Checkpoint Inhibitor Pneumonitis With Pneumomediastinum Following Nivolumab-AVD in Classic Hodgkin Lymphoma: A Case Report

BACKGROUND: Immune checkpoint inhibitors have transformed cancer treatment but may cause pulmonary immune-related toxicities even after therapy completion. OBSERVATIONS: A young patient with classic Hodgkin lymphoma developed checkpoint inhibitor pneumonitis with pneumomediastinum following nivolumab-AVD. She presented with progressive dyspnea, and imaging revealed right lower lobe consolidation with mediastinal air extending into the neck. Symptoms improved rapidly with intravenous corticosteroids, followed by a taper. CONCLUSION: This case describes a rare presentation of pulmonary toxicity in a younger patient and reflects the need for vigilance as immunotherapy use expands across age groups and malignancies.