title: Intraductal papillary neoplasms of the bile duct.
abstract: 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.
authors.affiliation: Department of General Surgery, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuoh-ku, Chiba 260-8670, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Ohtsuka
authors.affiliation: Department of General Surgery, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuoh-ku, Chiba 260-8670, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Shimizu
authors.affiliation: Department of General Surgery, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuoh-ku, Chiba 260-8670, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kato
authors.affiliation: Department of General Surgery, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuoh-ku, Chiba 260-8670, Japan.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Yoshitomi
authors.affiliation: Department of General Surgery, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuoh-ku, Chiba 260-8670, Japan.
authors.forename: Katsunori
authors.initials: K
authors.lastname: Furukawa
authors.affiliation: Department of Medicine and Clinical Oncology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan.
authors.forename: Toshio
authors.initials: T
authors.lastname: Tsuyuguchi
authors.affiliation: Department of Medicine and Clinical Oncology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Sakai
authors.affiliation: Department of Medicine and Clinical Oncology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Yokosuka
authors.affiliation: Department of General Surgery, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuoh-ku, Chiba 260-8670, Japan.
authors.forename: Masaru
authors.identifier: 0000-0001-9851-2888
authors.initials: M
authors.lastname: Miyazaki