title: Canalicular immunostaining of aminopeptidase N (CD13) as a diagnostic marker for hepatocellular carcinoma.
abstract: BACKGROUND
  Aminopeptidase N (CD13) is expressed in normal and neoplastic liver tissue, where it exhibits a characteristic canalicular pattern (CD13(can)), similar to that seen for CD10 and when antibodies crossreact with biliary glycoprotein I (p-CEA).
  
  
  OBJECTIVE
  To compare the putative diagnostic use of CD13(can) in differentiating between hepatocellular (HCC) and non-hepatocellular carcinomas metastatic to the liver (non-HCC).
  
  
  METHODS
  A retrospective study comparing 53 HCC specimens with 32 non-HCC specimens. Immunostaining was performed with HepPar1 and antibodies directed against CD10, CD13, p-CEA, and alpha fetoprotein (AFP).
  
  
  RESULTS
  In the HCC group, a canalicular staining pattern was found for CD13, p-CEA, and CD10 in 51, 43, and 33 specimens, respectively. HepPar1 was positive in 29 and AFP in 17 HCC specimens. In the non-HCC group, canalicular immunostaining for CD10 and p-CEA was confined to non-neoplastic liver tissue. One poorly differentiated cholangiocarcinoma showed apical expression of CD13, resembling to some extent CD13(can). Sensitivity and specificity were 96.2% and 97.0%, respectively, for CD13(can), 81.1% and 100% for p-CEA(can), 62.3% and 100%, for CD10(can), 54.7% and 99.9% for HepPar1, and 32.1% and 100% for AFP.
  
  
  CONCLUSIONS
  These results show that CD13(can) is more sensitive in differentiating between HCC and non-HCC than CD10(can), p-CEA(can), HepPar1, and AFP.
authors.affiliation: Department of Pathology, Otto-von-Guericke-University, Leipziger Str. 44, D-39120 Magdeburg, Germany. christoph.roecken@medizin.uni-magdeburg.de
authors.forename: C
authors.initials: C
authors.lastname: Röcken
authors.forename: J
authors.initials: J
authors.lastname: Licht
authors.forename: A
authors.initials: A
authors.lastname: Roessner
authors.forename: S
authors.initials: S
authors.lastname: Carl-McGrath
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015703:Antigens, CD; D001648:Bile Canaliculi / Q000378:metabolism*; D001650:Bile Duct Neoplasms / Q000175:diagnosis; D001653:Bile Ducts, Intrahepatic; D014408:Biomarkers, Tumor / Q000032:analysis*; D018826:CD13 Antigens / Q000032:analysis*; D002272:Carcinoembryonic Antigen / Q000032:analysis; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis*; D015815:Cell Adhesion Molecules; D018281:Cholangiocarcinoma / Q000175:diagnosis; D003937:Diagnosis, Differential; D005260:Female; D006023:Glycoproteins / Q000032:analysis; D006801:Humans; D007124:Immunoenzyme Techniques; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000556:secondary; D008297:Male; D008875:Middle Aged; D015260:Neprilysin / Q000378:metabolism; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D000509:alpha-Fetoproteins / Q000378:metabolism
chemical_list: D015703:Antigens, CD; D014408:Biomarkers, Tumor; C069847:CD66 antigens; D002272:Carcinoembryonic Antigen; D015815:Cell Adhesion Molecules; D006023:Glycoproteins; D000509:alpha-Fetoproteins; D018826:CD13 Antigens; D015260:Neprilysin