Common bile duct cysts in neonates, not always a choledochal cyst: A case report

Obstructive jaundice in neonates results from disruption of bile drainage from the liver, which may be related to several conditions. Differentiating between these conditions and intervening rapidly is critical, as the success of treatment for biliary atresia decreases as the infant ages. A 10-week-old term female born at 39 weeks of gestation was brought to the gastroenterology service to assess persistent jaundice. The jaundice was first noted by the patient's mother and pediatrician at 2 weeks of age and was thought to be physiologic. The stool during this period was reported to be normal in color. Laboratory investigations revealed obstructive jaundice (total bilirubin of 9.6 mg/dL; direct bilirubin of 5.6 mg/dL). Imaging demonstrated a cystic dilation of the common bile duct, concurrent dilation of the right hepatic duct, and no visible gallbladder. Given the ultrasound findings and parental report of normally colored stools, the diagnosis of an obstructed choledochal cyst was favored. However, due to the absence of a gallbladder, we obtained a magnetic cholangiography. The findings were similar, and with a presumed diagnosis of a type IV choledochal cyst the patient was taken to the operating room at the age of 91 days. A cystic dilatation of the common bile duct was found, with no distal duct. The structure identified as the right hepatic duct on imaging was found to be an atretic gallbladder. An intraoperative cholangiogram confirmed the diagnosis of cystic biliary atresia, and a Kasai portoenterostomy with Roux-en-Y reconstruction was performed. Postoperatively the hyperbilirubinemia resolved, but her liver function has gradually deteriorated, and she has been referred for a liver transplant. Biliary atresia can present with symptoms and imaging findings that mimic choledochal cysts. Given that the treatment and prognosis of these conditions vary, persistent neonatal jaundice must be worked up expeditiously, and a high index of suspicion for biliary atresia must be maintained.