Anti-TIF1γ antibody-positive dermatomyositis associated with nivolumab administration in a patient with advanced oesophageal squamous cell carcinoma: A case report and literature review.

We report a case of anti-transcriptional intermediary factor 1γ antibody-positive dermatomyositis following nivolumab treatment. The patient was successfully treated with pulse steroid therapy and high-dose intravenous immunoglobulin, followed by oral glucocorticoid treatment. Immune checkpoint inhibitors, such as nivolumab, may induce not only myositis as an immune-related adverse event but also dermatomyositides as a paraneoplastic syndrome by distracting immune tolerance. Differentiating between pathologies is warranted if patients develop myositis after immune checkpoint inhibitor administration.