Squamous Cell Carcinoma is the second most common type of skin cancer that is caused by ultraviolet rays (sunshine), arsenic ingestion, some wart viruses (human papilloma virus), and radiation. Although rare, this tumor does have the potential to metastasize (spread to the lymph nodes and internal organs) and can be fatal. Tumors that occur within a burn scar and those that are on the lip or ear are more likely to metastasize than those elsewhere.

Early tumors are called squamous cell carcinoma in-situ (or intraepithelial squamous cell carcinoma or Bowen's disease), and tumor cells are only present in the epidermis, the top layer of skin. This early variant isnot life-threatening unless untreated, in which case it can become invasive.

Several treatments exist for squamous cell carcinoma and include:

1. Excision. With this procedure, the tumor is cut out and often stitched together. The skin is sent to a laboratory and examined to ensure that the entire tumor has been removed. The stitches may dissolve or may need to be removed in 7-14 days.
2. ED&C.With this procedure, the tumor is scraped out and the base of the wound is burned using an electric needle or a laser. With this procedure an open sore is left that can take weeks or even months to heal. The final result is often a white depressed scar or pink raised scar that can itch.
3. Mohs' Micrographic Surgery. This procedure has the highest cure rate (lowest risk of the tumor coming back) of any treatment available. With this procedure, the visible tumor is cut out. While the patient waits, the removed skin is processed and slides are made for the surgeon to read and interpret under the microscope. This processing may take 15 to 60 minutes. If the margins are free of tumor, the wound can be left to heal by itself or can be closed using plastic surgery that is most often done right in the office. If all of the tumor is not removed, the surgeon will go back and try to remove the remaining tumor. This second piece of skin (called a stage) is tested and examined under the microscope. This process will go on until all of the tumor is removed.
4. Radiation.This treatment is reserved for those who are late-middle aged or elderly who are not good surgical candidates. Healing can be excellent, although 12 or more treatment sessions are needed.
5. 5-Fluorouracil Cream (Efudex®, Carac®). This chemotherapy cream may be used for squamous cell carcinoma in-situ (Bowen's disease) and results in mild to severe skin irritation. Use for invasive or superficial squamous cell carcinomas is not recommended.
6. Imiquimod (Aldara^®). This cream is not FDA-approved for the treatment of squamous cell carcinoma, although clinical studies have proven that it is effective for squamous cell carcinoma in-situ (Bowen's disease). Skin irritation is common and expected with the use of this cream.