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Clinical Images: Nivolumab‐induced tracheobronchial chondritis in a patient with hypopharyngeal cancer

The patient, a 66-year-old man with multiple lymph node metastases, began receiving immune checkpoint inhibitor (ICI) treatment with nivolumab after undergoing surgical resection for hypopharyngeal cancer. Before ICI, no abnormalities of the trachea and bronchi were noted on bronchoscopy ( A and B ), contrast-enhanced computed tomography (CE-CT) ( C and D ), and ﬂ uorodeoxyglucose – positron emission tomography (FDG-PET)/CT ( E ). ICI treatment shrank the cervical lymph nodes. However, after the 24th course of ICI, the patient had precordial pain and increased sputum with elevated C-reactive protein (7.11 mg/dl). Although respiratory infections were initially sus-pected, antibiotics had no effect, and tests of sputum and blood cultures were negative. Redness and swelling of the tracheal and bronchial mucosa were seen on bronchoscopy ( F and G ), tracheal and bronchial wall thickening on CE-CT ( arrows in H and I ), and high FDG uptake of the trachea and bronchi on FDG-PET/CT ( arrows in J ), indicating tracheobronchial chondritis. Lymphocytic in ﬁ ltrates in soft tis-sue around tracheal cartilage were noted on biopsy. High levels of matrix metalloproteinase 3 (1,240 ng/ml) and type II collagen antibody (25.9 U/ml) were found. Other immune tests, including antinuclear antibody, rheumatoid factor, and antineutrophil cytoplasmic antibodies, yielded negative results. The patient was diagnosed as having nivolumab-induced tracheobronchial chondritis. High-dose steroids and methotrexate were initiated, but relapse was observed during tapering. Intravenous infusion of tocilizumab (TCZ) was added, and the patient ’ s condition improved 3 months after TCZ initiation, showing normalization of the trachea and bronchi on bronchoscopy ( K and L ), reduced wall thickening on non – CE-CT ( M and N )