title: A pictorial review of benign hepatocellular nodular lesions: comprehensive radiological assessment incorporating the concept of anomalous portal tract syndrome.
abstract: OBJECTIVE
  Although the pathological categorization system advocated by the International Working Party (IWP) on Terminology has been helpful in categorizing benign hepatocellular lesions, the diverse clinicopathological features of the lesions still cause confusion of diagnosis in clinical settings. Recently, an integrated disease concept termed "anomalous portal tract syndrome" (APTS) has been proposed as a congenital anomaly of the portal tract, being a single unifying etiological factor underlying the disorder. In this article, we discuss the radiological features of benign nodular hepatocellular lesions incorporated in the concept of APTS.
  
  
  METHODS
  We systematically reviewed the literature on benign hepatocellular lesions based on the concept of APTS, as well as standard IWP terminology. For this pictorial review, we selected six representative cases and assessed the radiological features of the cases based on the concept of APTS.
  
  
  RESULTS
  The comprehensive assessment based on APTS enabled the systematic categorization of benign hepatocellular lesions, including nodular regenerative hyperplasia, large regenerative nodules, partial nodular transformation, focal nodular hyperplasia, and hepatocellular adenoma, and was helpful in understanding the overlapping features of these lesions.
  
  
  CONCLUSIONS
  Although the disease concept of APTS is still evolving, it is nonetheless helpful in comprehensively understanding the clinicopathological and radiological features of various benign hepatocellular lesions.
authors.affiliation: Department of Radiology, Chiba University Hospital, 1-8-1 Inohana, Chou-ku, Chiba, Chiba, 260-8677, Japan. takueda-rad@umin.ac.jp
authors.forename: Takuya
authors.initials: T
authors.lastname: Ueda
authors.forename: Jay
authors.initials: J
authors.lastname: Starkey
authors.forename: Kensaku
authors.initials: K
authors.lastname: Mori
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Fukunaga
authors.forename: Ryota
authors.initials: R
authors.lastname: Shimofusa
authors.forename: Ken
authors.initials: K
authors.lastname: Motoori
authors.forename: Manabu
authors.initials: M
authors.lastname: Minami
authors.forename: Fukuo
authors.initials: F
authors.lastname: Kondo
mesh_terms: D018248:Adenoma, Liver Cell / Q000098:blood supply / Q000000981:diagnostic imaging; D006528:Carcinoma, Hepatocellular / Q000098:blood supply / Q000000981:diagnostic imaging; D003937:Diagnosis, Differential; D020518:Focal Nodular Hyperplasia / Q000000981:diagnostic imaging*; D006801:Humans; D006965:Hyperplasia / Q000000981:diagnostic imaging; D008102:Liver Circulation; D008107:Liver Diseases / Q000000981:diagnostic imaging; D008113:Liver Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging; D011168:Portal System / Q000000981:diagnostic imaging*; D013577:Syndrome; D014057:Tomography, X-Ray Computed / Q000379:methods*