Squamous cell carcinoma is the second most common form of nonmelanoma skin cancer following basal cell carcinoma. Squamous cell carcinomas are usually slow growing and can be difficult to spot, especially when they appear on skin that has other signs of sun damage, such as changes in pigmentation, loss of elasticity and wrinkling.

Most squamous cell carcinomas result from prolonged exposure to ultraviolet (UV) radiation, either from sunlight or from tanning beds or lamps.

Symptoms

• A firm, red nodule on your face, lower lip, ears, neck, hands or arms
• A flat lesion with a scaly crust on your face, ears, neck, hands or arms
• A new ulceration or raised area on a pre-existing scar or ulcer
• An ulcer or flat, white patch inside your mouth
• A red, raised patch or ulcerated sore in the anus or on your genitals

Risk factors

• Chronic sun exposure
• Fair skin
• Older age
• A personal history of skin cancer
• Smoking
• Weakened immune system
• Skin inflammation or injury

Complications

Tumors on the lips and ears- squamous cell carcinomas in these locations are more likely to spread to other sites or recur after treatment

Large tumors- squamous cell carcinomas measuring about 3/4 inch (about 2 centimeters) or more — are also more likely to spread than smaller tumors

Deep tumors- squamous cell carcinomas that have deeply invaded muscle, cartilage or bone are more likely to recur

Tests and diagnosis

Skin biopsy- A suspected squamous cell carcinoma is often biopsied by shaving off the top layers of skin with a surgical blade

Prevention

• Avoid the midday sun. Sunlight is strongest between 10 a.m. and 4 p.m. sun protection factor (SPF) of at least 15 when you go outside, year-round.

• Apply sunscreen 20 to 30 minutes before sun exposure and reapply it every two hours throughout the day as well as after swimming or exercising
• Vitamin D may help lower the risk of skin cancers
• Be aware of sun-sensitizing medications like ibuprofen, isotretinoin
• Wear protective clothing and sun glasses

Treatment

The type of squamous cell carcinoma treatment usually depends on the size, location and aggressiveness of the tumor

• Cryosurgery using liquid nitrogen for small squamous cell carcinoma
• Simple excision of the cancerous tissue and a surrounding margin of healthy skin
• Lasers are often used to treat superficial carcinomas on the lips
• Radiotherapy or chemotherapy for advanced diseases which are not surgically correctable.