title: Highly well differentiated hepatocellular carcinoma and benign hepatocellular lesions. Can they be distinguished on fine needle aspiration biopsy?
abstract: OBJECTIVE
  To determine whether highly well differentiated hepatocellular carcinoma can be distinguished from benign hepatocellular lesions on fine needle aspiration biopsy (FNAB).
  
  
  METHODS
  Ninety-five FNABs from 88 patients with hepatic masses/diffuse conditions were reviewed according to new cytologic criteria established by Takenaka et al. They were classified into well-, moderately and poorly differentiated hepatocellular carcinomas (W-, M- and P-HCC) and benign aspirates and histologically verified.
  
  
  RESULTS
  There were 21 W-HCC, 39 M-HCC, 10 P-HCC, 3 problematic and 22 benign aspirates. The most useful criteria for diagnosing highly W-HCC were architectural features on the smears/cell block sections, including hypercellularity; arborescent, cohesive clusters; broad trabeculae; transgressing and peripheral endothelium; and cytologic details of small, monotonous hepatocytes with nuclear crowding, decreased cytoplasm, increased nuclear/cytoplasmic ratio, atypical naked nuclei and tumor giant cells. Well-defined cytoplasmic borders, abundant thick and monotonous cytoplasm, eccentric nuclei, thick nuclear membranes, irregular nuclear contours, increased chromatin density, irregular chromatin distribution and macronucleoli were not always detectable in highly W-HCC. In fact, some of them were seen in dysplastic hepatocytes. Deficient reticulin patterns and diffuse sinusoidal CD34 reactivity were helpful.
  
  
  CONCLUSIONS
  Experience, attention to architectural and cytologic details in smears/cell blocks and clinicopathologic correlation should reduce the number of indeterminate reports. However, there will always remain some cytohistologically challenging cases.
authors.affiliation: Department of Pathology, National University Hospital, National University of Singapore, Singapore, Republic of Singapore. patweea@nus.edu.sg
authors.forename: Aileen
authors.initials: A
authors.lastname: Wee
authors.forename: Barbro
authors.initials: B
authors.lastname: Nilsson
mesh_terms: D000293:Adolescent; D000368:Aged; D000369:Aged, 80 and over; D001707:Biopsy, Needle; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis* / Q000473:pathology; D002454:Cell Differentiation / Q000502:physiology; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D020518:Focal Nodular Hyperplasia / Q000175:diagnosis / Q000473:pathology; D006801:Humans; D008103:Liver Cirrhosis / Q000175:diagnosis / Q000473:pathology; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D014463:Ultrasonography