Squamous Cell Carcinoma

Squamous cell carcinoma (SCC), the second most common type of skin cancer, most often occurs on the sun-exposed skin of elderly men and women. Marjolin ulcers are SCCs that result from exposure to radiation and can arise in areas of chronic injury, typically on the extremities. SCC may also be associated with chronic courses of unmitigated inflammatory disease, such as lichen sclerosis and oral and genital lichen planus.

The annual incidence of SCC is about 100 cases per 100,000 population. Metastasis occurs in 2% to 6% of cases, and 2000 to 3000 adults die of SCC annually.^1,2 An SCC on the lip or ear is more likely to metastasize than an SCC at other sites, so ulcers or lumps in these areas should be taken particularly seriously and biopsies performed readily.

SCC manifests as scaly papules, plaques, erosions, ulcerations, or nodules (A). It frequently resembles Bowen disease but tends to be more exuberant. Low-grade forms of SCC, called verrucous carcinomas, have a warty appearance (B). Histologically, SCC is marked by atypical keratinocytes in the epidermis and dermis.

The preferred treatment is electrodesiccation and curettage, followed by the application of imiquimod 5% cream every other day. Other options include cryotherapy, photodynamic therapy, x-ray or grenz-ray radiation therapy, carbon dioxide laser ablation, simple excision with conventional margins, and Mohs micrographic surgery. Mohs surgery is the modality of choice, especially for areas where tissue-sparing surgery is desirable, such as the face.