Pembrolizumab-induced large duct cholangiopathy: Diagnosis and follow-up imaging

Immune-checkpoint inhibitor mediated hepatobiliary injury is an emerging concern in cancer treatment. Most of these adverse reactions are attributed to nivolumab and are characterized by panlobular hepatitis. Large duct cholangiopathy related to these drugs is extremely rare. We present a case of adenocarcinoma of lung treated with pembrolizumab who developed biochemical and imaging features consistent with cholangiopathy characterized by common bile duct dilatation, wall enhancement, and gallbladder wall edema. On follow-up in the fourth month, the imaging features persisted despite the normalization of liver enzymes. To the best of our knowledge, this is the first description of diagnosis and follow-up imaging of pembrolizumab-related cholangiopathy in imaging literature.