Sarcoidosis-like syndrome and lymphadenopathy due to checkpoint inhibitors.

Immunotherapy with checkpoint inhibitors has revolutionized the management of metastatic melanoma. These checkpoints, namely the cytotoxic T lymphocyte antigen 4 and the programmed T cell death 1 receptor, possess an inhibitory effect on the T cell function. Pharmacologic inhibition of cytotoxic T lymphocyte antigen 4 with ipilimumab and programmed T cell death 1 with either pembrolizumab or nivolumab has resulted in long-term sustained responses among patients with metastatic melanoma. The adverse events of these medications are predominantly immune related. Sarcoidosis-like syndrome/lymphadenopathy represents a challenging adverse event to the oncologist as it can be mistaken for progressive disease. Hence, awareness of such adverse event and obtaining a biopsy of the enlarged lymph nodes will confirm the diagnosis and avoid the unnecessary change of current therapies for those with stage IV disease or adding new ones for those with stage III disease. We report three cases of immunotherapy-related sarcoidosis-like syndrome/lymphadenopathy; two cases occurred during adjuvant ipilimumab for stage III surgically resected melanoma and one case during pemprolizumab for stage IV metastatic melanoma.