About Squamous Cell Carcinoma
Squamous Cell Carcinoma (SCC) of the skin is the second most common form of skin cancer, and something our doctors treat regularly at Brisbane City Skin Clinic. It is estimated that there are approximately 200,000 new Squamous Cell Carcinomas diagnosed in Australia each year and over 1000 people die from metastatic Squamous Cell Carcinoma of the skin annually.
It starts from squamous cells in the outermost layer of the skin which start to overgrow. Squamous cells are flat cells located near the surface of the skin that shed continuously as new ones form. Squamous Cell Carcinoma occurs when DNA damage from exposure to ultraviolet radiation (most commonly from the sun) or other damaging agents trigger abnormal changes in the squamous cells.
There are a number of signs to look for when identifying potential Squamous Cell Carcinomas as they can present in a variety of ways. Surface changes may include:
– Thick, red, scaly patches that may bleed or crust;
– Raised growths or lumps, possibly with a depression in the middle;
– Raised areas or new sores on existing scar or ulcer sites;
– Open sores (possibly with oozing or crusting) that do not heal, or heal and then reappear;
– Wart-like growths;
– Flat sores with crusting;
The lesion will generally range between a few millimeters to several centimeters in diameter and might be inflamed or tender.
They most commonly appear on body parts that have received the most frequent sun damage such as on the backs of the hands, forearms, legs, scalp, ears and lips. On the lips a Squamous Cell Carcinoma can present as a persistent small ulcer or thickened firm scaly skin.
An early type of Squamous Cell Carcinoma can commonly present as a slightly raised red, scaly patch that progressively enlarges. This superficial type of Squamous Cell Carcinoma can be called three different names but they all mean the thing, Squamous Cell Carcinoma insitu, intraepithelial carcinoma and Bowens disease. It is still important to treat these lesions otherwise they will continue to grow and they have a 10% chance every year of becoming invasive Squamous Cell Carcinomas.
While the majority of Squamous Cell Carcinomas can be easily and successfully treated, if allowed to grow, they become disfiguring, dangerous and even deadly. Whilst not as commonly as melanoma, untreated Squamous Cell Carcinomas can become deeply invasive, grow into deeper layers of skin and spread to other parts of the body. Squamous Cell Carcinomas with the potential to cause problems are those occurring on the lip, ear and scalp; those over 2cm in diameter; and those showing growth around nerves or with a more aggressive pattern under the microscope.
Treatment of Squamous Cell Carcinoma
Once a Squamous Cell Carcinoma is suspected by your doctor a biopsy (or partial sample) is often initial performed and sent to the pathologist for examination. This is done for two reasons; firstly to ensure that the lesion is an Squamous Cell Carcinoma. This can avoid unnecessary surgery if the lesion is one of the many benign lesions that can mimic Squamous Cell Carcinoma, such as a seborrheic keratosis. Secondly to determine if there are any aggressive characteristics of the Squamous Cell Carcinoma as this may alter the approach to the surgical removal.
The most effective way to treat an invasive Squamous Cell Carcinoma is by surgical excision. This involves removing the whole lesion with a 4mm safety margin and most frequently suturing the skin back together. The lesion is then examined under the microscope by a pathologist to ensure the lesion is completely removed. Very occasionally if the Squamous Cell Carcinoma has some “aggressive” pathological features or has not been completely removed with a safety margin, further surgery, or sometimes radiation therapy is required.
In some situations and in some locations when the Squamous Cell Carcinoma is very small, they can be treated by a scraping called curettage or by freezing with liquid nitrogen.
The early, non-invasive, type of Squamous Cell Carcinoma, intraepithelial carcinoma can also sometimes be treated with a special cream called efudix or treated with cryotherapy.