title: Differential diagnosis of intrahepatic bile duct dilatation without demonstrable mass on ultrasonography or CT: benign versus malignancy.
abstract: BACKGROUND
  The purpose of the present study was to define the differential diagnostic markers of benign and malignant bile duct strictures without demonstrable mass on ultrasonography (US) or computed tomography (CT) using aspects of clinical, laboratory and imaging findings.
  
  
  METHODS
  Between February 1995 and February 2001, 24 patients who underwent surgical resection for dilations of the bile duct (peripheral and hilar) without visible mass lesion on US or CT were included in our study. Hospital records, laboratory results, findings of imaging studies and pathological findings were reviewed retrospectively.
  
  
  RESULTS
  For laboratory results, levels of alkaline phosphatase (benign 163.9 +/- 145.1 vs malignant 407.25 +/- 481.7; p < 0.05) and CA 19-9 (benign 25.0 +/- 41.1 vs malignant 614.6 +/- 818.5; p < 0.05) levels were significantly elevated in the malignant group compared with that of the benign group. Findings such as thickening of the bile duct wall >/= 5 mm (P < 0.05) on radiological examination, significant regional lymph node enlargement (> 1 cm, p = 0.01) on CT scan and abrupt cut-off (P < 0.01), and separation of bile ducts (P < 0.05) on cholangiogram were differential diagnostic markers between the two groups.
  
  
  CONCLUSIONS
  Preoperative laboratory data such as alkaline phosphatase and CA 19-9, and imaging findings such as significant wall thickening and regional lymph node enlargement on CT, abrupt cut-off and separation of bile duct on cholangiogram are useful differential diagnostic markers for benign and malignant bile duct strictures without demonstrable mass on US or CT.
authors.affiliation: Division of Gastroenterology and Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Hong Joo
authors.initials: HJ
authors.lastname: Kim
authors.forename: Kyu Taek
authors.initials: KT
authors.lastname: Lee
authors.forename: Seung Hoon
authors.initials: SH
authors.lastname: Kim
authors.forename: Jong Kyun
authors.initials: JK
authors.lastname: Lee
authors.forename: Jae Hoon
authors.initials: JH
authors.lastname: Lim
authors.forename: Seung Woon
authors.initials: SW
authors.lastname: Paik
authors.forename: Jong Chul
authors.initials: JC
authors.lastname: Rhee
mesh_terms: D000328:Adult; D000368:Aged; D000469:Alkaline Phosphatase; D001650:Bile Duct Neoplasms / Q000150:complications / Q000175:diagnosis* / Q000601:surgery; D001653:Bile Ducts, Intrahepatic / Q000000981:diagnostic imaging* / Q000473:pathology; D001662:Biliary Tract Surgical Procedures; D018395:CA-19-9 Antigen; D002758:Cholangiography; D002780:Cholestasis, Intrahepatic / Q000175:diagnosis* / Q000209:etiology / Q000601:surgery; D003937:Diagnosis, Differential; D004108:Dilatation, Pathologic / Q000000981:diagnostic imaging / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D014463:Ultrasonography
chemical_list: D018395:CA-19-9 Antigen; D000469:Alkaline Phosphatase