title: Two-color immunostaining of liver fine needle aspiration biopsies with CD34 and carcinoembryonic antigen. Potential utilization in the diagnosis of primary hepatocellular carcinoma vs. metastatic tumor.
abstract: OBJECTIVE
  To examine immunohistochemical staining of cell block material with antibodies against vascular marker CD34 and polyclonal carcinoembryonic antigen (pCEA) for their clinical utility as part of a 2-color staining protocol in fine needle aspiration (FNA) biopsy of liver masses to distinguish metastases from primary hepatocellular carcinoma (HCC).
  
  
  METHODS
  The authors obtained cell block material from 96 liver FNAs and performed simultaneous (i.e., "dual-color") immunohistochemical staining utilizing antibodies against vascular marker CD34 and pCEA. Cases were blinded and evaluated by the authors for staining pattern and intensity. A consensus was obtained, the results were unblinded, and the diagnoses were correlated.
  
  
  RESULTS
  After staining, 89 cases had sufficient tissue for evaluation. Of the 19 HCC cases, 16 (84%) showed peripheral staining with CD34, and 13 (68%) showed a canalicular or mixed canalicular-cytoplasmic staining pattern for pCEA. Thirteen cases (68%) showed staining for both antigens. All HCC exhibited immunostaining for at least 1 antibody in an appropriate staining pattern. Of the 67 cases of metastatic malignancy, 5 (7%) showed a predominantly transgressing pattern of CD34 staining, 43 (64%) showed a predominantly cytoplasmic or mixed cytoplasmic-canalicular pattern of pCEA staining, and 2 cases (3%) showed staining for both antigens in a transgressing CD34 pattern and cytoplasmic pCEA pattern. None of the 3 normal liver tissue blocks showed staining with either antigen.
  
  
  CONCLUSIONS
  Two-color immunohistochemical staining of liver cell block material obtained by FNA with antibodies to CD34 and pCEA can be helpful in differentiating metastatic tumors vs. primary HCC.
authors.affiliation: Department of Pathology, Presbyterian Medical Center, University of Pennsylvania Health System, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Yoder
authors.forename: Robert L
authors.initials: RL
authors.lastname: Zimmerman
authors.forename: Marluce
authors.initials: M
authors.lastname: Bibbo
mesh_terms: D018952:Antigens, CD34 / Q000378:metabolism*; D001707:Biopsy, Needle; D002272:Carcinoembryonic Antigen / Q000378:metabolism*; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis / Q000473:pathology*; D003937:Diagnosis, Differential; D006801:Humans; D007150:Immunohistochemistry; D008113:Liver Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000556:secondary; D009362:Neoplasm Metastasis / Q000175:diagnosis / Q000473:pathology*
chemical_list: D018952:Antigens, CD34; D002272:Carcinoembryonic Antigen