title: Hepatocellular carcinoma with bile duct tumor thrombi: correlation of magnetic resonance imaging features to histopathologic manifestations.
abstract: OBJECTIVE
  This study was to analyze the magnetic resonance imaging (MRI) features of hepatocellular carcinoma (HCC) with bile duct tumor thrombi, and explore their correlations to histopathology to improve the accuracy of diagnosis.
  
  
  METHODS
  21 patients with pathologically confirmed HCC with bile duct tumor thrombi was performed with a superconducting 1.5-T MR imager within two weeks before operation. Magnetic resonance cholangiopancreatography (MRCP) was performed on 18 patients. Images were retrospectively assessed for the size, location and MRI manifestations of HCC lesions and associated bile duct tumor thrombi. The differentiation of HCC lesions and the pathologic changes of bile duct tumor thrombi were retrospectively analyzed under microscope.
  
  
  RESULTS
  The average diameter of HCC lesions was 5.8±2.8 cm, and ≤5.0 cm in nine cases. Capsule formation was observed on MRI or pathology in 4 cases of HCC (19%). Of the 21 cases with bile duct tumor thrombi, 20 were clearly presented on MRI as cord-like or columnar masses in the bile duct with proximal cholangiectasis. The tumor thrombi showed slightly hypointense on T1WI and slightly hyperintense on T2WI. On enhanced scan, three cases of tumor thrombi, which were mainly consisted of necrotic tissue, did not show enhancement; 17 cases, which were mainly consisted of cancer cells, showed mild or moderate enhancement. On magnetic resonance cholangiopancreatogram (MRCP), 14 cases of tumor thrombi presented as filling defect in the bile duct, abrupt obstruction of the bile duct, and cholangiectasis above the obstruction; four presented as dilated intra-hepatic bile ducts with missing common bile duct. Of the 21 patients, 16 had biliary hemorrhage; three also had tumor thrombi in the portal vein. Seventeen of the 21 HCC with biliary thrombi were poorly differentiated, unencapsulated and with an invasive growth. Nineteen of 21 bile duct tumor thrombi did not invade the bile duct wall and could be easily extracted.
  
  
  CONCLUSIONS
  MRI plays a valuable role in diagnosing HCC with bile duct tumor thrombi and identifying the extent of the thrombi; the MRI features of HCC with bile duct tumor thrombi are associated with its pathologic changes.
authors.affiliation: Department of Radiology, The Second Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong Province, China. liu.qingyu@163.com
authors.forename: Qingyu
authors.initials: Q
authors.lastname: Liu
authors.forename: Jianyu
authors.initials: J
authors.lastname: Chen
authors.forename: Haigang
authors.initials: H
authors.lastname: Li
authors.forename: Biling
authors.initials: B
authors.lastname: Liang
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.forename: Tao
authors.initials: T
authors.lastname: Hu
mesh_terms: D000328:Adult; D000368:Aged; D001650:Bile Duct Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D049448:Cholangiopancreatography, Magnetic Resonance / Q000379:methods*; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D041781:Jaundice, Obstructive / Q000175:diagnosis* / Q000601:surgery; D008111:Liver Function Tests; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA