title: Multiphase Multi-Detector Row Computed Tomography Imaging Characteristics of Large (>5 cm) Focal Hepatocellular Carcinoma.
abstract: OBJECTIVE
  The aim of this study was to describe the multiphase multi-detector row computed tomography (MDCT) imaging findings of large (>5 cm) focal hepatocellular carcinoma (HCC).
  
  
  METHODS
  Following review of the medical records of 321 patients with newly diagnosed HCC who underwent MDCT within the radiology database from January 2007 to November 2014, 27 patients (20 men and 7 women; mean age, 69 [SD, 10.1] years [range, 49-87 years]) with histologically confirmed HCC greater than 5 cm were included in this institutional review board-approved study. Multiphase, dedicated liver MDCT images of these cases were retrospectively reviewed by 2 radiologists in consensus to describe the enhancement characteristics of these lesions.
  
  
  RESULTS
  Mean tumor diameter was 8.4 (SD, 2.4) cm (range, 5.2-13.5 cm). Cirrhosis was present in 16 (59%) of 27 patients. Seventeen (85%) of 20 patients with available laboratory data presented with elevated alpha-fetoprotein (median, 97 ng/mL). Twenty-three (85%) of 27 demonstrated either heterogeneous enhancement with gradual fill-in (14/27 [52%]) or peripheral enhancement with centripetal fill-in (9/27 [33%]). Twenty-two (81%) of 27 lacked washout on delayed phase images, and 21 (78%) of 27 demonstrated a pseudocapsule. Twenty-seven of 27 lesions were well defined, 8 (30%) of 27 were exophytic, 15 (56%) of 27 were unifocal, 5 (25%) of 20 cases demonstrated vascular invasion, and 7 (26%) of 27 cases presented with extrahepatic metastases.
  
  
  CONCLUSIONS
  Large (>5 cm) focal HCC may present as a dominant mass with a pseudocapsule and initial heterogeneous or peripheral enhancement with gradual or centripetal fill-in without washout on multiphase MDCT. Awareness of this variant is important to allow distinction from other benign (eg, hemangioma) and malignant (eg, cholangiocarcinoma) focal liver lesions.
authors.affiliation: From the *Department of Radiology, †Section of Gastroenterology and Nutrition, ‡Department of Pathology, and §Department of Radiology, The University of Chicago Medicine, Chicago, IL.
authors.forename: Eric M
authors.initials: EM
authors.lastname: Blaschke
authors.forename: Vijaya L
authors.initials: VL
authors.lastname: Rao
authors.forename: Lingyun
authors.initials: L
authors.lastname: Xiong
authors.forename: Helen S
authors.initials: HS
authors.lastname: Te
authors.forename: John
authors.initials: J
authors.lastname: Hart
authors.forename: K Gautham
authors.initials: KG
authors.lastname: Reddy
authors.forename: Aytekin
authors.initials: A
authors.lastname: Oto
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D015588:Observer Variation; D011856:Radiographic Image Enhancement / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity