title: Intraductal tubulopapillary neoplasm of the bile duct: A case report and review of the published work.
abstract: Recent studies have suggested that a peculiar tumor mimicking intraductal tubulopapillary neoplasms (ITPN) of the pancreas can develop in the bile duct. Here, we present a similar case and review the published work on the newly proposed biliary neoplasm. A 68-year-old woman was referred to us for further evaluation of a liver mass. On imaging, the tumor was 40 mm in size and intraductal in location, and was enhanced slightly on the contrast-enhanced computed tomography. No mucin overproduction was found. She underwent right hepatectomy for suspected intraductal papillary neoplasm of the bile duct. The tumor histologically consisted of the biliary-type epithelium arranged in a tubular architecture within the dilated bile duct. Tumor cells had features of high-grade dysplasia but no stroma invasion. No expressions of MUC2 and MUC5AC were noted. On molecular studies, KRAS and GNAS appeared to be wild-type genotypes. These features were in keeping with ITPN. In the published work review, "biliary ITPN" described in four manuscripts were characterized by predominantly intrahepatic/hilar in location, histological tubular architecture, negative expressions of MUC2 and MUC5AC, and uncommon alterations of KRAS, GNAS and BRAF. Although invasive malignancy was present in 71%, the outcome was favorable with the 5-year survival expected to be approximately 90%. Biliary ITPN are supposedly uncommon, but a greater awareness of this condition may give more chance to diagnose the underrecognized neoplasm.
authors.affiliation: Department of Gastroenterology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakagawa
authors.affiliation: Department of Gastroenterology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Arisaka
authors.affiliation: Department of Hepato-Biliary-Pancreatic Surgery, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Ajiki
authors.affiliation: Department of Diagnostic Pathology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Kohei
authors.initials: K
authors.lastname: Fujikura
authors.affiliation: Department of Gastroenterology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Atsuhiro
authors.initials: A
authors.lastname: Masuda
authors.affiliation: Department of Gastroenterology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Mamoru
authors.initials: M
authors.lastname: Takenaka
authors.affiliation: Department of Gastroenterology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Shiomi
authors.affiliation: Department of Gastroenterology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Okabe
authors.affiliation: Department of Hepato-Biliary-Pancreatic Surgery, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Takumi
authors.initials: T
authors.lastname: Fukumoto
authors.affiliation: Department of Hepato-Biliary-Pancreatic Surgery, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Yonson
authors.initials: Y
authors.lastname: Ku
authors.affiliation: Department of Gastroenterology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Azuma
authors.affiliation: Department of Diagnostic Pathology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Yoh
authors.initials: Y
authors.lastname: Zen
keywords: GNAS; KRAS; cholangiocarcinoma; intraductal papillary neoplasm; intraductal papillary neoplasm of the bile duct; intraductal tubulopapillary neoplasm