Development of halo nevi in a lung cancer patient: A novel immune-related cutaneous event from atezolizumab

Immunotherapy-induced vitiligo is an immune-related adverse event (irAE) observed in metastatic melanoma patients treated with immune checkpoint inhibitors that target the cytotoxic T-lymphocyteassociated protein 4 (CTLA-4) and programmed cell death-1 (PD-1) pathways. To date, the development of leukoderma, poliosis, and halo nevi during immunotherapy has largely been reported in metastatic melanoma patients. We report a case of immunotherapy-induced leukoderma presenting as halo nevi in a patient with non-small cell lung cancer (NSCLC) treated with atezolizumab, a programmed cell death ligand (PD-L1) antibody. Immunotherapy-induced vitiligo in metastatic melanoma patients may be associated with improved survival, but it remains to be determined whether its occurrence in nonmelanoma cancers has the same prognostic significance.