Nokea
What is the most likely cause of her pancreatitis?
Correct Answer: B
Rationale: A 2-year-old with acute abdominal pain and pancreatitis, with ultrasound showing a significantly dilated common bile duct tapering distally and dilated intrahepatic ducts, suggests a structural anomaly. Choledochal cyst (Choice B) is a congenital dilatation of the bile ducts, often presenting in young children with pancreatitis, jaundice, or abdominal pain due to bile stasis or obstruction. Bile duct adenoma (Choice A) is a benign tumor, rare in children, and typically asymptomatic unless obstructive, which doesn’t align with the ultrasound findings. Neonatal sclerosing cholangitis (Choice C) is a rare progressive disease usually presenting in infancy with cholestasis, not typically acute pancreatitis or this ultrasound pattern. Sphincter of Oddi dysfunction (Choice D) causes biliary or pancreatic obstruction in adults but is uncommon in children and lacks the structural ductal dilatation seen here. Thus, Choledochal cyst is the most likely cause.