Pembrolizumab Induced Aortitis in a Patient With Head and neck Cancer: A Case Report

We present a rare case of aortitis in a 65-year-old male diagnosed with p16-positive, metastatic oropharyngeal squamous cell carcinoma on pembrolizumab therapy. The patient has a history of rheumatoid arthritis. Patient presented to the emergency room with cough, sudden onset pleuritic chest pain, and low-grade fever. Extensive infectious and rheumatological work up for the patient's symptoms yielded no significant findings. Radiologic workup suggested aortic inflammation. Because of the temporal relationship of onset of symptoms with immune checkpoint inhibitor therapy, a diagnosis of immune checkpoint related adverse effect (IrAE) associated vasculitis was established. To our knowledge, this is the first case of this unusual side effect of pembrolizumab presenting in the unique context of underlying autoimmune disease.