Pembrolizumab-induced esophagitis dissecans superficialis in a patient with squamous cell lung carcinoma

Abstract

Pembrolizumab, a treatment for advanced cancers, can cause immune-related adverse events (irAEs), and among these, esophagitis is rare. We report on an 80-year-old man with squamous cell lung carcinoma who started treatment with pembrolizumab at 200 mg every three weeks. After the first administration, the patient developed odynophagia. Esomeprazole did not improve symptoms, and upper gastrointestinal endoscopy and biopsy revealed esophagitis dissecans superficialis, which was considered as an irAE. Oral prednisolone was started, and odynophagia rapidly improved and the mucosal lesions healed. However, steroid withdrawal was unsuccessful because of repeated relapses. When patients on immune checkpoint inhibitors develop dysphagia, esophagitis should be suspected as an irAE.