Keywords: AC, adenocarcinoma; EAC, erythema annulare centrifugum; NSCLC, non–small cell lung cancer; PD-1, programmed cell death–1; drug reaction; erythema annulare centrifugum; immune checkpoint inhibitors; immunotherapy; irAEs, immune-related adverse events; lung adenocarcinoma; nivolumab; programmed cell death-1 inhibitors; skin reaction.