title: Biphenotypic hepatic tumors: imaging findings and review of literature.
abstract: OBJECTIVE
  To describe imaging findings in biphenotypic hepatic tumors (BPT) and a proposal for new imaging classification based on contrast-enhanced imaging.
  
  
  METHODS
  Retrospective review of CT, MRI, PET/CT, and ultrasound findings in 39 patients with histologically confirmed BPT was performed. Tumor markers including AFP, L3 fraction, CA 19.9, CA 125, and CEA were recorded. Based on the dynamic enhancement features, BPT were categorized into 4 enhancement patterns (Types 1-4). Enhancement patterns were correlated with other imaging findings and tumor markers. Imaging features and tumor markers that were not consistent with diagnosis of hepatocellular carcinoma or intrahepatic cholangiocarcinoma based on enhancement pattern were considered discordant findings.
  
  
  RESULTS
  Enhancement patterns in 29 patients (CT/MR) included 23 Type 2 (continuous peripheral rim of late arterial hyperenhancement with washout or fade in portal venous and/or delayed phases, ±delayed central enhancement) and 2 of each Types 1, 2, and 3. Discordant imaging findings were present in two patients with Type 2 pattern and in one patient with Type 1 pattern. Both AFP and CA 19.9 were elevated in 15 of 33 of patients. Tumor markers AFP and CA 19.9 were discordant in 17 of 21 patients with Type 2 pattern, two of two patients with Type 3 pattern. Most BPTs were markedly PET avid with average SUV max of 8.2. Most frequent ultrasound appearance is peripheral hypoechogenicity and central hyperechogenicity.
  
  
  CONCLUSIONS
  BPT most commonly present with imaging features similar to cholangiocarcinoma or metastases. BPT can be suggested when imaging findings or tumor markers are discordant with the most likely diagnosis based on enhancement pattern.
authors.affiliation: Department of Radiology, College of Medicine, Mayo Clinic, 200 First St. SW, Rochester, MN, 55905, USA.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Wells
authors.affiliation: Department of Radiology, College of Medicine, Mayo Clinic, 200 First St. SW, Rochester, MN, 55905, USA. Venkatesh.Sudhakar@mayo.edu.
authors.forename: Sudhakar K
authors.initials: SK
authors.lastname: Venkatesh
authors.affiliation: Department of Pathology, Mayo Clinic, Rochester, MN, USA.
authors.forename: Vishal S
authors.initials: VS
authors.lastname: Chandan
authors.affiliation: Department of Radiology, College of Medicine, Mayo Clinic, 200 First St. SW, Rochester, MN, 55905, USA.
authors.forename: Jeff L
authors.initials: JL
authors.lastname: Fidler
authors.affiliation: Department of Radiology, College of Medicine, Mayo Clinic, 200 First St. SW, Rochester, MN, 55905, USA.
authors.forename: Joel G
authors.initials: JG
authors.lastname: Fletcher
authors.affiliation: Department of Radiology, College of Medicine, Mayo Clinic, 200 First St. SW, Rochester, MN, 55905, USA.
authors.forename: Geoffrey B
authors.initials: GB
authors.lastname: Johnson
authors.affiliation: Department of Radiology, College of Medicine, Mayo Clinic, 200 First St. SW, Rochester, MN, 55905, USA.
authors.forename: David M
authors.initials: DM
authors.lastname: Hough
authors.affiliation: Department of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN, USA.
authors.forename: Lewis R
authors.initials: LR
authors.lastname: Roberts
mesh_terms: D003287:Contrast Media; D005260:Female; D006801:Humans; D007089:Image Enhancement; D008113:Liver Neoplasms / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D018608:Ultrasonography, Doppler
chemical_list: D003287:Contrast Media
keywords: Biphenotypic hepatic tumor; Computed tomography (CT); Magnetic resonance imaging (MRI); Positron emission tomography (PET); Ultrasound (US)