Allergic bronchopulmonary mycosis induced by pembrolizumab for bladder cancer: A case report.

Pembrolizumab is an immune checkpoint inhibitor (ICI) of programmed cell death-1 category, used for treating various types of cancer. ICIs can sometimes result in immune-related adverse events. Allergic bronchopulmonary mycosis (ABPM) induced by ICI has rarely been reported. We hereby report the case of an 83-year-old woman who experienced non-Aspergillus ABPM with eosinophilia induced by pembrolizumab that had been prescribed for treating bladder cancer. Steroid monotherapy with prednisone was successful and pembrolizumab could be resumed. Through the present case report, we urge the clinicians to be aware of the potential risk of ABPM as a T-helper type 2-associated immune-related adverse event.