosis. Actinic keratosis is rough, red bumps. They can develop on the scalp, face, ears, and backs of the hands. They are large in size and are capable of easily turning into squamous cell carcinoma after invading deep into the skin. It may take years to develop this disease. A tender and thicker actinic keratosis increases the risk of this disease.

Squamous cell carcinomas can easily spread to other parts of the body. It starts as skin-colored or red firm nodules. Squamous cell cancers starting with solar keratosis spread less and can be treated easily. But cancer starting with radiation scars spreads quickly.

Symptoms of Squamous Cell Carcinoma

  • A mound with a central crater is called a keratoacanthoma. This is the most rapidly growing form of this disease. This is the pre-cancerous stage, which can quickly turn into cancer.
  • A well-defined, red thickened patch on sun-exposed skin, which is scaling may be a sign of this disease.
  • Ulcerating or bleeding patches or sores.
  • Squamous Cell Carcinoma usually looks like large masses of abnormal growth on the skin.
  • Actinic cheilitis, which occurs on the lower lip can be a sign of this disease. It is red, scaling and has blurring border between the lip and the surrounding skin.
  • Superficial Cancer or Squamous cell carcinoma in situ. It is known as Bowen’s disease and has scaly patches on sun-exposed parts of the trunk and extremities.
  • Genital warts looking like Bowen’s disease may also turn into squamous cell carcinoma.

Risk Factors for Squamous Cell Carcinoma

There are few risk factors, which can trigger Squamous Cell Carcinoma in a person. Sun exposure could lead to many growths on skin, which are pre-cancerous in nature and could turn into cancer with time. They are called actinic or solar keratosis. These lesions take a very long time to appear on parts of the body after sun damage. Most affected parts are forehead, cheeks and the backs of the hands. It may take many years to develop into cancer from skin damage, so early protection is the best way to prevent this disease. Risk factors for developing Squamous Cell Carcinoma are listed below.

  • Over exposure to sun could increase risk of developing this disease.
  • People, who are exposed to arsenic or hydrocarbons, are also at higher risk of developing this disease.
  • People, who have been exposed to radiation from different imaging techniques such as X-ray, also have an increased risk of developing this disease.
  • Long term exposure to high level or amount of heat also elevates risk of this disease.
  • Weak immune system due to suppression by infection or drugs also is a risk factor for developing this disease.
  • HPV infections also increase risk of developing squamous cell carcinoma in the anogenital region.

Diagnosis of Squamous Cell Carcinoma

Like other skin cancers Squamous Cell Carcinoma is also diagnosed by a biopsy of the affected area. A small part of skin is scrapped from the area affected by this disease and is studied under microscope to determine presence of cancerous cells and its spread. Skin is usually removed by a circular punch blade, thus this method is also known as punch biopsy.

Prevention and Treatment Of Squamous Cell Carcinoma