An Unexpected Encounter at the Hepatic Bifurcation

Abstract

Clinical Presentation: A 45-year-old African-American female presented with melena and acute anemia 1 week after an endoscopic sphincterotomy and biliary stent placement for bile duct obstruction. An upper GI endoscopy revealed fresh blood and clots in the second portion of the duodenum, likely coming from the major papilla. After epinephrine injection, ERCP with selective biliary cannulation and balloon sweeps yielded fragments of stones, clots, and debris. On cholangiogram, a large filling defect was also at the hepatic bifurcation. The patient was discharged several days later in stable condition. The patient returned 3 months later with nausea, vomiting, and abdominal pain consistent with acute pancreatitis, with lipase >14,000, ALP >600, and normal bilirubin. An abdominal contrast-enhanced CT scan and ultrasound showed a 3 x 3-cm mass in the CBD extending into the left and right hepatic ducts with biliary dilation. The patient responded to conservative therapy but extensive investigation was continued to identify the cause of the biliary lesion. ERCP with cholangioscopy as well as EUS with FNA revealed the lesion to be a biliary intraductal papillary mucinous neoplasm (B-IPMN). Given her age and the possible malignant potential of B-IPMNs, the patient was referred for local resection, which was performed successfully. Discussion: B-IPMNs have been increasingly recognized over the last 10 years. Due to common embryologic origins, it was postulated that B-IPMN may behave similarily to pancreatic IPMNs. Others theorized that they may follow a more benign course similar to biliary papillomas. Analysis of histopathologic subtypes and type-specific mucin expression patterns of B-IPMN seem to indicate a closer link to the main duct pancreatic IPMN lesions, with associated malignant potential favoring primary resection as the preferred modality of treatment. Several recent studies revealed carcinoma association with B-IPMN lesions ranging between 68-83%, with 5 year survival of 38% after resection. Conclusion: Persistent evaluation of an underlying biliary abnormality first noted during ERCP and on repeat imaging tests to help explain the source of GI bleeding and acute pancreatitis led to the diagnosis of a biliary lesion with malignant potential. Biliary IPMN seem to be a unique clinical entity which warrants further evaluation which may lead to better understanding of biliary malignancies.