title: Peripheral mass-forming cholangiocarcinoma in cirrhotic liver.
abstract: OBJECTIVE
  The purpose of this study was to determine whether particular enhancement patterns of intrahepatic cholangiocarcinoma in cirrhotic liver suggest the correct diagnosis.
  
  
  METHODS
  The CT findings on 28 lesions in 26 patients with underlying liver cirrhosis and pathologically proven cholangiocarcinoma were retrospectively evaluated. The CT findings of hepatocellular carcinoma (HCC) in a control group of 79 subjects also were analyzed. The relative attenuation and enhancement pattern of the lesions were evaluated by two observers in consensus. The difference between the enhancement pattern of cholangiocarcinoma and that of HCC was statistically analyzed with the Fisher's exact test.
  
  
  RESULTS
  The prevalent enhancement patterns of cholangiocarcinoma on enhanced CT scans differed depending on tumor size. Peripheral rimlike enhancement was the most frequent (nine of 20 cases) pattern in tumors larger than 3 cm in diameter. A washout pattern on portal venous phase scans was the most frequent (five of eight cases) in tumors smaller than 3 cm in diameter. For tumors smaller than 3 cm in diameter, there was no significant difference between the enhancement pattern of cholangiocarcinoma and that of HCC. For tumors larger than 3 cm, the presence of peripheral rimlike enhancement or centripetal enhancement and the absence of a washout pattern were significant findings for differentiating cholangiocarcinoma from HCC (p < 0.0001).
  
  
  CONCLUSIONS
  The contrast enhancement patterns of cholangiocarcinoma in cirrhotic liver on multiphasic helical CT scans were found to differ depending on tumor size. Because of the overlapping imaging findings in the two diseases, for any hypovascular lesion smaller than 3 cm in a cirrhotic liver, the diagnosis of cholangiocarcinoma should be seriously considered along with that of HCC.
authors.affiliation: Department of Radiology and Institute of Radiation Medicine, Seoul National University Hospital, 28, Yongon-dong, Chongno-gu, Seoul 110-744, Korea.
authors.forename: Su Jin
authors.initials: SJ
authors.lastname: Kim
authors.forename: Jeong Min
authors.initials: JM
authors.lastname: Lee
authors.forename: Joon Koo
authors.initials: JK
authors.lastname: Han
authors.forename: Ki Hyun
authors.initials: KH
authors.lastname: Kim
authors.forename: Jae Young
authors.initials: JY
authors.lastname: Lee
authors.forename: Byung Ihn
authors.initials: BI
authors.lastname: Choi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001650:Bile Duct Neoplasms / Q000150:complications / Q000000981:diagnostic imaging*; D001653:Bile Ducts, Intrahepatic / Q000000981:diagnostic imaging*; D006528:Carcinoma, Hepatocellular / Q000150:complications / Q000000981:diagnostic imaging*; D018281:Cholangiocarcinoma / Q000150:complications / Q000000981:diagnostic imaging*; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008103:Liver Cirrhosis / Q000150:complications / Q000000981:diagnostic imaging*; D008113:Liver Neoplasms / Q000150:complications / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011856:Radiographic Image Enhancement / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D003287:Contrast Media