title: Hepatocyte differentiation markers in adenocarcinoma of the prostate: hepatocyte paraffin 1 but not arginase-1 is specifically expressed in a subset of prostatic adenocarcinoma.
abstract: Prostate adenocarcinoma and hepatocellular carcinoma (HCC) are common cancer types. Both may present with bone metastases, and both are known to be CK7/CK20 negative. Thus, diagnosis of less well-differentiated tumors at metastatic sites essentially relies on immunohistochemical confirmation. However, insufficient data exist on the expression status of the main 2 hepatocyte markers hepatocyte paraffin 1 (HepPar-1) and arginase-1 (Arg-1) in prostatic adenocarcinoma. We screened 557 prostate carcinoma cases for expression of these 2 markers using tissue microarrays. Sixty-four of 557 (11.5%) cases showed highly variable expression of HepPar-1 in 1% to 75% of tumor cells with a characteristically strong granular "mitochondrial" pattern. Only 13 cases (2.3%) expressed HepPar-1 in greater than 10% of the tumor cells. No correlation was seen with Gleason grade. On the other hand, 19 (3.4%) of 557 cases showed variable nonspecific cytoplasmic expression of Arg-1 distinct from the specific combined nucleocytoplasmic staining seen in normal liver and in HCC. Specifically, this Arg-1 pattern was seen only using one antibody lot and not another suggesting cross-reactivity. Only a single case showed specific nucleocytoplasmic expression of Arg-1 in the tumor cells. In conclusion, specific granular cytoplasmic staining for HepPar-1 is frequent in prostatic adenocarcinomas (11.5%) but usually focal and limited to less than 5% of tumor cells. This should not be misinterpreted as evidence of HCC, particularly in solid-pattern neoplasms. On the other hand, specific Arg-1 expression is very rare (0.18%), highlighting the value of Arg-1 in distinguishing HepPar-1-positive prostatic carcinoma from HCC at metastatic sites or in cases of liver metastasis from prostate carcinoma.
authors.affiliation: Institute of Pathology, Friedrich-Alexander University of Erlangen-Nuremberg, University Hospital, Erlangen, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Giedl
authors.affiliation: Section for Nephropathology, Friedrich-Alexander University of Erlangen-Nuremberg, University Hospital, Erlangen, Germany.
authors.forename: Maike
authors.initials: M
authors.lastname: Büttner-Herold
authors.affiliation: Department of Urology, Friedrich-Alexander University of Erlangen-Nuremberg, University Hospital, Erlangen, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Wach
authors.affiliation: Department of Urology, Friedrich-Alexander University of Erlangen-Nuremberg, University Hospital, Erlangen, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Wullich
authors.affiliation: Institute of Pathology, Friedrich-Alexander University of Erlangen-Nuremberg, University Hospital, Erlangen, Germany.
authors.forename: Arndt
authors.initials: A
authors.lastname: Hartmann
authors.affiliation: Institute of Pathology, Friedrich-Alexander University of Erlangen-Nuremberg, University Hospital, Erlangen, Germany. Electronic address: abbas.agaimy@uk-erlangen.de.
authors.forename: Abbas
authors.initials: A
authors.lastname: Agaimy
mesh_terms: D000230:Adenocarcinoma / Q000201:enzymology* / Q000556:secondary; D000951:Antigens, Neoplasm / Q000032:analysis*; D001119:Arginase / Q000032:analysis*; D014408:Biomarkers, Tumor / Q000032:analysis*; D001706:Biopsy; D006528:Carcinoma, Hepatocellular / Q000201:enzymology* / Q000556:secondary; D002454:Cell Differentiation; D003937:Diagnosis, Differential; D006801:Humans; D007150:Immunohistochemistry; D008113:Liver Neoplasms / Q000201:enzymology* / Q000556:secondary; D008297:Male; D060787:Neoplasm Grading; D011237:Predictive Value of Tests; D011471:Prostatic Neoplasms / Q000201:enzymology* / Q000556:secondary; D046888:Tissue Array Analysis
chemical_list: D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; C000600022:HepPar-1 protein, human; C574619:ARG1 protein, human; D001119:Arginase
keywords: Adenocarcinoma; Arginase-1; HCC; HepPar 1; Hepatoid; Prostate