Severe immune mucositis and esophagitis in metastatic squamous carcinoma of the larynx associated with pembrolizumab.

Background: Pembrolizumab is an anti-programmed death 1 (PD-1) receptor monoclonal antibody that has shown activity as second line treatment for metastatic head and neck squamous cell carcinoma (HNSCC). Immune-related adverse events are now well described complications of PD-1 inhibitors and most organ sites have been shown to be potentially affected.

Case Presentation: We describe a 69-year old patient with a relapsed squamous cell carcinoma of the supraglottic larynx with lung metastasis after receiving adjuvant concurrent cisplatin and radiotherapy.