Snapshot A 72-year-old woman presents to the emergency department with generalized fatigue, malaise, and right upper quadrant pain. She has a past medical history of obesity and cholelithiasis. Physical examination is notable for scleral icterus. Abdominal ultrasound demonstrates ductal dilatation without clear cause. Cross-sectional MRI demonstrates a malignancy of the intrahepatic bile duct. Introduction Overview malignancy originating from the epithelial cells of the bile ducts most commonly affecting the extrahepatic bile ducts Epidemiology Demographic slightly more common in men Risk factors chronic inflammation e.g., cholelithiasis and choledocholithiasis liver fluke infections Clonorchis sinensis Opisthorchis viverrini Presentation Symptoms secondary to biliary obstruction pruritus jaundice clay-colored stools dark urine Physical exam right upper quadrant mass (~10% of cases) Imaging Abdominal ultrasound indication initial imaging study when evaluating for causes of biliary obstruction Cross-sectional CT or MRI indication preferred imaging study when evaluating cholangiocarcinoma Differential Gallbladder cancer differentiating factor imaging study demonstrates involvement of the gallbladder Treatment Treatment is geared towards the staging of the malignancy e.g., radiotherapy with chemotherapy Complications Biliary obstruction Pancreatic duct obstruction