title: HepPar-1 and Arginase-1 Immunohistochemistry in Adenocarcinoma of the Small Intestine and Ampullary Region.
abstract: CONTEXT :HepPar-1 and Arginase-1 are urea cycle enzymes used to distinguish hepatocellular carcinoma from other carcinomas. HepPar-1, but not Arginase-1, is known to be immunoreactive with normal human small intestine.
  
  
  OBJECTIVE
  To better define and compare the immunohistochemical staining patterns of HepPar-1 and Arginase-1 in adenocarcinomas arising in the small intestine, including the ampullary region.
  
  
  METHODS
  Staining for HepPar-1 and Arginase-1 was performed on 20 nonampullary small intestinal adenocarcinomas and 32 adenocarcinomas from the ampullary region. Ampullary adenocarcinomas were divided into intestinal morphology (15), pancreatobiliary morphology (14), and unclassifiable (3). Nonneoplastic small intestinal mucosa and colorectal adenocarcinomas were used as control groups.
  
  
  RESULTS
  HepPar-1 stained 12 of 20 nonampullary small intestinal adenocarcinomas, with a median of 63% of cells staining in positive cases. It also stained 11 of 15 ampullary carcinomas with intestinal morphology, with a median of 75% of cells staining in positive cases. Two of 14 ampullary carcinomas with pancreatobiliary morphology were positive for HepPar-1. Arginase-1 showed positivity in 2 ampullary region carcinomas and diffuse positivity in 1 duodenal adenocarcinoma. Two of 22 colorectal carcinomas stained for HepPar-1 with none positive for Arginase-1.
  
  
  CONCLUSIONS
  HepPar-1, but not Arginase-1, usually shows positivity in small intestinal adenocarcinomas and ampullary adenocarcinomas with intestinal morphology, but only rarely shows positivity in ampullary adenocarcinomas with pancreatobiliary morphology. HepPar-1 positivity in metastatic adenocarcinoma with intestinal morphology is suggestive of an upper gastrointestinal primary site.
authors.affiliation: From the Department of Pathology and Cell Biology, New York Presbyterian Hospital-Columbia University, New York (Drs Lagana, Hsiao, Sepulveda, Lefkowitch, and Remotti); the Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania (Dr Hsaio); the Department of Pathology, Scripps Clinic, San Diego, California (Dr Bao); and the Department of Pathology, Mayo Clinic, Rochester, Minnesota (Dr Moreira).
authors.forename: Stephen
authors.initials: S
authors.lastname: Lagana
authors.forename: Susan
authors.initials: S
authors.lastname: Hsiao
authors.forename: Fei
authors.initials: F
authors.lastname: Bao
authors.forename: Antonia
authors.initials: A
authors.lastname: Sepulveda
authors.forename: Roger
authors.initials: R
authors.lastname: Moreira
authors.forename: Jay
authors.initials: J
authors.lastname: Lefkowitch
authors.forename: Helen
authors.initials: H
authors.lastname: Remotti
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis / Q000378:metabolism*; D014670:Ampulla of Vater; D000951:Antigens, Neoplasm / Q000378:metabolism*; D001119:Arginase / Q000378:metabolism*; D000071616:CDX2 Transcription Factor; D018398:Homeodomain Proteins / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D007421:Intestine, Small / Q000378:metabolism* / Q000473:pathology; D053554:Keratin-20 / Q000378:metabolism; D053552:Keratin-7 / Q000378:metabolism; D046888:Tissue Array Analysis
chemical_list: D000951:Antigens, Neoplasm; D000071616:CDX2 Transcription Factor; C491270:CDX2 protein, human; C000600022:HepPar-1 protein, human; D018398:Homeodomain Proteins; D053554:Keratin-20; D053552:Keratin-7; C574619:ARG1 protein, human; D001119:Arginase