International Academy of Cosmetic Dermatology
SQUAMOUS CELL CARCINOMA
Squamous cell carcinoma (SCC) is the second most common type of skin cancer in man. It is a malignancy that develops from cells in the upper layer of the epidermis. An estimated 250,000 new cases are diagnosed in the United States, annually. Although SCCs are more common in fair-skinned individuals, more than two thirds of the skin cancers that dark-skinned individuals develop are squamous cell, usually arising on the sites of preexisting inflammatory skin conditions or burn injuries.
Chronic exposure to ultraviolet radiation in sunlight is the most important risk factor, and tumors appear most frequently on sun-exposed areas. The rim of the ear and the lower lip are especially vulnerable. It can develop from a sun-induced precursor lesion, an actinic keratosis, or in apparently normal skin. SCC may arise in longstanding, non-healing sores, old burns, sites of radiation, or chemical exposure (e.g. arsenic). Chronic skin inflammation and immune suppression also increase the risk of developing SCC.
SCC often presents as a warty, scabbed growth that easily bleeds and will not heal. Sometimes, it will appear as a scaly patch similar to eczema, or an ulcer. When it develops within burn injuries, sores, or old scars, it tends to have a cauliflower-like appearance and grows rapidly. A diagnosis of SCC is established with a simple skin biopsy performed under local anesthesia in the office.
While it is locally invasive, SCC usually remain localized. Early diagnosis and appropriate treatment provide the best opportunity for cure. Surgical excision is the most broadly used treatment. It is well tolerated, extremely effective, and the completeness of the procedure can be evaluated through histological assessment of the specimen's margins. For superficial lesions, other destructive methods are available. Most cutaneous SCCs are curable but a small subset of tumors may recur, metastasize to lymph nodes or distant organs, and have a poor prognosis.
Vesna Petronic-Rosic, MD, MSc