When immunity backfires: pembrolizumab-induced bilateral pneumothorax in a patient with metastatic HPV-associated oropharyngeal carcinoma

Pneumothorax is a rare but reported pulmonary immune-related adverse event associated with PD-1/PD-L1 inhibitors; risk may be heightened by subpleural metastases undergoing immune-mediated necrosis/cavitation.New dyspnoea after checkpoint blockade warrants chest imaging for pneumothorax alongside evaluation for immune checkpoint inhibitor pneumonitis.Management should follow evidence-based pneumothorax guidelines and be individualized to performance status and goals of care.