Atypical response with bone pseudoprogression in a patient receiving nivolumab for advanced cutaneous squamous cell carcinoma

Currently, there is no established standard of care for patients with metastatic CSCC. Based on the mechanisms of CSCC carcinogenesis has been postulated that these tumors may be amenable to PD-1/PD-L1 blockade. This case illustrates a patient with CSCC with nodal involvement and pulmonary metastases, refractory to two lines of platinum-based regimens and salvage surgery, for whom treatment with nivolumab was recommended. His clinical course was marked by an atypical pattern of response, with initial reduction of soft tissue/visceral lesions, yet development of new bone findings, followed by overall improvement in subsequent scans and sustained disease control upon treatment continuation. The case of patient with metastatic CSCC, refractory, received immunotherapy and evolved with atypical pattern of response.