%0 Journal Article
%T Intraductal Papillary Neoplasms of the Bile Duct
%A Masayuki Ohtsuka
%A Hiroaki Shimizu
%A Atsushi Kato
%A Hideyuki Yoshitomi
%A Katsunori Furukawa
%A Toshio Tsuyuguchi
%A Yuji Sakai
%A Osamu Yokosuka
%A Masaru Miyazaki
%J International Journal of Hepatology
%D 2014
%I Hindawi Publishing Corporation
%R 10.1155/2014/459091
%X Intraductal papillary neoplasm of the bile duct (IPNB) is a rare variant of bile duct tumors characterized by papillary growth within the bile duct lumen and is regarded as a biliary counterpart of intraductal papillary mucinous neoplasm of the pancreas. IPNBs display a spectrum of premalignant lesion towards invasive cholangiocarcinoma. The most common radiologic findings for IPNB are bile duct dilatation and intraductal masses. The major treatment of IPNB is surgical resection. Ultrasonography, computed tomography, magnetic resonance image, and cholangiography are usually performed to assess tumor location and extension. Cholangioscopy can confirm the histology and assess the extent of the tumor including superficial spreading along the biliary epithelium. However, pathologic diagnosis by preoperative biopsy cannot always reflect the maximum degree of atypia, because IPNBs are often composed of varying degrees of cytoarchitectural atypia. IPNBs are microscopically classified into four epithelial subtypes, such as pancreatobiliary, intestinal, gastric, and oncocytic types. Most cases of IPNB are IPN with high-grade intraepithelial neoplasia or with an associated invasive carcinoma. The histologic types of invasive lesions are either tubular adenocarcinoma or mucinous carcinoma. Although several authors have investigated molecular genetic changes during the development and progression of IPNB, these are still poorly characterized and controversial. 1. Introduction Intraductal papillary neoplasm of the bile duct (IPNB) is a rare variant of bile duct tumors, which is characterized by papillary or villous growth within the bile duct lumen. Formerly, attention has been drawn to biliary tumors with macroscopically visible mucin secretion, which show predominantly papillary growth within the dilated bile duct lumen and secrete a large amount of mucin. These tumors were called by various names, such as mucin-producing cholangiocarcinoma [1¨C4], mucin-hypersecreting bile duct tumor [5], and intraductal papillary mucinous tumor of the bile duct [6, 7], and were identified as a biliary counterpart of intraductal papillary mucinous neoplasm (IPMN) of the pancreas. On the other hand, biliary intraductal tumors without macroscopically visible mucin secretion are also known, which have a macroscopically recognizable papillary or granular structure but no clinically visible mucin secretion. Since certain morphological features of these tumors, especially intraductal papillary growth pattern, are also similar to those of IPMN of the pancreas, Zen et al. [8] proposed
%U http://www.hindawi.com/journals/ijh/2014/459091/