LAUSR

cSCC: cutaneous squamous cell carcinoma C utaneous squamous cell carcinoma (cSCC) accounts for over 700,000 cases and an estimated 8000 to 10,000 deaths per year in the United States. Although most cSCCs have an excellent prognosis and can be cured with local surgical excision, a subset of cases progress to advanced disease and require additional treatment modalities. Reported rates of metastasis of cSCC range from 2% to 5%, although the presence of risk factors such as perineural invasion or host immunosuppression increases this risk. Metastatic cSCC beyond regional lymph nodes has a poor prognosis and limited therapeutic options. Immune checkpoint blockade with antibodies targeting the programmed cell death protein 1 receptor have emerged as potentially powerful therapies for advanced cSCC. In 2018, the antiprogrammed cell death protein 1 monoclonal antibody cemiplimab was approved in the United States for patients withmetastatic or locally advanced cSCC who are not candidates for curative surgery or radiation. It is possible that immune checkpoint blockade may effectively treat multiple primary cSCCs or premalignant lesions in patients with a high burden of skin cancer, but this has not been adequately studied to date. We report the case of a patient who developed a high-stage primary cSCC during complete response