Aortic rupture following acute aortitis in a patient with head and neck carcinoma treated with nivolumab: a rare but severe immune-related adverse event

Introduction Immune-related adverse events (irAEs) due to immune checkpoint inhibitors may lead to discontinuation and treatment-related death. Acute aortitis is a rare but severe irAE. Case presentation A 67-year-old man with recurrent lower gingival carcinoma received nivolumab therapy. Twenty-three months later, he experienced chest compression, which resulted in syncope. Following a whole-body computed tomography (CT) scanning, which revealed diffuse thickening of the aorta, and systemic assessments of the causes of aortitis, he was diagnosed with acute aortitis due to irAE. Nivolumab discontinuation and oral steroids improved CT findings. However, 11 months after nivolumab discontinuation, he developed an aortic aneurysmal rupture. Endovascular aortic repair rescued him. A durable anti-cancer response was still observed 4 months after the aortic rupture. Conclusion Although severe irAE, such as acute aortitis, occurred, the patient may still achieve a durable response. A broad examination and prompt treatment of irAE can help improve the patient’s survival.