Case Report and Review of 7 Similar Cases in the Literature: Cutaneous Sarcoidosis as Side Effect of Pembrolizumab Plus Chemotherapy in Stage IV Squamous Cell Carcinoma of Lung.

Advanced squamous cell lung cancer used to have universally dismal long-term outcomes before the use of immune checkpoint inhibitors (ICIs). Due to the expanding role of ICIs, there has been an increasing number of long-term survivors in this relatively large group of patients. ICIs such as anti-cytotoxic T-lymphocyte-associated protein 4 and anti-programmed cell death protein 1/programmed death-ligand 1 monoclonal antibodies increase the T-cell activation and limit the tumor capacity to escape the adaptive immune response. However, efficacy comes along with unique immune-related adverse events. We present an unusual case of cutaneous sarcoidosis in a 63-year-old white female who was diagnosed with stage IV squamous cell lung cancer developed skin manifestations 3 months after started chemo/pembrolizumab. Sarcoidosis was confirmed by skin punch biopsy and resolved after a short course of systemic glucocorticoid while maintained on pembrolizumab with lower frequency. These sarcoid-like lesions associated with the blockage of programmed death receptor-1 have been increasingly described in many different malignancies especially in melanoma. There is a need for further investigation to the characterization of the population prone to this immune-related adverse events.