Intraductal Papillary Mucinous Neoplasm of the Bile Ducts

ABSTRACT

Intraductal papillary mucinous neoplasms of the bile ducts (IPMNs-B) are uncommon lesions that are characterized by innumerable papillary fronds that contain fine vascular cores, enriched mucin production and bile duct dilatation. IPMNs-B are histologically similar to intraductal papillary mucinous neoplasms of the pancreas and they are occasionally associated with hepatolithiasis. IPMNs-B are considered to be relatively low-grade malignancy and they merit consideration for aggressive surgery. Thus, early and precise diagnosis is important to maximize patient survival. From July 2002 to March 2006, we identified four patients with IPMNs-B at our hospital. In three patients, intrahepatic or extrahepatic bile duct stones were associated with their condition. Computed tomography and magnetic resonance cholangiography were done in all four cases and this demonstrated marked dilatation of the biliary tree. Endoscopic retrograde cholangiography was done in two cases and a large amount of mucin that was draining from the patulous orifice of the duodenal papilla was seen on endoscopy. However, two cases were initially misdiagnosed as intrahepatic cholangiocarcinoma or choledochal cyst with intrahepatic bile duct stones. All the cases underwent ipsilateral hemihepatectomy with caudate lobectomy. Histologically, one case showed to be adenoma, one case was borderline and two cases were invasive adenocarcinoma.