Pembrolizumab-induced vitiligo in a patient with lung adenocarcinoma: A case report.

Pembrolizumab is an immune checkpoint inhibitor designed to block the interaction between programmed cell death-1 and programmed cell death-ligands 1 and 2. It shows efficacy in the treatment of patients with advanced nonsmall-cell lung cancer, among others. Side effects may involve immune-related adverse events, including vitiligo. We hereby present a 63-year-old Caucasian female with metastatic nonsmall-cell lung cancer. Immunohistochemical analysis showed programmed death-ligand 1 expression on 100% of tumour cells. The patient was eligible for immunotherapy and received pembrolizumab every 3 weeks as the first-line treatment. Three months after initiation of immunotherapy with pembrolizumab, depigmentation appeared on her upper right thoracic area of the skin overlying the affected lung lobe. Immunotherapy was generally well tolerated. Excellent response in our subject with complete remission during 16 months of follow-up potentially indicates that cutaneous immune-related adverse events, such as vitiligo, might be associated with increased efficacy of pembrolizumab in metastatic lung adenocarcinoma.