Squamous cell carcinoma is a type of skin cancer containing squamous cells.
Squamous cell carcinomas can be found in many parts of the body including the lungs, skin, anus, esophagus, head and neck areas, and cervix.
Squamous cell carcinoma (SCC) is the second most common form of skin cancer. It arises from the cells that make the protective keratin of the epidermis (keratinocytes).
These cancers can be described based on how differentiated the cells are - well-differentiated, moderately differentiated, and poorly differentiated. The less differentiated the lesion, the least amount of normal tissue is preserved and the more aggressive the cancer.
The appearance of squamous cell carcinoma is more varied than basal cell carcinoma. Squamous cell carcinoma also tends to grow more quickly and can, unlike basal cell, spread to other parts of the body, making it more dangerous than basal cell carcinoma.
Those at greatest risk are:
- Those who have fair complexions and poor tanning capacity (burn easily
- Over 55 years of age
- Male (two to three times more common in men than in women)
- Have worked outdoors most of their lives
- Have been exposed to chemical carcinogens (nitrosoureas, polycyclic aromatic hydrocarbons)
- Have been exposed to excessive ionizing radiation (x-rays and gamma rays) or to arsenic
These tumors usually occur in areas of sun-damaged skin and at sites of previous actinic keratoses, burns, scars, or chronic ulcers. SCC usually appears as red, scaling, well-defined plaque and may gradually develop an ulcer, scaly crust or a wart-like surface. Eventually, it can spread into the deeper or surrounding tissues.
Squamous cell cancers are considered superficial when the upper part of the dermis is involved and infiltrative when the lower dermis and fat tissues under the skin (subcutaneous) are invaded.
Diagnosis is often made by medical history and physical examination and confirmed by a skin biopsy (sampling a small portion of tissue for microscopic analysis).
Treatment depends on the size of the tumor, its location, and other factors. In general, the treatment is destruction or removal of the cancer. This can be accomplished by:
Curettage with or without electrodessication. The cancer is burned and removed with a sharp instrument. This is ideal for tumors with distinct borders, for primary lesions and for lesions on surfaces with minimal excess tissue.
Cryosurgery. The cancer is killed by freezing it. This technique uses liquid nitrogen. The nitrogen is applied with an aerosolized spray. This is a low-risk procedure and can be used for people who cannot tolerate surgery.
Surgery. This involves excision that removes the entire lesion with an approximate margin of apparently normal tissue. The area is then closed with sutures.
Moh's micrographic surgery. This involves removing successive horizontal layers of the skin cancer and any surrounding tissue that may be involved. Each layer is microscopically examined and the section that involves tumor is marked. Subsequent horizontal layers remove the areas of tumor involvement, sparing the normal skin tissue.
Radiation treatment. Using x-ray radiation to treat the cancer.
Chemotherapy. This blocks DNA synthesis, thereby preventing normal cell growth and ultimately causing cell death.
Minimizing sun exposure (especially between 10 AM and 3 PM), applying daily sunscreen with SPF 15 or greater, wearing tightly-woven clothing and a hat may help prevent the development of skin cancer.