Bile duct obstruction in a patient treated with nivolumab as second-line chemotherapy for advanced non-small-cell lung cancer: a case report.

Immune checkpoint inhibitors (ICIs) are becoming a standard therapy for non-small-cell lung cancer in the advanced stage. As these ICIs become widely available in clinical practice, immune-related adverse effects will become more common. Here we report a patient with lung adenocarcinoma who was treated with nivolumab and developed obstruction because of biliary inflammation. A 63-year-old Japanese man having lung adenocarcinoma with pleural dissemination complained of epigastric pain on the fifth cycle of nivolumab. Computed tomography showed wall thickening at the lower part of the bile duct and cholecystitis. Endoscopic retrograde cholangiopancreatography was repeatedly performed for drainage and stenting of the bile duct. Biopsies did not show obvious malignancy. Laboratory data on day 85 demonstrated grade 3 elevation of serum alkaline phosphatase, transaminase, and amylase levels. We initiated high-dose oral prednisone, resulting in gradual improvement of symptoms and laboratory data. Follow-up magnetic resonance cholangiopancreatography demonstrated no progression of duct obstruction, which confirmed the absence of biliary malignancy. Combined with results from previous reports, nivolumab may cause extrahepatic cholangitis.