Lung erosion following adjuvant immunotherapy with pembrolizumab: a case report.

Background: Pembrolizumab as immunotherapy is increasingly used in adjuvant, neoadjuvant, and standalone therapy and has been described as safe. We share an experience of lung erosion post-thoracic surgery with the use of adjuvant pembrolizumab.

Case Presentation: A 65-year-old Chinese gentleman with metastatic renal cell carcinoma underwent lung metastasis resection and presented with delayed onset pneumothorax while on adjuvant pembrolizumab. Failure of conservative management warranted repeat surgical intervention, and intraoperative findings showed erosion of staple lines possibly caused by poor healing associated with pembrolizumab.

Conclusion: Adjuvant pembrolizumab may impair wound healing, including stapler line healing. Presentation of delayed pneumothorax in a post-surgical patient undergoing immunotherapy should warrant early surgical intervention.