Squamous Cell Carcinoma: SCC

Skin cancer ---> Non melanoma skin cancer ---> squamous cell carcinoma

SCC is the second most common form of skin cancer and is derived from the epithelial keratinocyte. SCC can deeply invade surrounding structures and metastasizes most commonly to regional lymph nodes. In immunosuppressed transplant individuals, SCC is the most common skin cancer, occurring 65 to 250 times more frequently than in the general population. SCC in these individuals tends to have more aggressive behavior.
Several precursor lesions to invasive SCC exist, most commonly actinic keratosis and Bowen's disease (in situ SCC). Erythroplasia of Queyrat, another precursor lesion, represents SCC in situ on the glans penis. Histologically, SCC shows malignant degeneration of epithelial cells with differentiation toward keratin formation. SCC often appears clinically as a non healing sore with ulceration and inflammatory pink borders or an erythematous papulonodule with overlying keratotic crust or ulceration. These tumors most often arise in chronically actinically damaged skin or within an actinic keratosis, but they may also develop in burn scars or chronic inflammatory wounds. These lesions may infiltrate widely. Metastasis to regional lymph nodes accounts for approximately 80% to 90% of metastatic cases. Distant sites, such as lung, liver, brain, bone, and skin, account for the other 10% to 20%. Metastatic SCC portends a poor prognosis with a 10-year survival rate for regional lymph node disease of less than 20% and for distant disease of 10%.
Accurate assessment of the higher-risk cutaneous SCCs is handicapped because of the lack of large prospective studies using multivariate analysis. Nine variables, however, have been identified as prognostic risk factors by retrospective analysis.

Etiology of BCC and SCC

Surgical Treatment of Nonmelanoma Skin Cancers

Adjuvant and Primary Radiation Therapy for nonmelanoma cancers