Squamous Cell Carcinoma
Squamous cell carcinoma (SCC) is the second most common type of skin cancer. SCC results from the uncontrolled growth of cells from the outermost layer of the skin, the epidermis. In the United States, there are 250,000 new cases of SCC diagnosed every year. SCC results most of the time from excessive long-term sun exposure. Bowen’s disease is a superficial type of SCC, often referred to as SCC in situ. In situ means that the cancer cells are contained in the outermost layer of the skin where they originated.
SCC and Bowen’s disease do not evolve into malignant melanoma. Malignant melanoma is a different, more aggressive type of skin cancer. Individuals who have had multiple SCCs or other skin cancers related to sun exposure are at an increased risk for malignant melanoma. However, if you have been diagnosed with SCC, you have a 50% chance of getting another one within the next 5 years. Therefore, it is important to follow up with your dermatologist every 6 months, or more often if appropriate, as well as perform a skin self-exam weekly and use sun protection daily.
SCC and Bowen’s disease are locally destructive types of skin cancers. If left untreated, SCC can grow and destroy much of the skin and structures surrounding the skin cancer, possibly resulting in the loss of a nose or an ear. Rarely, certain aggressive types of SCC, especially those of the lips, ears, and scalp and those left untreated, can spread to the lymph nodes, along the nerves, or to other organs, resulting in approximately 2,500 deaths each year.
Anyone can get SCC, but there are certain risk factors that make some individuals more susceptible to SCC than others. Risk factors increase your susceptibility to SCC, but they do not mean you will develop SCC.
Risk factors for SCC include
- Personal and family (genetic) history
- Fair skin with red hair and blue eyes
- Male over 50 years old
- Personal history of SCC, actinic keratosis, or basal cell carcinoma
- Personal history of a rare genetic syndrome, such as albinism or xeroderma pigmentosum
- Chronic skin conditions, such as scarring from burns, chronic skin inflammation, and ulcers
- Environmental exposure
- Excessive long-term sun and ultraviolet light exposure
- Fair skin and having grown up in a southern region
- Frequent exposure to outside work or recreation
- History of multiple sunburns
- Use of an indoor tanning lamp or bed
- Cigarette smoking
- Having a wart virus
- History of radiation therapy
- Medical condition that suppresses the immune system, such as AIDS or medications that organ transplant recipients take to suppress their immune system
- Arsenic and tar exposure
- Excessive long-term sun and ultraviolet light exposure
What does SCC look like?
SCC generally appears as a crusted or scaly growth of the skin that is often red and inflamed. SCC can appear as a growing tumor, a nonhealing growth, or a thick crust. SCC is more common on sun-exposed areas, such as the face, neck, arms, legs, bald scalp, tops of the hands, and ears. However, SCC can appear anywhere on the body, even on the lips, inside the mouth, and on the genitalia. SCC is often tender or painful to the touch and can appear and grow quickly in 2 to 3 months [Figure 1].
Bowen’s disease appears as a red and inflamed flat growth and is found most commonly on the legs, arms, and trunk [Figure 2].
How is SCC diagnosed?
Inspection of your skin by your dermatologist can confirm whether or not a growth is suspicious for SCC. If your dermatologist determines that a growth is suspicious for SCC then a biopsy will be performed. This is a simple procedure performed in the office under local anesthesia. Your growth will then be sent to a pathology lab where thin sections from the growth will be examined under a microscope by a dermatopathologist (a dermatologist or a pathologist trained in the microscopic examination of skin lesions). In the event your biopsy confirms SCC, your dermatologist will discuss treatment options.
Inspection of your skin at home with a weekly skin self-exam can help you identify a growth and help your dermatologist diagnose SCC early. [Table 1] When inspecting your skin for any moles, growths, or spots, look for these signs.
New Changing Different and/or unusual
When inspecting your skin for any moles, growths, or spots, look for these signs.
A common symptom for SCC is tenderness or pain to the touch. Be suspicious of any new growth, changing growth, or growth that looks different or unusual from those in the surrounding area. If any growth is suspicious, you should immediately report it to your dermatologist. Do not try to self-diagnose your condition.
There are many factors that can influence the choice of treatment:
- Type of SCC
- Location, size, number, and aggressiveness of SCC
- Patient’s general health
- Side effects, possible complications, benefits, and cure rate of a procedure
- Dermatologist’s experience and familiarity with a particular procedure
Each case is different. Your dermatologist will decide the most appropriate treatment plan for you.
Commonly used procedures to treat AK include:
- Electrodessication and curettage (ED&C)
- Surgical excision
- Mohs micrographic surgery
- Radiation therapy
For more information refer to “Common Procedures Performed in Dermatology”.
Patients diagnosed with SCC should be examined by their dermatologist at least twice a year. Remember, 50% of individuals with a history of SCC will develop another one within 5 years of diagnosis. Your dermatologist will inspect your skin for any new SCCs and will ensure that any previously treated SCCs are not growing back.
Patients with a previous history of SCC should also perform a weekly skin self-exam. Learning what SCC looks like may help you identify a suspicious growth earlier. Inspecting the location of a previously treated SCC may also help you identify an early recurrence of SCC.
If you cannot see some part of your body, ask your partner or a family member to assist you with your weekly skin self-exam.