This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pancreas, Subject name: Pathology
[{'content': 'A 65-year-old woman presents with a 5-week history of yellow skin and sclera, anorexia, and epigastric pain. Her past medical history is significant for insulin-dependent diabetes mellitus. She smoked one pack of cigarettes a day for the past 20 years. Physical examination reveals jaundice and a palpable gallbladder. Laboratory studies show a serum bilirubin level of 10 mg/dL, mostly in the conjugated form, and an elevated alkaline phosphatase (260 U/L). A CT scan of the abdomen discloses a mass in the head of the pancreas and multiple nodules in the liver measuring up to 3 cm. Which of the following is the most likely cause of jaundice in this patient? \nSelect and explain. \nA. Cholelithiasis, B. Cirrhosis, C. Extrahepatic biliary obstruction, D. Hemolysis', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Pancreatic adenocarcinomas often cause obstruction of the common bile duct due to the proximity of the duct to the head of the pancreas. Painless jaundice is a frequent initial symptom of pancreatic cancer. Dilation of the gallbladder in this setting is termed Courvoisier sign. Cirrhosis (choice B) is a late complication of extrahepatic biliary obstruction.Diagnosis: Pancreatic adenocarcinoma', 'role': 'assistant'}]