title: Prediction of poorly differentiated hepatocellular carcinoma using contrast computed tomography.
abstract: BACKGROUND
  Percutaneous radiofrequency ablation (RFA) is a well-established local treatment for small hepatocellular carcinoma (HCC). However, poor differentiation is a risk factor for tumor seeding or intrahepatic dissemination after RFA for HCC. The present study aimed to develop a method for predicting poorly differentiated HCC using contrast computed tomography (CT) for safe and effective RFA.
  
  
  METHODS
  Of HCCs diagnosed histologically, 223 patients with 226 HCCs showing tumor enhancement on contrast CT were analyzed. The tumor enhancement pattern was classified into two categories, with and without non-enhanced areas, and tumor stain that disappeared during the venous or equilibrium phase with the tumor becoming hypodense was categorized as positive for washout.
  
  
  RESULTS
  The 226 HCCs were evaluated as well differentiated (w-) in 56, moderately differentiated (m-) in 137, and poorly differentiated (p-) in 33. The proportions of small HCCs (3 cm or less) in w-HCCs, m-HCCs, and p-HCCs were 86% (48/56), 59% (81/137), and 48% (16/33), respectively. The percentage with heterogeneous enhancement in all HCCs was 13% in w-HCCs, 29% in m-HCCs, and 85% in p-HCCs. The percentage with tumor stain washout in the venous phase was 29% in w-HCCs, 63% in m-HCCs, and 94% in p-HCCs. The percentage with heterogeneous enhancement in small HCCs was 10% in w-HCCs, 10% in m-HCCs, and 75% in p-HCCs. The percentage with tumor stain washout in the venous phase in small HCCs was 23% in w-HCCs, 58% in m-HCCs, and 100% in p-HCCs. Significant correlations were seen for each factor (p < 0.001 each). Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for prediction of poor differentiation in small HCCs by tumor enhancement with non-enhanced areas were 75%, 90%, 48%, 97%, and 88%, respectively; for tumor stain washout in the venous phase, these were 100%, 55%, 22%, 100%, and 60%, respectively.
  
  
  CONCLUSIONS
  Tumor enhancement patterns were associated with poor histological differentiation even in small HCCs. Tumor enhancement with non-enhanced areas was valuable for predicting poorly differentiated HCC.
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Nakachi
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Tamai
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Mori
authors.forename: Naoki
authors.initials: N
authors.lastname: Shingaki
authors.forename: Kosaku
authors.initials: K
authors.lastname: Moribata
authors.forename: Hisanobu
authors.initials: H
authors.lastname: Deguchi
authors.forename: Kazuki
authors.initials: K
authors.lastname: Ueda
authors.forename: Izumi
authors.initials: I
authors.lastname: Inoue
authors.forename: Takao
authors.initials: T
authors.lastname: Maekita
authors.forename: Mikitaka
authors.initials: M
authors.lastname: Iguchi
authors.forename: Jun
authors.initials: J
authors.lastname: Kato
authors.forename: Masao
authors.initials: M
authors.lastname: Ichinose
mesh_terms: D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D003287:Contrast Media; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011856:Radiographic Image Enhancement; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media