Risk factors for squamous cell carcinoma of the skin with two illustrative cases and literature review.

Non-melanoma skin cancers, including basal cell carcinoma and squamous cell carcinoma are most frequently observed neoplasms worldwide. Their incidence has steadily been growing. Cutaneous squamous cell carcinoma is more common than basal cell carcinoma in dark complexion individuals. Every year, more than one million new cases of non-melanoma skin cancers (NMSC) are identified in the United States, which is roughly estimated to account for 50% of all cancers in this country. In this article, two illustrative cases are presented, which demonstrate the risk factors for cutaneous squamous cell carcinoma development, emphasizing the relationships and synergistic interactions in the process of carcinogenesis.